GB2638128A - Component for manipulating an input shockwave - Google Patents

Abstract

A component suitable for manipulating an input shockwave to produce localised energy concentrations. The component comprises a body 3 comprising a first material. One or more cavities 11 are defined within the body 3. The one or more cavities 11 are configured to manipulate the input shockwave. At least one of the one or more cavities 11b-e comprises a cavity suitable for containing fluid. The body 3 defines a channel 27 extending from the cavity 11b-e for containing fluid through the first material. The channel 27 is configured to fluidically connect the cavity 11b-e for containing fluid to a further volume (figure 3, 35). A method of manufacturing a component suitable for manipulating shockwaves is also disclosed as comprising the steps of stacking a plurality of plates (figure 5), wherein at least one of the first plates 31, and at least another of the plurality of plates are brought together in a fluid-filled environment such that the cavity defined by the at least one of the first plates contains the fluid from the fluid filled environment.

Description

Component for Manipulating an Input Shockwave This invention relates to a component for manipulating a shockwave to produce localised energy concentrations. Further, this invention relates to a method of manufacture of a component for manipulating an input shockwave to produce localised energy concentrations.

It has been shown in WO 2011/138622 that an interaction between a shockwave in a non-gaseous medium and a gaseous medium can generate a high speed transverse jet of the non-gaseous medium that moves through the gaseous medium. This results in the jet impacting on and trapping a volume of the gaseous medium, e.g. against a target, which gives rise to an intense concentration of energy within the gas.

The present invention aims to provide components, and methods of manufacture of such components, for use in alternative techniques for producing localised energy concentrations.

When viewed from a first aspect, the invention provides a component for manipulating an input shockwave to produce localised energy concentrations, wherein the component comprises: a body comprising a first material; one or more cavities defined within the body, wherein the one or more cavities is configured to manipulate the input shockwave so as to produce a manipulated shockwave; wherein at least one of the one or more cavities comprises a cavity for containing fluid; wherein the body defines a channel extending from the cavity for containing fluid through the first material; wherein the channel is configured to fluidically connect the cavity for containing fluid to a further volume.

The invention thus provides a component that manipulates a shockwave, when the shockwave is incident upon the component. The one or more cavities (e.g. a shockwave-manipulating volume at least partially defined by the one or more cavities) is configured to manipulate (e.g. modify the shape and/or intensity of) an input shockwave that is incident upon (e.g. an input face of) the component. The one or more cavities is arranged (e.g. shaped) to manipulate the shockwave as it passes through (e.g. to an output face of) the component.

Each cavity is a volume (e.g. chamber) defined within the body. Each cavity may be configured to contain a material that may be (and preferably is) different from the first material. One or more of the cavities may contain a vacuum. One or more of the one or more cavities is a cavity for containing fluid. In embodiments one or more (e.g. all) of the one or more cavities contains a fluid, and thus the cavity may be referred to as a "fluid-containing cavity".

The one or more cavities may be arranged between the input face and the output face of the component, e.g. such that a shockwave propagating through the component, from the input face to the output face, passes through each of the one or more cavities, e.g. successively. Preferably the one or more cavities are arranged along a direction between the input face and the output face of the component, e.g. a longitudinal central axis of the body (e.g. extending (e.g. perpendicularly) between the (e.g. centre of the) input face and the (e.g. centre of the) output face) may pass through (e.g. each of) the one or more cavities. The one or more cavities may (e.g. each) be substantially rotationally symmetric about the longitudinal central axis.

A channel, defined in the body of the component, extends from the at least one cavity for containing fluid. It will be understood that the channel extends from the cavity for containing fluid through the first material (e.g. away from the shockwavemanipulating volume).

The channel is fluidically connected to the cavity for containing fluid and is arranged to fluidically connect the cavity for containing fluid to a further volume, i.e. the channel is suitable for fluidically connecting the cavity for containing fluid to a further volume. It will be understood that the channel may fluidically connect the cavity for containing fluid to the further volume directly or indirectly. For example, the channel may fluidically connect the cavity for containing fluid to a first volume, which is itself fluidically connected to a second volume that may be the further volume. It will further be understood that a portion of the channel (e.g. distal from the cavity for containing fluid) may be considered to be the further volume. In some embodiments, the component comprises the further volume. In some embodiments the further volume is provided as a separate entity, e.g. external to the component.

The channel may have a cross sectional area which is (e.g. significantly) smaller than the cross-sectional area of the cavity for containing fluid. The further volume may have a cross-sectional area which is (e.g. significantly) greater than the cross-sectional area of the channel.

Thus, it will be seen that since the component is configured such that the cavity for containing fluid can be fluidly connected to a further volume, when fluid is inside the cavity, the fluid is not hydrostatically locked (e.g. is less constrained, e.g. has freedom to move and/or expand) and so the component may have a higher tolerance to temperature fluctuations.

In embodiments, the further volume may comprise a pressure inlet for pressurising the at least one cavity for containing fluid. Thus the pressure inlet may be configured to allow the at least one cavity for containing fluid to be pressurised (e.g. via the further volume). Pressurising the cavity for containing fluid may reduce the presence of bubbles inside the cavity for containing fluid (particularly in cases where the cavity for containing fluid contains liquid). It may be advantageous to reduce the presence of bubbles inside the cavity for containing fluid since any imperfections (e.g. bubbles) in the shockwave-manipulating volume may negatively affect the function of the shockwave-manipulating volume.

The one or more cavities for containing fluid may be any suitable and desired shape. In embodiments, at least one of the one or more cavities (e.g. each) have a lateral dimension (e.g. extending substantially perpendicularly to the longitudinal central axis of the body) that is greater than a respective thickness of the cavity. The thickness may be defined as the dimension that is perpendicular to the lateral dimension of the cavity and/or perpendicular to the input face and/or output face of the body (and thus may be substantially parallel to the longitudinal central axis of the body).

In embodiments, at least one of the one or more cavities (e.g. each) have a substantially uniform thickness. In embodiments, at least one of the one or more cavities (e.g. each) have a non-uniform (e.g. variable) thickness.

In embodiments, an input face and/or output face of at least one (e.g. each) of the one or more cavities is substantially flat. Thus, in embodiments, at least one (e.g. each) of the one or more cavities is substantially cylindrical (e.g. squat cylindrical).

In embodiments, the input face and/or the output face of at least one (e.g. each) of the one or more cavities comprises a (e.g. continuously) curved portion. Thus, in embodiments, at least one (e.g. each) of the one or more cavities is a non-cylindrical (e.g. non-planar) volume (although it may have a substantially uniform thickness, for example).

In embodiments, the body comprises a plurality of stacked plates, wherein the plurality of stacked plates comprises one or more first plates. Preferably, (e.g. each of) the first plates defines a cavity (i.e. one of the one or more cavities). The first plates may thus be "cavity-defining plates". Preferably, the stacked plates are stacked (e.g. one on top of each other) in a direction between the input face and the output face of the component. Thus, the stacked plates (e.g. each) extend in a direction substantially perpendicularly to the direction (e.g. the longitudinal central axis) between the input face and the output face of the component.

In embodiments, the plurality of stacked plates are arranged such that the one or more cavities (in the shockwave-manipulating volume) are arranged between the input face and the output face of the component, e.g. along a direction between the input face and the output face of the component, e.g. a longitudinal central axis of the body (e.g. extending (e.g. perpendicularly) between the (e.g. centre of the) input face and the (e.g. centre of the) output face) may pass through (e.g. each of) the one or more cavities.

In embodiments, one or more of the first plates comprises a recess (e.g. depression, indent, etc.) defining the cavity. Thus, the cavity may not extend through the entire depth of the respective plate. In such embodiments, adjacent cavities may not be separated by a further (second) plate, but rather by a portion of the first (cavity-defining) plate that defines the cavity.

In embodiments, the plurality of plates comprises one or more second plates. Thus, in some embodiments, the plurality of plates comprises one or more first plates and one or more second plates. Preferably, the one or more second plates are (e.g. each) different (e.g. in shape and/or size) from the one or more first plates. Preferably, the one or more second plates do not define a cavity. Thus, the one or more second plates are flat and/or solid and/or have a substantially constant thickness (e.g. across their surface area).

In embodiments, one or more of the first plates comprises an aperture (e.g. a through-hole) defining the cavity. Thus, the cavity may extend through the entire thickness of the respective plate (e.g. from one surface of the plate to the opposite surface of the plate).

The plurality of plates may comprise one or more of the second plates adjacent one or more of the one or more first plates, e.g. adjacent the aperture(s) in the first plates. In embodiments, the one or more first plates and the one or more second plates are arranged (e.g. stacked) such that the plates alternate between first plates and second plates. For example, (each of) one or more of the first plates is adjacent (sandwiched between) two of the second plates and/or (each of) one or more of the second plates is adjacent (sandwiched between) two of the first plates. This results in a shockwave-manipulating volume that contains multiple parallel layers, alternating between cavities (that may be filled with a cavity-fill material (a fluid), thus forming cavity-fill material (fluid-filled) layers, e.g. low shock-impedance layers) and second plate material layers (e.g. high shock-impedance layers).

Providing multiple layers within the shockwave-manipulating volume helps to superimpose components of the input shockwave that are reflected from the boundaries between the layers (e.g. the boundaries between the cavities). This helps to amplify the intensity of the shockwave between the input face and the output face of the component.

Although, each cavity may be separated from the adjacent cavities by a second plate, or by a part of a first plate that defines a cavity, it will be understood that the one or more cavities together combine to form a shockwave-manipulating volume.

The plates may have any suitable and desired thickness (the dimension perpendicular to the direction (e.g. plane) in which the plates extend). For example, each of the first plates has the same thickness and/or each of the second plates has the same thickness. In embodiments, the one or more first plates (e.g. each) have different thicknesses. In embodiments, the one or more second plates (e.g. each) have different thicknesses.

The (e.g. first and/or second plates of the) plurality of plates may be shaped to define the shape of the one or more cavities. In embodiments, at least one of the (e.g. first and/or second plates of the) plurality of plates (e.g. each) have a substantially uniform thickness. In embodiments, at least one of the (e.g. first and/or second plates of the) plurality of plates (e.g. each) have a non-uniform (e.g. variable) thickness.

In embodiments, an input face and/or an output face of at least one (e.g. each) of the (e.g. first and/or second plates of the) plurality of plates is substantially flat.

When adjacent plates are flat (and, e.g., parallel), they may define a cavity therebetween that has a substantially uniform thickness and, for example, is substantially cylindrical.

In embodiments, the input face and/or the output face of at least one (e.g. each) of the (e.g. first and/or second plates of the) plurality of plates comprises a (e.g. continuously) curved portion. When adjacent plates have at least a portion thereof that is curved, they may define a cavity therebetween that is non-cylindrical (e.g. non-planar).

In embodiments, at least one of the (e.g. first and/or second plates of the) plurality of plates (e.g. each) have a lateral dimension (the dimension in which the plates extend, e.g. substantially perpendicularly to the longitudinal central axis of the body) that is greater than a respective thickness of the plate.

In embodiments, the channel is configured to fluidically connect the at least one cavity for containing fluid to an expansion chamber (e.g. the further volume comprises an expansion chamber). The expansion chamber may be a part of the component (i.e. the component may comprise the expansion chamber), or the expansion chamber may be provided as a separate entity, e.g. external to the component. Any (e.g. substantially enclosed) volume into which the fluid is allowed to expand (e.g. as a result of temperature induced pressure fluctuations) may be considered to be an expansion chamber.

The Applicant has appreciated that, when fluid is sealed inside a cavity, there is no allowance for expansion, for example owing to temperature induced pressure fluctuations. As a result, when a component with fluid-filled cavities is subject to temperature fluctuations, the component may be forced apart by the increased pressure of the fluid, with seals being breached. This is, of course, undesirable.

By providing an expansion chamber to which the at least one cavity for containing fluid is fluidically connected, any fluid inside the cavity is not hydrostatically locked (e.g. is less constrained) and so the component may have a higher tolerance to temperature fluctuations.

This is considered to be novel and inventive in its own right and thus, when viewed from a second aspect, the invention provides a component for manipulating an input shockwave to produce localised energy concentrations, wherein the component comprises: a body comprising a first material; one or more cavities defined within the body, wherein the one or more cavities is configured to manipulate the input shockwave so as to produce a manipulated shockwave; wherein at least one of the one or more cavities comprises a cavity for containing fluid; wherein the body defines a channel extending from the cavity for containing fluid through the first material; wherein the channel is configured to fluidically connect the cavity for containing fluid to an expansion chamber.

It will be appreciated that this aspect may (and preferably does) include one or more (e.g. all) of the preferred and optional features disclosed herein, e.g. relating to other aspects and embodiments of the invention, as applicable. For example, the component may comprise the expansion chamber or the expansion chamber may be provided separately from the component, e.g. the expansion chamber may be external to the component.

In embodiments, the component comprises a plurality of cavities defined within the body.

In embodiments, at least two cavities are cavities for containing fluid, e.g. fluid-containing cavities.

In embodiments, the two cavities for containing fluid are fluidically connected to each other. In embodiments, the channel is configured to fluidically connect the at least two cavities for containing fluid. In embodiments, the two fluidically connected cavities are arranged to contain the same fluid.

In such embodiments, the two cavities for containing fluid may be considered to be first and second cavities for containing fluid. In such embodiments, the channel is configured to fluidically connect the first cavity for containing fluid to the second cavity for containing fluid. Thus, the further volume may comprise the second cavity for containing fluid.

In embodiments, the component may comprise a separate channel for (extending from) each cavity for containing fluid. Thus, the component may comprise a plurality of cavities for containing fluid and the body may define a plurality of channels extending from the respective plurality of fluid-filled cavities through the first material.

By providing a fluidic connection between two cavities for containing fluid, the fluid inside each of the connected cavities is not hydrostatically locked inside the cavity (e.g. is less constrained) and so the component may have a higher tolerance to temperature fluctuations. Further, a fluidic connection between cavities for containing fluid may allow the cavities for containing fluid to be pressurised using a single pressure inlet, which is, e.g., connected to each of the plurality of channels.

This is considered to be novel and inventive in its own right and thus, when viewed from a third aspect, the invention provides a component for manipulating an input shockwave to produce localised energy concentrations, wherein the component comprises: a body comprising a first material; a plurality of cavities defined within the body, wherein the plurality of cavities is configured to manipulate the input shockwave so as to produce a manipulated shockwave; wherein the plurality of cavities comprises at least one first cavity for containing fluid and at least one second cavity for containing fluid; wherein the body defines a channel extending from the first cavity for containing fluid through the first material; wherein the channel is configured to fluidically connect the first cavity for containing fluid to the second cavity for containing fluid.

It will be appreciated that this aspect may (and preferably does) include one or more (e.g. all) of the preferred and optional features disclosed herein, e.g. relating to other aspects and embodiments of the invention, as applicable.

In embodiments, at least two of the cavities for containing fluid (e.g. are arrange to) contain different (e.g. respective) fluids. It will be understood that the term fluid encompasses both liquids and gases. It may be desirable for different cavities for containing fluid to contain different liquids, different gases, or a combination of different liquids and gases.

In embodiments, the body defines a channel for (extending from) each of the cavities for containing fluid (e.g. cavities for containing different fluids). Preferably, the channels are configured to fluidically connect the cavities for containing fluid to different (respective) expansion chambers. Where different cavities for containing fluid are arranged to contain different fluids, a common expansion chamber may lead to cross-contamination between the fluids, and so separate channels to connect each cavity for containing fluid to respective expansion chambers helps to avoid such contamination.

Where two or more cavities for containing fluid are arranged to contain the same fluid, the channels connected to (extending from) these (e.g. respective) cavities may be configured to connect the two or more cavities for containing fluid to a common expansion chamber.

In embodiments, the body defines one or more channels extending from (e.g. each) cavity for containing fluid through the first material, e.g. away from the shockwave-manipulating volume. The one or more channels may (e.g. each) extend in a direction substantially perpendicularly to the direction between the input face and the output face of the component. Thus, when the body comprises a plurality of stacked plates, the one or more channels may (e.g. each) extend in a direction substantially parallel to the direction in which the (e.g. respective) plates extend.

In embodiments, the body defines one or more channels extending through the first material, wherein the one or more channels are configured to fluidically connect the first cavity for containing fluid to the second cavity for containing fluid within the body (e.g. the first and second cavities are connected by one or more channels within the body of the component, e.g. the channels do not extend to an outside edge of the body).

In embodiments, the body defines one or more channels extending from (e.g. each) cavity for containing fluid through the first material to an outside edge of the body.

This allows the (e.g. each) cavities for containing fluid to be fluidically connected to a further volume (e.g. another of cavity and/or an expansion chamber) via the one or more channels.

In the embodiments in which the body comprises a plurality of stacked plates, one or more of the plurality of plates (e.g. the first plate(s) and/or the second plate(s)) may (e.g. each) comprise a groove in (extending across) a surface of the plate. One or more of the channels may be defined by the groove(s) and, e.g., a surface of an adjacent plate.

In the embodiments in which the body comprises a plurality of stacked plates one or more of the plurality of plates (e.g. the first plate(s) and/or the second plate(s)) may comprise a bore that extends through the material of the plate, e.g. from the cavity for containing fluid, e.g. to an external (e.g. circumferential) edge of the plate. One or more of the channels may be defined by the bore(s). The bore(s) preferably extend in a direction substantially parallel to the direction in which the (e.g. respective) plates extend.

In embodiments, the component comprises a housing within which the body is at least partially received. The housing may define a volume (e.g. recess) into which the body is at least partially received. Preferably the volume of the housing, for receiving the body, and the body are arranged substantially coaxially, e.g. on the central longitudinal axis of the component.

In embodiments, the body comprises a plurality of stacked plates, comprising one or more first plates. Each of the first plates defines a cavity. The housing may be configured to maintain the alignment of the plurality of stacked plates when the body is at least partially received within the housing.

In embodiments, the housing defines one or more ducts that are fluidically connected to the channel(s) such that each cavity for containing fluid can be fluidically connected to an expansion chamber, and/or to another cavity for containing fluid via (at least) a channel(s) (e.g. the channel of one or both of the cavities for containing fluid) and one or more of the ducts. The one or more ducts may comprise a primary portion, and one or more conduits. The one or more conduits may be configured such that each conduit aligns (e.g. is coaxial) with a channel such that the channels are fluidically connected to the primary portion of the duct via the conduits of the duct.

In embodiments in which at least two cavities are cavities for containing fluid, the respective channels extending from these cavities are preferably fluidically connected to a common duct, such that the at least two cavities are fluidically connected via the common duct. Thus, the at least two cavities are preferably cavities for containing fluid configured to contain (and preferably that contain) the same fluid.

In embodiments, at least one (e.g. each) cavity for containing fluid contains a fluid.

In embodiments, at least one (e.g. each) cavity for containing fluid contains a gas.

In embodiments, at least one (e.g. each) cavity for containing fluid contains a liquid.

Preferably the fluid has a lower shock-impedance than a shock-impedance of the first material. Thus, in some embodiments, the body comprises a plurality of layers (cavities and layers of the first material) that alternate between low shock-impedance material and high shock-impedance material.

When viewed from a fourth aspect, the invention provides a system comprising a component as defined in any of the previous aspects, and an expansion chamber fluidically connected to the at least one cavity for containing fluid.

It will be appreciated that this aspect may (and preferably does) include one or more (e.g. all) of the preferred and optional features disclosed herein, e.g. relating to other aspects and embodiments of the invention, as applicable. For example, preferably the at least one cavity for containing fluid contains a fluid. Preferably the expansion chamber is fluidically connect to the at least one cavity for containing fluid via the channel extending from the cavity.

In embodiments, the expansion chamber may comprise a pressure inlet configured to allow the at least one cavity for containing fluid to be pressurised (e.g. via the expansion chamber).

In embodiments, the system comprises a plurality of expansion chambers which are fluidically isolated from one another. Each expansion chamber may be fluidically connected to at least one cavity for containing fluid.

In embodiments, the system is a closed system, e.g. the fluid in the at least one cavity for containing fluid is sealed within the system.

As well as the component, the Applicant has also devised a method of manufacturing the component. When viewed from a fifth aspect, the invention provides a method of manufacturing a component for manipulating an input shockwave to produce localised energy concentrations, wherein the component comprises a component according to any of the first, second or third aspects; wherein the body of the component comprises a plurality of stacked plates; wherein the plurality of stacked plates comprises one or more first plates; wherein each of the first plates defines a cavity for containing fluid; wherein the method comprises: stacking the plurality of plates; wherein at least one of the first plates and at least another of the plurality of plates are brought together in a fluid-filled environment, such that the cavity for containing fluid defined by the at least one of the first plates contains (some of) the fluid from the fluid-filled environment.

It will be appreciated that this aspect may (and preferably does) include one or more (e.g. all) of the preferred and optional features disclosed herein, e.g. relating to other aspects and embodiments of the invention, as applicable. In particular, the component may include one or more (e.g. all) of the preferred and optional features disclosed herein relating to the component. The method may comprise include one or more (e.g. all) of the preferred and optional features disclosed below relating to the method.

It will be understood that in embodiments where at least one first plate defining the cavity for containing fluid comprises a recess that defines the cavity, only one further plate (another of the plurality of plates) needs to be brought together with the at least one first plate in a fluid-filled environment in order for the cavity to contain the fluid. However, in embodiments where the at least one first plate defining the cavity for containing fluid comprises an aperture (e.g. through-hole) defining the cavity, at least two further (second) plates (of the plurality of plates) need to be brought together with the at least one first plate (e.g. sandwiching the first plate) in a fluid-filled environment in order for the cavity to contain the fluid.

When viewed from a sixth aspect, the invention provides a method of manufacturing a component for manipulating an input shockwave to produce localised energy concentrations, wherein the component comprises: a body comprising a first material; one or more cavities defined within the body, wherein the one or more cavities is configured to manipulate the input shockwave so as to produce a manipulated shockwave; wherein at least one of the one or more cavities comprises a cavity for containing fluid; wherein the body comprises a plurality of stacked plates; wherein the plurality of stacked plates comprises one or more first plates; wherein each of the first plates defines a cavity comprises a cavity for containing fluid; and wherein the method comprises: stacking the plurality of plates; wherein at least one of the first plates and at least another of the plurality of plates are brought together in a fluid-filled environment, such that the cavity defined by the at least one of the first plates contains (some of) the fluid from the fluid-filled environment.

It will be appreciated that this aspect may (and preferably does) include one or more (e.g. all) of the preferred and optional features disclosed herein, e.g. relating to other aspects and embodiments of the invention, as applicable. In particular, the component may include one or more (e.g. all) of the preferred and optional features disclosed herein relating to the component.

In embodiments, the component comprises a housing within which the body is at least partially received, the method comprising stacking the plurality of plates into the housing, wherein the housing is configured to align (e.g. arrange in a correct position relative to one another) the plurality of plates.

In embodiments, the fluid (of the fluid-filled environment) is a liquid, and placing the at least one of the first plates in a fluid-filled environment comprises submerging the at least one of the first plates in a liquid bath.

The method may comprise assembling any (e.g. one, more or all) of the parts of the component within the fluid-filled environment (e.g. submerging in the liquid bath), in particular bringing the first and another plates together to form the fluid-filled cavities of the component.

In embodiments, the method comprises de-gassing the liquid before the at least one of the first plates is submerged in the liquid bath.

In embodiments, de-gassing the liquid may comprise placing a container of liquid inside a vacuum chamber held at low vacuum, e.g. less than 10 mbar, e.g. less than 5 mbar, e.g. for an extended period of time (e.g. 24 hours) in order to draw dissolved gas out of the liquid.

In embodiments, de-gassing the liquid may comprise ultrasonically de-gassing the liquid.

In embodiments, the method comprises ultrasonically cleaning the plates that are brought together in the fluid-filled environment, before stacking the plurality of plates. This helps to reduce the likelihood of bubbles forming on the plates.

According to a seventh aspect, the invention provides a method of using a system according to the fourth aspect, the method comprising pressurising the expansion chamber so as to apply pressure to the cavity for containing fluid.

It will be appreciated that this aspect may (and preferably does) include one or more (e.g. all) of the preferred and optional features disclosed herein, e.g. relating to other aspects and embodiments of the invention, as applicable. In particular, preferably the cavity for containing fluid contains a fluid.

The method may comprise pressurizing the expansion chamber to a pressure in the range 1.5 bar to 5 bar. In embodiments, the method may comprise pressurising the expansion chamber to a pressure of approximately 2 bar.

In embodiments where a plurality of expansion chambers are provided, the method may comprise applying different pressures to different expansion chambers, e.g. depending on the fluids that are being pressurised.

The component may have any suitable and desired dimensions, and the dimensions may be determined by the specific application of the component. In one embodiment the (e.g. layered component cavity of the) component has a thickness, diameter and/or maximum dimension between 0.1 mm and 100 mm, e.g. between 1 mm and 50 mm, e.g. between 2 mm and 10 mm, e.g. approximately 3 mm, 5 mm or 8 mm.

It will be understood that where used herein, the term "shock-impedance" is intended to mean "'the pressure which must be applied to a medium in order to impart a unit particle velocity to some of the medium" (Henderson, 'On the refraction of shock waves', Journal of Fluid Mechanics, Volume 198, January 1989, pages 365-386). This is equal to the product of the shock speed and the density of the un-shocked material.

It will be understood that the input shockwave may be formed outside of the (e.g. body of the) component and propagate into the component, but may additionally or alternatively be generated in the component, for example by the (e.g. body of the) component being struck (e.g. by a projectile). Both alternatives are covered by the wording "input shockwave".

Certain embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a plan view of a component; Figure 2 shows a perspective cutaway view of the component of Figure 1; Figure 3 shows shows a schematic cross-sectional side view of a system including the component of Figure 1; Figure 4 shows a schematic cross-sectional side view of the component of Figure 1 in use; Figure 5 shows an exploded view of the component of Figure 1; Figure 6 shows a flow chart illustrating a method of manufacture of the component of Figure 1; Figure 7 shows a variant of the component shown in Figures 1 to 5; Figure 8 shows a variant of the system of Figure 3; and Figure 9 shows a schematic cross-sectional side view of a variant of the component shown in Figures 1 to 5.

It will be understood that where used herein, the terms "top", "bottom", "up", "down", "side", "base", "vertical", "horizontal", etc. are included for clarity and are intended to refer to the orientation shown in the enclosed Figures. It will be appreciated that, in use, the components and systems may operate in any suitable and desired orientation.

It will be understood that each of the components described herein may be configured to be used at part of a nuclear fusion process. However, it will also be understood that the components described herein are not limited to such applications and may be configured to be used as part of other processes where the production of localised energy concentrations is desirable. For example, the components described herein may be used to encourage chemical reactions or to produce localised energy concentrations for the testing of safety equipment (e.g. helmets).

Figure 1 shows a plan view of a component 1 for manipulating an input shockwave to produce localised energy concentrations. The component comprises a body 3, and a housing 5 in which the body 3 is received. Both the body 3 and the housing 5 are cylindrical. It can be seen from Figure 1 that the body 3 and the housing 5 are concentric. Ducts 7a, 7b, are defined in the housing 5 and (the external apertures formed by the ducts) are visible in Figure 1. Although a pair of ducts is shown in the embodiment of Figure 1, in embodiments, only a single duct may be provided. The body 3 defines a shockwave-manipulating volume 20.

Figure 2 shows a perspective cutaway view of the component 1. The cross-section of Figure 2 is taken along line A-A shown in Figure 1.

The component 1 has an input face 10 and an output face 12. The input face 10 is configured to receive an input shockwave, and the output face 12 is configured to output a manipulated shockwave (as explained below in relation to Figure 4).

The component 1 comprises a body 3 that defines a plurality of cavities 11. Each cavity 11 has a conic frustum shape and is at least partially defined by a cavity wall 13. Each cavity has an input, and an output. The input receives the shockwave, and the shockwave exits the cavity from output.

The cavities 11 are aligned such that they share a common central axis 15 (e.g. the longitudinal axis around which each cavity is rotationally symmetrical is coaxial with the longitudinal axis of the other cavities). The body 3 is formed of a material having a high shock-impedance.

The cavities 11 contain one or more cavity fill materials having a low shock-impedance. The cavity fill materials have a lower shock-impedance than that of the body 3. Between the cavities 11, a plurality of thin high shock-impedance layers 19 are provided.

As such, the cavities 11 and high shock-impedance layers 19 combine to create a shockwave-manipulating volume 20 that contains a plurality of layers, alternating between low shock-impedance layers 21 (cavities 11), and high shock-impedance layers 19.

The body 3 (e.g. the plates) may be formed of tantalum, but the body could be formed from any suitable material, e.g. any other suitable (heavy) metal such as platinum, copper, steel, tungsten, or alloys thereof. In embodiments, one or more surfaces of the body 3 may be coated with a hydrophilic coating which may reduce the formation of bubbles on the coated surfaces. In embodiments, one of more surfaces of the body 3 may be coated with a barrier coating which may reduce galvanic corrosion of the coated surfaces. In embodiments, a coating may be applied to one or more surfaces of the body 3 which is both a barrier coating and a hydrophilic coating.

At least one of the cavity fill materials is a fluid (e.g. a liquid or a gas). In the body 3 shown in Figures 1 and 2, five cavities 11a, b, c, d, e are defined. The top cavity 11 a partially defines the input face 10 of the component 1 and is a solid-containing cavity that is configured to contain a solid cavity fill material. The other, lower cavities 11b, 11 c, 11d, le are fluid-containing cavities that are configured to contain a fluid. In an exemplary embodiment, the solid cavity fill material is polymethyl methacrylate (PMMA), but could be any suitable material.

As explained above, the shockwave-manipulating volume 20 comprises a plurality of parallel low shock-impedance layers 21 (cavities 11) and a plurality of high shock-impedance layers 19 formed from a high shock-impedance material (tantalum in an exemplary embodiment). The high shock-impedance layers 19 are formed of a material having a higher shock-impedance than any cavity fill material (solid or fluid) that is present in any of the cavities 11 (i.e. the low shock-impedance layers 21).

The parallel layers alternate from low shock-impedance layers 21 to high shock-impedance layers 19 from one layer to the next. In the illustrated embodiment, the input layer (formed by cavity 11a) that partially forms the input face 10 of the component 1 is a low shock-impedance layer 21. However, the alternative is envisaged.

In the illustrated embodiment, the high shock-impedance layers 19 all have the same thickness, and the low shock-impedance layers 21 all have the same thickness. The thickness of the low-shock-impedance layers 21 is greater than the thickness of the low shock-impedance layers 19. However, it will be understood that the layers may have different thicknesses, and/or the thickness of any individual layer may vary across its width. Thickness will be understood to refer to the dimension that is substantially parallel to the longitudinal axis 15.

In the illustrated embodiment, for each of the fluid-containing cavities 11, the body defines a pair of channels 27. Each channel 27 extends from one of the fluid-containing cavities 11, through the first material of the body 3, to an external surface of the body 3. Each channel 27 extends in a direction perpendicular to the longitudinal axis 15.

The housing 5 of the component, in which the body 3 is located, defines a pair of ducts 7a, 7b. Each of the ducts 7a, 7b comprises a primary portion 29, and four conduits 28. The conduits 28 each align with a channel 27 such that each channel 27 is fluidically connected to a primary portion 29 of a duct via a conduit 28.

The conduits 28 extend in a direction perpendicular to the longitudinal axis 15 (i.e. the conduits 28 extend in a direction parallel to the direction in which the channels 27 extend). The conduits 28 are formed as cylindrical bores having a cross sectional area that is greater than the cross-sectional area of the channels 27. The primary portions 29 of the ducts 7a, 7b extend in a direction parallel to the longitudinal axis 15 (i.e. the primary portions 29 extend in a direction perpendicular to the direction in which the channels 27 and conduits 28 extend). The primary portions 29 are formed as cylindrical bores having a cross sectional area that is greater than the cross sections area of the conduits 28.

Each of the cavities 11 b, 11c, lid, 11e, are fluidically connected to each other via the channels 27, the conduits 28 and the ducts 7a, and 7b.

The primary portions 29 of the ducts 7a, 7b extend to the input surface 10 of the component 1 and, as such, define apertures 9a, 9b in the input surface 10 of the component 1. Expansion chambers may be connected to the apertures 9a, 9b, as explained below in relation to Figure 3.

Figure 3 shows a cross-sectional side view of the component 1 incorporated into a system 30. The cross section of Figure 3 is taken along line A-A shown in Figure 1.

In addition to the component 1, as described above in relation to Figure 2, the system 30 includes an expansion chamber 35 that is fluidically connected to the fluid-containing cavities 11b, 11c, 11d, 11e via the channels 27, the conduits 28 and the ducts 7a, 7b. The system 30 includes expansion lines 37 that are connected to the apertures 9a, 9b defined by the primary portions 29 of the ducts 7a, 7b. The -21 -expansion lines 37 fluidically connect the component 1 to the expansion chamber 35.

A problem that fluid-filled cavities present, is that when the fluid is sealed inside a cavity, there is no allowance for expansion, for example due to temperature induced pressure fluctuations. As a result, when a component with fluid-filled cavities is subject to temperature fluctuations, the component can be forced apart by the increased pressure of the fluid, with seals being breached. This is, of course, undesirable.

By providing a further volume (the expansion chamber 35) to which the fluid-containing cavities are fluidically connected, the fluid inside the cavities is less constrained and so the component has a higher tolerance to temperature fluctuations.

As explained above, one or more of the fluid-containing cavities may contain a liquid. A problem that is presented by liquid filled cavities is bubble formation. Since any imperfections in the shockwave-manipulating volume 20 can negatively affect the function of the shockwave-manipulating volume, it is important to reduce the presence of bubbles inside any liquid filled cavities. To this end, the expansion chamber 35 also comprises a pressure inlet 39. After having been assembled, and filled with liquid, the expansion chamber 35 (and thus the fluid-containing cavities 11b, 11c, 11d, 11e) may be pressurised using a pressurising apparatus (not shown) connected to the pressure inlet 39. Holding the liquid under pressure (for example 2 bar) may reduce the formation of bubbles by causing any gas that is dissolved in the liquid to stay dissolved.

Further, by elevating the pressure in the expansion chamber 35 the fluid can be maintained at a pressure above its vapour pressure. In some applications, the component 1 may be placed in a vacuum chamber when in use. Depending on the fluid, vacuum conditions may cause the fluid to change state. By increasing the static pressure in the expansion chamber 25, and hence in the fluid-containing cavities 11b-e, phase change may be avoided even when the component 1 is placed in a vacuum chamber.

It will be understood that where the fluid-filled cavities are filled with a gas, and not a liquid, bubbles may not cause a problem, and so the pressure inlet 39 may be omitted.

In the illustrated embodiment, a separate expansion chamber 35 is provided. It will be understood, however, that any further volume that is fluidically connected to the fluid-containing cavities, and which acts to allow the fluid in the cavities to expand may act as an expansion chamber.

In embodiments, the expansion chamber 35 may be omitted, and the expansion lines 37 may act as an expansion chamber. In such embodiments, the expansion lines 37 may be configured to connect to a pressurising apparatus (e.g. via a pressure inlet). In embodiments, at least a portion of the ducts 7a, 7b may act as the expansion chamber. In such embodiments, one or both of the apertures 9a, 9b may be configured to connect to a pressurising apparatus (e.g. the apertures 9a, 9b may act as a pressure inlet). The pressurising apparatus may, for example, comprise a source of pressurised gas.

Operation of the component 1 will now be explained with reference to Figure 4.

Figure 4 shows a cross-sectional profile view of the component 1 with some of the other features of the system (the expansion chamber 35, expansion lines 37, etc.) omitted for clarity. The input face 10 is configured to receive a shockwave. In the embodiment shown in Figure 4, this shockwave is generated by striking the input face 10 of the component 1 with a disc-shaped projectile 23. This strike generates a planar shockwave in the component 1 that is focussed by the component 1 onto a target 25, creating a localised concentration of energy at the location of the target 25.

On input into the shockwave-manipulating volume 20, the input shock reflects from the cavity walls 13 as an irregular shock reflection (Mach reflection) that propagates in from the cavity walls 13, eventually overlapping on the central axis 15 of the shockwave-manipulating volume 20. The overlap of this radially-symmetric wave on the central axis creates a high pressure point within the shockwave-manipulating volume 20, which expands and interacts with the impinging Mach reflection, leading to the generation of an axial, quasi-planar Mach stem that propagates towards the output face 12 of the component 1.

The high and low shock-impedance layers 19, 21 are arranged such that shockwaves generated at the input face 10 of the component 1 reverberate within the stack of layers 19, 21, as a result of reflections from the high shock-impedance layers 19, leading to regions of constructive and destructive interference as shock waves pass over one another. When a shock passes from a low shock-impedance layer 21 into a high shock-impedance layer 19, a portion of the shock is transmitted into the high shock-impedance layer 19, while a portion is reflected back into the low shock-impedance layer 21.

The portion in the low shock-impedance layer 21 speeds up since it is now travelling through pre-shocked material, the shock portion then reflects from the boundary at the input of the low shock-impedance layer 21, and since it has been sped up, the reflected portion eventually catches up with the portion of the shock that was initially transmitted into the high shock-impedance layer 19. Through the arrangement of the low and high shock-impedance layers 21, 19, the component 1 can be arranged such that a plurality of shock features superimpose at the output face 12 of the component 1, leading to a short-lived high shock pressure state that can be transmitted into a target 25 adjacent to the component output 12.

The combination of the focusing shape of the frustum shaped cavities 11 with the layers 19, 21, leads to a component design that has been shown to be capable of greatly increasing shock pressures on output, relative to either of the features individually. Shock reflections from the cavity walls 13 interact with axial shock reflections from the high shock-impedance layers 19, creating regions of locally high thermodynamic pressure. These high-pressure regions expand and interact with further shock reflections downstream in the component 1, creating regions with yet-higher shock pressure, that eventually pass through to the output face 12 of the component 1.

In addition to generating the conditions for local shock superposition and constructive interference, the layers 19, 21 also act to effectively slow the shock transit time through the component 1. This allows energy from more of the projectile 23 to be harvested and combined into a single shock state upon emergence from the component 1.

The component 1 may be formed by milling the body 3 to form the shockwave-manipulating volume 20, and then fitting the low shock-impedance layers 21 and the high shock-impedance layers 19 into the shockwave-manipulating volume 20. For example, each cavity 11 may be filled with its cavity fill material before the next high shock-impedance layer 19 is placed on top of the cavity fill material, at least partially sealing the cavity 11.

However, owing to the small dimensions (e.g. on the mm scale or less), it may be difficult to form the component 1 in this way, such that the tolerances between the layers 19, 21 themselves, and between the layers and the cavity walls 13, are acceptable. Further, placing the high shock-impedance layers 19 into position may be difficult without them becoming deformed or breaking. Since small imperfections in the component 1 may significantly influence the way the component 1 manipulates an input shockwave, these imperfections are undesirable.

In the illustrated embodiment, the body 3 of the component 1 comprises a plurality of stacked plates. By manufacturing and assembling the body 3 as a stack of plates, the shockwave-manipulating volume 20 may be fabricated with greater manufacturing accuracy. The plurality of plates comprises a plurality of first plates 31, which are cavity-defining plates, and a plurality of second plates 33, which are non-cavity-defining plates.

Figure 5 shows an exploded view of the first and second plates 31, 33 that are arranged to be stacked, to form the body 3, and received within the housing 5 to form the component 1 shown in Figures 1 to 4. In the view of Figure 5, the fluid-containing cavities 11 b, 11c, 11d, 11e are unfilled, while a solid fill element 41 is provided to be inserted into the solid-containing cavity 11a.

As can be seen from Figure 5, the first and second plates 31, 33 are stacked in an arrangement alternating between first plates 31 and second plates 33 from one plate to the next. Further, the first and second plates 31, 33 are aligned such that the longitudinal axis around which each plate is rotationally symmetrical is coaxial with the longitudinal axis of the other plates.

In the illustrated embodiment, the low shock-impedance layers 21 are formed by the cavities 11 defined by first plates 31, and the high shock-impedance layers 19 are formed as second plates 33. Both the first plates 31 and second plates 33 span the cross sectional area of the body 3, but the first plates 31 each define a cavity 11, while the second plates 33 are solid. The body 3 itself is therefore formed of layers. The cross sectional area of the shockwave-manipulating volume 20 is greater adjacent the input face 10 of the component 1 than it is adjacent the output face 12 of the component. In the illustrated embodiment, each cavity 11 is shaped as a conic frustum.

Each first plate 31 is a flat disc, defining a frusto-conical cavity 11 at its centre. The cavity 11 passes through the depth of the plate 31 such that the input and output of the cavity are open before the first plate 31 is stacked. Each second plate 33 is a solid flat disc.

In Figure 5, the first plates 31 are labelled 31a, 31b, 31c, 31d, 31e. It will be understood that the top plate 31a defines a respective cavity 11a, the next plate 31b defines a respective cavity 11 b, etc.. Each of the first plates 31b, 31c, 31d, 31e, which define a fluid-containing cavity, define two grooves 43 in their top surface. The grooves 43 are radial grooves and extend from the cavity 11 to an outside edge 45 of the plate. In the illustrated embodiment, the grooves are diametrically opposed.

When the plates 31, 33 are stacked together, each groove 43 results in a channel 27 being defined between the groove 43 and a surface of the adjacent second plate 33. It will be understood that, in embodiments, the grooves 43 may be defined by the second plates 33 such that the channels 27 are defined between the groove in a surface of the second plate and a surface of the first plate 31 that defines the fluid-containing cavity. In embodiments, the channels 27 may not be formed by grooves, and may instead be defined by bores that extend through the first plates 31 from the fluid-containing cavity to the outside edge 45 of the plate 31.

In embodiments, the first plates 31 may be configured such that the cavity 11 does not extend through the full depth of the plate 31 (such that it forms an aperture in the plate), but instead is defined by a recess in a surface of the plate. In such embodiments, the second plates 33 may be omitted, since the cavities 11 will be separated from each other by the first plates themselves.

A method 100 of manufacture of the component 1 will now be described, with reference to the flow chart of Figure 6. As a pre-cursor to the method 100 illustrated by Figure 6, the plurality of first plates 31 and plurality of second plates 33 must be formed. It will be understood that these plate formation steps may be considered to be steps of a method of manufacture of the component 1. The first plates 31 may be formed in any suitable way. For example, the first plates 31 may be cast, or each first plate 31 may be cut from a larger sheet of material and milled to form the cavity 11. The grooves 43 may be formed in any suitable way, for example using laser etching. In embodiments where the grooves 43 are replaced with bores that extend through the first plates 31, these bores may be formed in any suitable way, for example by drilling.

Likewise, the second plates 33 may be formed in any suitable way. For example, the second plates 33 may be cast, or each second plate 33 may be cut from a larger sheet of material.

The cavities 11 of the component 1 may be filled with fluids, which encompasses both liquids and gases. In the embodiment of the method 100 that is illustrated by the flow chart of Figure 6, the fluid-containing cavities are filled with liquid.

As discussed above, the Applicant has noted that liquid filled cavities suffer from the presence of bubbles inside the cavities, which can negatively impact the performance of the shockwave-manipulating volume 20. The method 100 is designed to reduce the presence of bubbles inside the component 1.

At step 101, the liquid for filling the fluid-containing cavities is de-gassed. By reducing the amount of gas that is dissolved in the liquid before the liquid enters the cavities, the presence of bubbles inside the cavities can be reduced. De-gassing the liquid can be performed using a number of techniques, which may be combined.

In embodiments, de-gassing the liquid may comprise placing a container of liquid inside a vacuum chamber held at low vacuum conditions (e.g. 5 mbar) for an extended period of time (e.g. 24 hours) in order to draw dissolved gas out of the liquid.

In embodiments, de-gassing the liquid may comprise ultrasonically de-gassing the liquid. During ultrasonic de-gassing, the liquid is subjected to sonic waves, which results in alternating high-pressure and low-pressure cycles. During low-pressure cycles, small vacuum bubbles or voids may be created in the liquid. Dissolved gas migrates into these vacuum bubbles via the large surface area of the bubbles and increases the size of the bubbles. The sonic waves additionally promote the coalescence of adjacent bubbles leading to an accelerated growth of the bubbles. These larger bubbles may then rise to the surface, releasing the gas from the liquid.

At step 103, the housing 5 and the plates 31, 33 are cleaned, e.g. using isopropyl alcohol. In embodiments, the cleaning may comprise a degreasing step. Imperfections, such as dust, on surfaces that are submerged in liquid may promote bubble formation on those imperfections. By cleaning the housing 5 and plates 31, 33, before assembly, imperfections can be removed. This may help to reduce bubble formation on the surfaces of the housing 5 and plates 31, 33.

At step 105, the cleaned housing 5 is placed into a bath of the de-gassed liquid.

At step 107, each plate is stacked one by one into the housing 5 inside the liquid bath. Referring to Figure 5, the first plate 31e would be placed into the housing 5 first, followed by the second plate 33, followed by the first plate 31d, etc.. The solid fill element 41 may be inserted into the cavity lla before the plate 31a is placed into the liquid bath.

In embodiments, the liquid bath is held under pressure whilst step 107 is performed.

As has been explained previously, holding liquids under pressure (for example 2 bar) may reduce the formation of bubbles by causing any gas that is dissolved in the liquid (i.e. which has not been removed by de-gassing step 105) to stay dissolved.

As such, it will be understood that once the component 1 is assembled, the fluid-containing cavities 11b, 11c, 1 1 d, le, the channels 27 and the ducts 7a, 7b will all be filled with the liquid from the liquid bath.

In embodiments, after the housing 5 and plates 31, 33 have been placed into the liquid bath, but before the plates 31, 33 have been stacked, the liquid bath may be subjected to ultrasonic cleaning. The sonic waves may help to displace any bubbles that may have formed on the surfaces of the housing 5 or the plates 31, 33.

At step 109, the assembled component 1 is removed from the liquid bath. In embodiments, blanks (e.g. bungs) may be inserted into the apertures 9a, 9b in order to prevent liquid escaping from the apertures 9a, 9b, e.g. before the assembled component 1 is removed from the liquid bath.

In embodiments, alignment structures (not shown) may be present on the surface of the plates 31, 33 and/or on the housing 5 to assist the correct alignment of the plates 31, 33, both with respect to each other and with the channels 27.

Filling the cavities with liquid in this way (as opposed to pumping liquid into an assembled component) may help to reduce the presence of bubbles inside the cavities since moving liquid is more prone to bubble formation. Further, the gas (e.g. air) that is present inside the cavities before the first plates 31 are placed into the liquid bath is easily displaced by the liquid. However, if liquid is pumped into an assembled component, the air inside the component must be pushed out through a complex path (e.g. via the channels 27 and the ducts 7a, 7b). In this situation, it is more likely that air will become trapped, resulting in bubbles.

In embodiments, the liquid may be water. De-ionised water may be used in order to reduce galvanic corrosion.

It will be understood that while the method 100 has been explained in relation to liquids, the method may be modified for cases where the cavity fill fluid is a gas, but the principle is the same, and assembling stacking the plates 31, 33 into the housing 5 within a gas-filled environment will result in the fluid-containing cavities 11b, 11c, 11d, 11e, the channels 27, and the ducts 7a, 7b, being filled with the gas from the gas filled environment.

In the embodiment of Figures 1 to 5, and the method 100 described in relation to Figure 6, each of the fluid-containing cavities is filled with the same fluid, and as will be seen, all of the fluid-containing cavities are fluidically connected. In embodiments however, it may be desirable to fill different fluid-containing cavities with different fluids. For example, it may be desirable for fluid-containing cavities to contain different liquids, different gases, or a combination of different liquids and gases.

Figure 7 shows a cut-away perspective view of a component 201, which is a variant of the component 1 shown in Figures 1 to 5. The construction and function of the component 201 is substantially the same as that of the component 1 discussed above and, unless stated otherwise, the component 201 shown in Figure 7 should be understood to be substantially the same as the component 1 shown in Figures 1 to 5.

In Figure 7, the component 201 defines five cavities 211a, 211b, 211c, 211d, 211e.

The upper cavity 211a partially defines the input face 210 of the component 201 and is a solid-containing cavity that is configured to contain a solid cavity fill material. The other cavities 211b, 211c, 211d, 211e are fluid-containing cavities that are configured to contain fluids. In an exemplary embodiment, the solid cavity fill material is polymethyl methacrylate (PMMA), but the solid cavity fill material could be any suitable material.

The two upper fluid-containing cavities 211b, 211c are configured to contain a first fluid, and the two lower fluid-containing cavities 211d, 211e are configured to contain a second fluid. As can be seen from a comparison of Figures 3 and 7, the construction of the body 3 of the component 1 shown in Figure 3, and the body 203 of the component 201 shown in Figure 7 is the same. As such, the details of the body 3 will not be described in detail here. However, the housing 205 of the variant component 201 shown in Figure 7 differs from the housing 5 of component 1 shown in Figure 3.

The housing 205 shown in Figure 7 defines four ducts, the first ducts 207a, 207b that are configured to be fluidically connected to the two upper fluid-containing cavities 211b, 211c, and the second ducts 217a, 217b that are configured to be fluidically connected to two lower fluid-containing cavities 211d, 211e. Each of the ducts 207a, 207b, 217a, 217b comprises a primary portion 29 (shown in Figure 8) and two conduits 28. The conduits 28 of the first ducts 207a, 207b each align with a respective channel 27 that is fluidically connected to one of the two upper fluid-containing cavities 211b, 211c respectively. The conduits 28 of the second ducts 217a, 217b each align with a respective channel 27 that is fluidically connected to one of the two lower fluid-containing cavities 211d, 211e.

The conduits 28 extend in a direction perpendicular to the longitudinal axis 15 (i.e. the conduits 28 extend in a direction parallel to (and are coaxial with) the direction in which the channels 27 extend). The conduits 28 are formed as cylindrical bores having a cross sectional area that is greater than the cross sectional area of the channels 27. The primary portions 29 extend in a direction parallel to the longitudinal axis 15 (i.e. the primary portions 29 extend in a direction perpendicular to the direction in which the channels 27, and conduits 28 extend). The primary portions 29 are formed as cylindrical bores having a cross sectional area that is greater than the cross sections area of the conduits 28.

The primary portions 29 of the ducts 207a, 207b, 217a, 217b extend to the input surface 210 of the component 1 and, as such, define apertures 209a, 209b, 219a, 219b in the input surface 210 of the component 1. Expansion chambers may be connected to the apertures 209a, 209b, 219a, 219b, as explained below in relation to Figure 8.

Although the embodiment of Figure 7 comprises a pair of first ducts 207a, 207b, and a pair of second ducts 217a, 217b, it will be understood that, in embodiments, only a single first duct, and a single second duct, may be provided.

Figure 8 shows a cross-sectional side view of the variant component 201 incorporated into a system 230. The system 230 is substantially similar to the system 30 described in relation to Figure 3, but comprises two sets of expansion -31 -tanks and expansion lines, in order to allow for the two different fluids which are present in the upper cavities 11b, 11c and the lower cavities 11d, 11e.

As such, the system 230 comprises a first expansion tank 235 that is fluidically connected to the upper fluid-containing cavities 211b, 211c that are configured to contain the first fluid, via the channels 27 and the first ducts 207a, 207b. The system 230 includes first expansion lines 237 that are connected to the apertures 209a, 209b defined by the primary portions 29 of the first ducts 207a, 207b.

The system 230 further comprises a second expansion tank 335 that is fluidically connected to the lower fluid-containing cavities 211d, 211e that are configured to contain the second fluid, via the channels 27 and the second ducts 217a, 217b. The system 230 includes second expansion lines 337 that are connected to the apertures 219a, 219b defined by the primary portions 29 of the second ducts 217a, 217b.

Like the system 30 of Figure 3, in the system 230 of Figure 8, the first and second expansion chambers 235, 335 each comprise a pressure inlet 39. After having been assembled, and filled with both the first and second liquids, the expansion chambers 235, 335 (and thus the fluid-containing cavities 211b, 211c, 211d, 211e) may be pressurised using a pressurising apparatus (not shown) connected to the pressure inlet 239. Holding liquids under pressure (for example 2 bar) may reduce the formation of bubbles by causing any gas that is dissolved in the liquid to stay dissolved.

In embodiments where different fluid-containing cavities contain different fluids, the method 100 may be adapted in order to manufacture such a component. A method of manufacturing the component 201 shown in Figure 7 will now be discussed, with reference to the method 100 discussed above. In the discussed embodiment, both the first and the second fluids are liquids, and so the de-gassing steps are performed for both the first and second fluids, which will hereinafter be referred to as the first and second liquids.

The de-gassing step 101 is performed on both the first and second liquids, the housing 205 and plates 31, 33 are cleaned according to step 103. At step 105, the housing is placed into a liquid bath containing the second liquid, and at step 107, the first plates 31e, 31d, and the two second plates 33 that are placed atop first plates 31e, 31d respectively are stacked into the cavity 205 inside the liquid bath containing the second liquid. The apertures 209a, 209n, and the conduits 28 of the first ducts 207a, 207b may then be blocked with blanks (e.g. bungs) prior to the housing 205 being placed into the liquid bath, in order to prevent the second liquid entering the first ducts 207a, 207b. As such, when the partially assembled component 201 is removed from the liquid bath, the two lower fluid-containing cavities 211d, 211e are both filled with the second liquid.

The method then reverts to step 105 and the partially assembled component 201 is placed into a liquid bath containing the first fluid. The apertures 219a, 219b will need to be blocked with blanks (e.g. bungs) in order to prevent the first liquid entering the second ducts 217a, 217b. At step 107, the remainder of the plates are stacked into the housing 205 inside the liquid bath such that when the component 201 is removed from the liquid bath at step 109, the two upper fluid-containing cavities 211b, 211c are filled with the first liquid.

Figure 9 shows a cross-section through a component 301 which is a variant of component 1 described in relation to Figures 1 to 4. The construction and function of the component 301 is substantially the same as that of the component 1 discussed above and, unless stated otherwise, the component 301 shown in Figure 9 should be understood to be substantially the same as the component 1 shown in Figures 1 to 5.

In the component 301, the plurality of thin high shock-impedance layers 319 are curved (e.g. domed) such that the cavities 311 are also curved in shape. The curved layers may help to focus (e.g. spherically focus) an input shockwave. The presence of cavities having more complex shapes may encourage the formation of bubbles, since air may be more likely to become trapped in tight corners, or on edges. As such, as more complex cavity shapes are used, the invention (in particular the novel method of manufacture) described herein may have increased impact.

It will be understood that any embodiments described herein which are compatible with component 1 may also be applied to component 301. For example, component 301 could also have separate ducts such that the fluid-containing cavities can contain different fluids (e.g. four ducts as shown in component 201 of Figure 7).

Claims (25)

1. Claims 1. A component for manipulating an input shockwave to produce localised energy concentrations, wherein the component comprises: a body comprising a first material; one or more cavities defined within the body, wherein the one or more cavities is configured to manipulate the input shockwave so as to produce a manipulated shockwave; wherein at least one of the one or more cavities comprises a cavity for containing fluid; wherein the body defines a channel extending from the cavity for containing fluid through the first material; wherein the channel is configured to fluidically connect the cavity for containing fluid to a further volume.
2. 2. The component as claimed in claim 1, wherein the body comprises a plurality of stacked plates; wherein the plurality of stacked plates comprises one or more first plates; wherein each of the first plates defines one of the one or more cavities.
3. 3. The component as claimed in claim 2, wherein one or more of the first plates comprises a recess defining the cavity.
4. 4. The component as claimed in claim 2 or 3, wherein the plurality of plates comprises one or more second plates; and wherein the one or more second plates do not define a cavity.
5. 5. The component as claimed in claim 4, wherein one or more of the first plates comprise an aperture defining the cavity; and wherein one or more of the second plates are arranged adjacent the one or more of the first plates.
6. 6. The component as claimed in any one of the preceding claims, wherein the channel is configured to fluidically connect the at least one cavity for containing fluid to an expansion chamber.
7. 7. The component as claimed in any one of the preceding claims, comprising a plurality of cavities defined within the body.
8. 8. The component as claimed in claim 7, wherein at least two of the plurality of cavities are cavities for containing a fluid.
9. 9. The component as claimed in claim 8, wherein the channel is configured to fluidically connect the at least two cavities for containing fluid.
10. 10. The component as claimed in claim 8 or 9, wherein the at least two cavities for containing fluid are arranged to contain different fluids.
11. 11. The component as claimed in claim 8, 9 or 10, wherein the body defines a channel for each of the cavities for containing fluid; and wherein the channels are configured to fluidically connect the cavities for containing fluid to different expansion chambers.
12. 12. The component as claimed in any one of the preceding claims, wherein the body defines one or more channels extending from each cavity for containing fluid through the first material to an outside edge of the body; and wherein each cavity for containing fluid is arranged to be fluidically connected to a further volume via the one or more channels.
13. 13. The component as claimed in any one of the preceding claims, wherein the body comprises a plurality of stacked plates; wherein the plurality of stacked plates comprises one or more first plates; wherein each of the first plates defines one of the one or more cavities; wherein one or more of the plurality of plates comprises one or more grooves in a surface of the plate; wherein the one or more channels are defined by the one or more grooves and a surface of an adjacent plate of the plurality of stacked plates.
14. 14. The component as claimed in any one of the preceding claims, wherein the component comprises a housing within which the body is at least partially received.
15. 15. The component as claimed in claim 14, wherein the body comprises a plurality of stacked plates; wherein the plurality of stacked plates comprises one or more first plates; wherein each of the first plates defines a cavity; wherein the housing is configured to maintain the alignment of the plurality of plates when the body is at least partially received within the housing.
16. 16. The component as claimed in claim 14 or 15, wherein the housing defines one or more ducts that are fluidically connected to the channel such that each cavity for containing fluid can be fluidically connected to an expansion chamber and/or to another cavity for containing fluid via the channel and one or more of the ducts.
17. 17. The component as claimed in 16, wherein the component comprises at least two cavities for containing fluid, and wherein the channels extending from the at least two cavities are fluidically connected to a common duct, such that the at least two cavities are fluidically connected via the common duct.
18. 18. The component as claimed in any one of the preceding claims, wherein at least one cavity for containing fluid contains a liquid.
19. 19. A system comprising: a component as claimed in any one of the preceding claims; and an expansion chamber fluidically connected to the at least one cavity for containing fluid.
20. 20. A method of manufacturing a component for manipulating an input shockwave to produce localised energy concentrations; wherein the component comprises the component as claimed in any one of claims 1 to 18; wherein the body of the component comprises a plurality of stacked plates; wherein the plurality of stacked plates comprises one or more first plates; wherein each of the first plates defines a cavity for containing fluid; wherein the method comprises: stacking the plurality of plates, wherein at least one of the first plates and at least another of the plurality of plates are brought together in a fluid-filled environment, such that the cavity for containing fluid defined by the at least one of the first plates contains the fluid from the fluid-filled environment.
21. 21. A method of manufacturing a component for manipulating an input shockwave to produce localised energy concentrations, wherein the component comprises: a body comprising a first material; a one or more cavities defined within the body, wherein the one or more cavities is configured to manipulate the input shockwave so as to produce a manipulated shockwave; wherein at least one of the one or more cavities comprises a cavity for containing fluid; wherein the body comprises a plurality of stacked plates; wherein the plurality of stacked plates comprises one or more first plates; wherein each of the first plates defines a cavity for containing fluid; and wherein the method comprises: stacking the plurality of plates, wherein at least one of the first plates, and at least another of the plurality of plates are brought together in a fluid-filled environment such that the cavity defined by the at least one of the first plates contains the fluid from the fluid filled environment.
22. 22. The method as claimed in claim 20 or 21, wherein the component comprises a housing within which the body is at least partially received; wherein the method comprises stacking the plurality of plates into the housing; wherein the housing is configured to align the plurality of plates.
23. 23. The method as claimed in claim 20, 21 or 22, wherein the fluid of the fluid-filled environment is a liquid; and wherein placing the at least one of the first plates in a fluid-filled environment comprises submerging the at least one of the first plates in a liquid bath.
24. 24. The method as claimed in claim 23, comprising de-gassing the liquid before the at least one of the first plates is submerged in the liquid bath.
25. 25. A method of using the system of claim 19, comprising pressurising the expansion chamber so as to apply pressure to the at least one cavity for containing fluid.