CN116105960A - Free piston shock tunnel with distributed counterweight system - Google Patents

Abstract

The invention provides a free piston shock tunnel with a distributed counterweight system, which comprises a tunnel body and a distributed counterweight block arranged on the tunnel body, wherein the tunnel body is arranged on a track, a lockable pulley is arranged between the distributed counterweight block and the track, and a tunnel operation monitoring system is arranged near the distributed counterweight block. The distributed balancing weights are arranged on the wind tunnel body, so that the wind tunnel body can be increased and reduced, and is convenient to install and adjust; the distributed balancing weights are beneficial to stable axial movement of the hole body on the track, so that derailment risk is reduced; the strain monitoring module can effectively collect stress data of the wind tunnel structure, and the high-speed camera can collect speed and displacement data, so that the safety of the wind tunnel is guaranteed, and data analysis and dynamic optimization are facilitated.

Description

A Free Piston Shock Tunnel with Distributed Weight System

technical field

The invention relates to the technical field of wind tunnel structure, in particular to a free piston shock wave wind tunnel with a distributed counterweight system.

Background technique

The shock wave wind tunnel uses the high-temperature and high-pressure test airflow generated after the incident shock wave is reflected upstream of the nozzle to conduct experiments. If a high-enthalpy shock tunnel with high-performance drive is used, the simulated flight speed can reach up to 7km/s. Using advanced modern testing instruments and related testing techniques, the effective time is within the range of a few milliseconds, and it has been able to meet the research on complex gas physics and other issues under ultra-high speed conditions. In principle, the high-enthalpy shock tunnel can reproduce the flight environment of a hypersonic vehicle, and can simulate the velocity, pressure and temperature conditions of the gas in the flight environment. From the perspective of engineering applications, the high-enthalpy shock tunnel can carry out research on aerothermal/mechanical, scram propulsion, free flight, stage separation, radiation characteristics, photoelectric characteristics and electromagnetic scattering. Based on the above two aspects, the high-enthalpy shock tunnel has the most direct application in the research on the mechanism of high-temperature gas effects and in the design of hypervehicles.

The total temperature and total pressure level of the high-enthalpy shock tunnel nozzle is determined by the drive technology of the wind tunnel. High-efficiency drive technologies mainly include technologies such as variable cross-section, multi-stage, light gas and heated light gas. The effective combination of the above-mentioned different driving technologies can effectively increase the intensity of the incident shock wave, thereby obtaining higher total enthalpy and total pressure. Using light gas and heating light gas (electric heating, detonation heating and free piston compression heating, etc.). The free piston shock tunnel can obtain the maximum performance and operational flexibility, but the technical risk is relatively complex.

During the operation of the free piston shock wave wind tunnel, when the high-pressure driving gas drives the piston to hit the brake mechanism and stop, an axial impact load is generated on the wind tunnel body; after the driven gas flows through the profile nozzle to establish a test flow field, the wind tunnel The tunnel body produces axial load, and the superposition of the two loads will cause a large displacement of the wind tunnel and damage the wind tunnel body. The friction generated by the gravity of the wind tunnel alone is not enough to protect the tunnel structure. Therefore, it is necessary to increase the counterweight structure or increase the friction of the track to reduce the displacement of the wind tunnel under load. At present, the commonly used counterweight structure is generally a counterweight concentrated in one area. This method requires high local strength of the structure, which makes the mechanism large in size and difficult to move during the test preparation process. Once a problem occurs, it is very difficult. It is difficult to adjust, so a more elaborate distributed weight and optimization system needs to be designed to solve these problems.

Contents of the invention

The object of the present invention is to provide a free-piston shock wave tunnel with a distributed counterweight system. The use of distributed counterweights helps the stable axial movement of the tunnel body on the track and reduces the risk of derailment.

According to an object of the present invention, the present invention provides a free piston shock wave wind tunnel with a distributed counterweight system, comprising a wind tunnel body and distributed counterweights arranged on the wind tunnel body, the wind tunnel body It is arranged on a track, a lockable pulley is installed between the distributed counterweight and the track, and a wind tunnel operation monitoring system is installed near the distributed counterweight.

Further, the wind tunnel body includes a high-pressure gas storage chamber, a compression tube, a compression tube bracket, a large clamping mechanism, a shock tube, a small clamping mechanism, a nozzle, an angle of attack mechanism and a test section connected in sequence. A floating and reset mechanism is provided at the bottom of the angle of attack mechanism, and a shock tube bracket is provided below the shock tube.

Further, the lockable pulley is locked during the blowing process, which can change rolling friction into sliding friction, and the friction coefficient increases from 0.005 to 0.17.

Further, the mass of the distributed counterweight is calculated by the following dynamic formula:

F ₁ t = MV = m _p v (2)

In the above formula, F ₁ is the force received during the operation of the wind tunnel; M is the mass of the wind tunnel; V is the speed of the wind tunnel; S is the movement displacement of the wind tunnel; v is the piston running speed; F ₂ is the wind tunnel The force received by the movement; P _R , P _C are the pressures of the high-pressure air storage chamber and the compression tube respectively; f is the friction force between the piston and the compression tube during the movement.

Further, the wind tunnel operation monitoring system monitors the stress state of the wind tunnel structure in real time, and dynamically adjusts the wind tunnel counterweight.

Further, the wind tunnel operation monitoring system uses a high-speed camera to collect the displacement of the tunnel body and draws a curve to analyze the actual velocity and displacement of the tunnel body when it is subjected to impact load.

Further, the acquisition frequency of the wind tunnel operation monitoring system is greater than 10kHz.

Further, the distributed counterweight is arranged on the high-pressure gas storage chamber, the compression tube, the large clamping mechanism, the shock tube, the small clamping mechanism or the nozzle.

Further, the overall mass of the counterweight installed on the compression tube is 180t-220t, and the overall mass of the counterweight installed on the shock tube is 80t-100t.

Further, the distributed counterweights include a plurality of counterweights assembled and integrated, each of which has a mass of 12t.

In the technical solution of the present invention, distributed counterweights are arranged on the wind tunnel body, which can be moved, increased or decreased, which is convenient for installation and adjustment; the distributed counterweights help the tunnel body to move stably on the track in the axial direction and reduce derailment Risk; the strain monitoring module can effectively collect the force data of the wind tunnel structure, and the high-speed camera can collect speed and displacement data, which is not only conducive to ensuring the safety of the wind tunnel, but also convenient for data analysis and dynamic optimization.

Description of drawings

In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the specific implementation or description of the prior art. Obviously, the accompanying drawings in the following description The drawings show some implementations of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

Fig. 1 is the structural representation of the embodiment of the present invention;

Fig. 2 is a schematic structural diagram of a distributed counterweight according to an embodiment of the present invention;

Fig. 3 is the sectional view of A-A in Fig. 2 of the embodiment of the present invention;

In the figure, 1. High-pressure gas storage chamber; 2. Compression tube; 3. Compression tube support; 4. Large clamping mechanism; 5. Shock tube; 6. Small clamping mechanism; 7. Nozzle; 8. Angle of attack Mechanism; 9. Test section; 10. Floating and reset mechanism; 11. Shock tube bracket; 12. Track; 13. Distributed counterweight; 14. Wind tunnel operation monitoring system.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In describing the present invention, it is to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", etc. or The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of said features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined. In addition, the terms "installation", "connection" and "connection" should be interpreted in a broad sense, for example, it can be fixed connection, detachable connection, or integral connection; it can be mechanical connection or electrical connection; it can be It can be directly connected, or indirectly connected through an intermediary, and can be internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

Example 1

As shown in Figure 1-Figure 3,

A free piston shock wave wind tunnel with a distributed counterweight system, comprising a wind tunnel body and distributed counterweights arranged on the wind tunnel body, the wind tunnel body is arranged on a track 12, and the wind tunnel body includes sequentially connected High-pressure gas storage chamber 1, compression tube 2, compression tube bracket 3, large clamping mechanism 4, shock tube 5, small clamping mechanism 6, nozzle 7, angle of attack mechanism 8 and test section 9, angle of attack mechanism 8 The bottom of the bottom is provided with a floating and reset mechanism 10, and the bottom of the shock tube 5 is provided with a shock tube bracket 11, a high-pressure gas storage chamber 1, a compression tube 2, a compression tube bracket 3, a large clamping mechanism 4, and a small clamping mechanism 6 , the nozzle 7 and the shock tube support 11 are all arranged on the track 12 .

A lockable pulley is installed between the distributed weight 13 and the track 12, and a lockable pulley is installed between the distributed weight 13 and the track 12, which can be locked during the blowing process, and the rolling friction can be changed into sliding friction, and the friction coefficient is from 0.005 Increasing to 0.17, the friction increases accordingly.

The counterweight is a distributed counterweight, and the installation position and quality of the counterweight are determined according to the foundation of the wind tunnel workshop, the capacity of the crane in the workshop, and the stress conditions of the wind tunnel operation. The counterweight is a modular structure, which can facilitate assembly and increase the quality of the overall counterweight.

A wind tunnel operation monitoring system 14 is installed near the distributed counterweight 13 to monitor the stress state of the wind tunnel structure in real time, and dynamically adjust the wind tunnel counterweight to make it evenly stressed and avoid structural damage. Under the condition of increasing the total pressure of the wind tunnel during debugging, the movement displacement of the wind tunnel is close to the design state of the wind tunnel, and the mass of the counterweight is increased. Use a high-speed camera to collect the displacement of the cave body and draw a curve to analyze the actual velocity and displacement of the cave body under impact load.

During high total pressure operation, the wind tunnel operation monitoring system 14 is used to collect the displacement of the tunnel body and draw a curve to analyze the actual velocity and displacement of the tunnel body under impact load. The collection frequency of the wind tunnel operation monitoring system 14 is greater than 10 kHz.

The distributed counterweight 13 can be installed on the high-pressure gas storage chamber 1, the compression tube 2, the large clamping mechanism 4, the shock tube 5, the small clamping mechanism 6 and the nozzle 7, and the wind tunnel can be increased in the way of distributed counterweight The overall quality reduces displacement during wind tunnel operation.

During high total pressure operation, the overall mass of the counterweight installed on the compression tube 2 is 180t-220t, and the overall mass of the counterweight installed on the shock tube 5 is 80t-100t. The distributed counterweights 13 can be freely assembled and integrated, and each counterweight has a mass of about 12t, which satisfies the operating conditions of the rail 12, the compression tube support 3 and the shock tube support 11.

When running at high total pressure, the wind tunnel body needs to add counterweights, and the mass of the counterweights is calculated by the following dynamic formula:

F ₁ t = MV = m _p v (2)

In the above formula, F ₁ is the force received during the operation of the wind tunnel; M is the mass of the wind tunnel; V is the speed of the wind tunnel; S is the movement displacement of the wind tunnel; v is the piston running speed; F ₂ is the wind tunnel The force received by the movement; P _R , P _C are the pressures of the high-pressure air storage chamber and the compression tube respectively; f is the friction force between the piston and the compression tube during the movement.

After dynamic calculation, when the total pressure of the wind tunnel nozzle exceeds 160MPa, in order to ensure that the overall displacement of the wind tunnel body is less than 50mm, the overall mass of the counterweight needs to exceed 240t, and the counterweight adopts a modular and integrated design .

When the present invention is used, the operation steps are as follows:

(1) Install about 20 counterweights on the compression tube bracket 3 and the shock tube bracket 11, and loosen the locking mechanism of the bottom pulley to open the strain module acquisition system;

(2) Preparing for the test according to the conventional steps, specifically including the process of film clipping and inflation;

(3) Lock the pulley, carry out the test, and collect the strain data of the wind tunnel structure and the displacement and velocity data of the tunnel body at the same time;

(4) Analyze the data and perform reasonable optimization within the safe position range.

In the present invention, distributed counterweights are arranged on the wind tunnel body, and the distributed counterweights adopt a modular design, which can be moved, increased or decreased, and are convenient for installation and adjustment; the distributed counterweights help the tunnel body on the track The stable axial movement reduces the risk of derailment; after the counterweight pulley is locked, the rolling friction can be changed into sliding friction, effectively increasing the friction; the strain monitoring module can effectively collect the force data of the wind tunnel structure, and the high-speed camera can collect speed and displacement The data is not only conducive to ensuring the safety of the wind tunnel, but also convenient for data analysis and dynamic optimization.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (10)

1. A free piston shock wave wind tunnel with a distributed counterweight system, characterized in that it comprises a wind tunnel body and a distributed counterweight arranged on the wind tunnel body, and the wind tunnel body is arranged on the track A lockable pulley is installed between the distributed counterweight and the track, and a wind tunnel operation monitoring system is installed near the distributed counterweight. 2. The free piston shock wave tunnel with distributed counterweight system according to claim 1, characterized in that, the wind tunnel body includes a high-pressure gas storage chamber, a compression tube, a compression tube bracket, a large Clamping mechanism, shock tube, small clamping mechanism, nozzle, angle of attack mechanism and test section, the bottom of the angle of attack mechanism is provided with a floating and reset mechanism, and the bottom of the shock tube is provided with a shock tube bracket . 3. The free-piston shock wave tunnel with a distributed counterweight system according to claim 1, characterized in that, the lockable pulley is locked during the blowing process, so that rolling friction can be changed into sliding friction, and the friction coefficient is Increased from 0.005 to 0.17. 4. The free-piston shock tunnel with distributed counterweight system according to claim 1, wherein the mass of the distributed counterweight is calculated by the following dynamic formula:

F ₁ t = MV = m _p v (2)

In the above formula, F ₁ is the force received during the operation of the wind tunnel; M is the mass of the wind tunnel; V is the speed of the wind tunnel; S is the movement displacement of the wind tunnel; v is the piston running speed; F ₂ is the wind tunnel The force received by the movement; P _R , P _C are the pressures of the high-pressure air storage chamber and the compression tube respectively; f is the friction force between the piston and the compression tube during the movement. 5. The free-piston shock wave tunnel with distributed counterweight system according to claim 1, characterized in that, the wind tunnel operation monitoring system monitors the stressed state of the wind tunnel structure in real time, and carries out the wind tunnel counterweight Dynamic Adjustment. 6. The free-piston shock tunnel with distributed counterweight system according to claim 5, characterized in that, the wind tunnel operation monitoring system adopts a high-speed camera to collect the displacement of the tunnel body and draw a curve, and analyze the displacement of the tunnel body in Actual velocity and displacement when subjected to shock loads. 7. The free-piston shock tunnel with distributed counterweight system according to claim 6, characterized in that, the acquisition frequency of the wind tunnel operation monitoring system is greater than 10 kHz. 8. The free-piston shock tunnel with a distributed counterweight system according to claim 2, wherein the distributed counterweights are arranged in the high-pressure gas storage chamber, the compression tube, the on the large clamping mechanism, the shock tube, the small clamping mechanism or the nozzle. 9. The free piston shock wave tunnel with a distributed counterweight system according to claim 8, characterized in that, the overall mass of the counterweight installed on the compression tube is 180t-220t, and the shock tube is The overall quality of the installed counterweight is 80t-100t. 10. The free-piston shock tunnel with a distributed counterweight system according to claim 1, wherein the distributed counterweights comprise a plurality of counterweights assembled and integrated, and each of the counterweights Block mass is 12t.

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