RU1809390C - Method of determination of average parameters of vertical structure of field of flow from vessel - Google Patents

Abstract

Usage: determination of average parameters of currents in water bodies. SUMMARY OF THE INVENTION: successive cycles of immersion to a given depth and ascent to the initial level of the measuring line are performed, during each dive and ascent, components of the relative flow velocity vectors are measured, which makes it possible to determine the parameters of the vertical structure of the flow velocity field averaged over a known spatial time scale. 2 ill.

Description

The invention relates to measuring technique and can be used to determine average flow parameters in water bodies.

The aim of the invention is to simplify and expand the operational capabilities of the method for determining the average parameters of the vertical structure of the flow field from a ship.

This goal is achieved in that c. vessels lower the measuring line to the initial horizon, including a cable or a load-carrying cable with a device fixed therein for measuring the average speed and direction of the incoming flow, and carry out successive cycles of immersion at a given horizon and lifting to the initial horizon of the measuring line. The initial horizon is selected extremely close to the carrier vessel, taking into account the draft of the vessel and its speed and can be, for example, equal to

doubled draft; the lower (predetermined) horizon is determined by the task and measurement conditions. During the sensing cycle, measurements are made of the parameters of the airflow velocity vector and the parameters of the velocity sector of the carrier vessel (e.g., the coordinates of the beginning and end of the measurement cycle). At the same time, there are no special restrictions on the mode of movement of the carrier vessel, however, it is methodologically advisable to maintain a constant mode of movement of the vessel and constant modes of winding and selecting a measuring line during one measurement cycle to increase the accuracy of the results.

In order to improve the resolution and increase the reliability of the obtained results, the location of the relative velocity vector parameter meter can be monitored

00

u s u

about

currents. To this end, during the sensing cycle, measurements are additionally made of the immersion depth of the meter and / or the orientation of known sections of the measuring line and the length of its wound portion.

In FIG. 1 shows a measuring system for implementing the method in a coordinate system moving progressively with a ship; in FIG. 2 - the same in the geographical coordinate system.

The load-carrying cable or cable 1 enters the measuring system, on which the measuring instrument 2 of the parameters of the free-stream velocity vector is attached. The measuring system can be supplemented by a depth sensor for measuring the location of meter 2, a measuring instrument for the orientation of the root end and a measuring instrument for the coiled part of the measuring line in order to further control the location of the measuring device 2. An additional ballast or measuring line depth can be included in the measuring system.

Known sensors of similar purpose can be used as a measuring instrument 2 for the parameters of the velocity vector of the incoming flow. As additional means for controlling the location of the meter 2, known pressure sensors, physical or gyro-verticals, magnetic compasses or gyro compasses, and block-counters can be used. Measurement of the parameters of the vessel’s movement (coordinates of the beginning and end of the measurement cycle, and (or) the module and the direction of its velocity vector during measurements) is carried out using navigation equipment available on the carrier vessel.

The method for determining the average parameters of the vertical structure of the flow field from the vessel is as follows.

In a given area of the water area, the measuring line 1 is lowered from the vessel with the meter 2 installed on it and the relative flow velocity to the initial depth equal to, for example, doubled draft of the vessel, and then the measuring line is etched until the meter 2 reaches the specified depth. The depth can be determined directly. by determining the hydrostatic pressure, or analytically, by geometrically reconstructing the measurement line configuration in three-dimensional space from the orientation data parts, for example, its root and running ends, and the length of its coiled part. After the end of the dive, the rise of the measuring line to the initial horizon begins. Free flow velocity is measured by immersion and by raising the measuring line; parameters are determined for the same period

the movement of the ship. The vector sum of the URdu data averaged over the full cycle (descent and ascent) of the meter 2 and the VPS speed data of the carrier vessel determines the desired average speed UAdu of the true (absolute) current in the depth range covered by the measurements:

fifteen

UAdU URdU + VPS.

(1)

To assess the horizontal spatial scale of the path of the movement of the measuring instrument 2 from the obtained data, the parameters of the vector of the average drift velocity of the measuring instrument 2 from the vessel in a given depth range during immersion can be determined 2Q:

25VsMdW URdu URdw (2) and while lifting:

-at

thirty

VsMUP .URdU - URUP.

(3)

where: VsMdw-VSMUP are the mean transport vectors of the meter relative to the vessel during immersion and lifting, respectively;

URdW URUP are the average relative velocity vectors recorded during the dive and rise times, respectively.

Similar estimates of the vectors VSM (H, t),

where h is the depth, t is the time, can be obtained using data on the orientation of known sections of the measuring line and the length of its coiled part. The average characteristics thus obtained

the speed of the measuring line relative to the vessel during the measurement cycle allows you to supplement the data received from the meter 2, to clarify the parameters of the drift velocity vectors of the measuring line at scales smaller than the measurement cycle, and, as a result, determine the current (inside the measurement cycle) variability of the average vertical parameters field-flow structures at known spatiotemporal boundaries.

The proposed method has the following advantages. The implementation of the method is possible both from a ship lying in a drift, or standing on a bark, and from a ship moving actively, without the need for the ship to perform special maneuvers. In this case, it is possible to use both standalone relative flow rate meters that store recorded data on the internal storage device, and meters that transmit recorded information on board the carrier vessel via a load-carrying cable or sonar channel. When implementing the method, a metrologically secured correct estimate of the average parameters of the vertical structure is obtained, the field of the current velocity, determined by the set of points of the sounding path; in this case, the metrological assurance is due to the possibility of correct metrological certification of the used flow velocity meter by standard methods. In the implementation of the method, there is no need to equip the carrier vessel with special equipment for preparing, deploying and operating the measuring line, as well as for controlling the measuring element, as a result, the implementation of the method by specialized qualified personnel is simplified and, at the same time, the task of automating measurements is simplified. To implement the method, it is sufficient to use standard lifting equipment (cable and cable-cable winches) available on ships, including those not intended for scientific research purposes, thereby expanding the possibilities of applying the method by performing incidental measurements.

Claims (2)

1. A method for determining the average parameters of a vertical structure from a ship, which consists in immersing a measuring line mounted on it at a predetermined depth, measuring the parameters of the relative velocity vector and the velocity vector 0 of the vessel, as well as the control of the immersion depth of the measuring line, its orientation and length, which are also distinguished by the fact that, in order to simplify the method and expand its operational capabilities, 5 consecutive cycles of diving to a given depth and lifting to the initial level of the measuring line, the parameters of the relative current velocity vector are measured during each dive and From the elevation and the vectors averaged over the full cycle, the relative current velocity and the vessel speed determine the average current velocity in a given layer. 2. The method according to claim 1, characterized in that, in order to improve its resolution and increase the reliability of the measurement results, according to the parameters of the relative velocity vector measured during immersion and raising of the measuring line, as well as by the depth of immersion of the measuring line and its orientation and length, the horizontal spatial scale of the measuring path of the gauge is estimated by determining the average characteristics of the motion of the measuring line relative to the vessel during the measurement cycle. / 7 / AA I V FIG. 7