SU1278728A1 - Device for measuring three-dimensional distribution of components of velocities of liquid flow - Google Patents

Abstract

The invention can be used for volumetric measurements of the three component flow rates and allows for expanding the functionality of the device. When a video pulse starts, one of the tracks from the camera 6 switches over the counter 19, which selects the next storage register of the storage device 22, the video pulse is fed to the delay circuit 15, the driver 16 and the measuring unit 8 where the coordinates are measured in the longitudinal meter 9 and the transverse IO coordinate the beginning of the track, in the meter And the amplitude of the video signal - the amplitude of the video impulse, and in block 12 - the area of the S path segment between the lines of the scan. Diagram 32 of the track intersection analyzer is given and its operation is described. 1 hp f-ly, 5 ill.

Description

The invention relates to a technique for measuring the velocity characteristics of fluid flows by a non-contact method and can be used for volumetric measurements of the three components of the flow velocities. The aim of the invention is to enhance the functionality of the device by measuring the volume distribution of the three components of the velocity vector of the fluid flow. The measurement of the component flow rates of the fluid is carried out as follows. When the test area is examined by radiation partially absorbed by the liquid, the illumination of particles E within the investigated volume is determined by the Bouguer – Lambert law: Е Е Е „Егде Ер - illumination at the boundary and the volume to be traced; U is the linear light absorption coefficient; y is the thickness of the fluid layer. Finding vdaes in a stream of spherically zero-buoyancy particles scatter light in all directions. The intensity of the scattered light is also ignored by the Bouguer law, and the variation in illumination with depth y occurs according to the law E a (2). The intensity of the scattered light on the chip along the registration axis is determined by the extrusion:, E,; e- (3) where K is the coefficient depending on the distance of the light on the part. Hence, the illumination on the target of the tube is, (О where K "is constant , determined by the distance to the target and terms in optics, the depth of the potential relief on the target Uj on the linear section of the accumulation curve is E2t,, (5) where K is the sensitivity of the photo layer; - exposure. In addition, the depth of the potential relief depends on particle velocity. The depth of the relief at all points potentially image and track uniformly decreases in proportion to the decrease in accumulation time at each point and and Z 7.0 Y where and is the relief depth for the fixed particle, d is the particle diameter, 2 is the length of the track in the plane Amplitude of the read video signal is equal, {7) where Ku coefficient of proportionality between the amplitude of the video signal and the depth of the potential relief. Considering the above:. .) where, - K.. Therefore, the coordinates of the ends of the track Z, Z are determined by the expressions -. - (in) l: llAii) | 9r K-CY.i in Ji-L) - (Y ,. .linY | -l) .. c, ... , 1, VK (X, -XH) + (Y, -YH) + - Xn ----, where X, Уц, Хц, У | - coordinates of the beginning and end of the track in the coordinate system of the HOU; S is the area of the track, V, V is the amplitude of the read signal of the beginning and end of the track. The value of K can be found by measuring the amplitude of the video signal from a particle at a known point of the volume under investigation. The coordinates of the ends of the track Hz, XX, YH, YK are determined by the time position of the last last video pulse of the track relative to the sync pulses of the camera:, Xj, MV "t ,; ,,,, ,, t. ,,; where M is the scale of the image j Vpx.Vp.i the speed of the longitudinal and transverse scanning; the time interval between the first (last) video pulse from the track and the sync signal of the longitudinal scan; and chto, relative to the sync signal of the transverse scan. The longitudinal and transverse V and normal V7p components of the flow velocity are equal to: tt V liil IJ -. “(In i. In YH y t, ut 1 V, Coordinates of a point in the studied volume of fluid, for which the velocity components and ", Vj, W, equal to XH + XJ (, YH + Y." ZH + ZK, "l- -2 -5- -5 - AND Splitting the tracks of individual particles is performed by switching the track counter when the video pulse of the beginning of the track arrives , transferring the output code of this counter to the address inputs of the memory device of the track parameters, recording the measured parameters of the video pulses into this device, writing the output code of the track counter in one and two memory devices track numbers, recording and reading of which is performed alternately on adjacent scan lines, with the sequential switching of memory registers during recording and reading performed by video pulses of tracks on the current and previous lines, and the reappearance of the re-impulse video track and the rewriting of the code of the track number to the second storage device of new-meiJoB tracks. calling the well-known principle of delayed coincidences. The process of rewriting the track number continues until the end of the sweep of its image. In FIG. Figure 1 shows the optical layout of the device; fig.2 is an electrical circuit of the device; in fig. 3 is a diagram of a track intersection analyzer made in accordance with the second claim of the invention; in fig. 4 - tracks in the raster; in fig. 5 is a timing diagram of the operation of the track intersection detection circuit. The proposed device contains a source of light 1 that forms a uniform parallel beam of light, the spectral composition of which is selected from the condition of partial absorption in a liquid, a diaphragm 2 providing illumination of the investigated volume 3 of liquid through the transparent wall of the hydrochannel 4 or the free surface of the stream visualized by suspended particles 5, non-interlaced image television camera 6, converting optical image of the investigated volume into an electrical video signal depending on the type of light source 1 (continuous or pulsed) the continuous light flux interrupter or the trigger unit of the pulsed light source. The measuring unit 8, which includes the longitudinal 9 and transverse 10 coordinate meters, the video signal amplitude meter 11, the track area meter 12 between the scan lines, the scaling unit 13, which develops the pulse sequences synchronized with the scan frequency of the telecamera 6, the frequency of which is selected from the condition of measuring coordinates and amplitudes video pulses as well as areas of track elements in blocks 9-12 in received units, and summing unit 14, delay circuit 15 for the horizontal scanning period, driver 1 6 pulses, track splitting unit 17, including digital video pulse counters on the previous I8 and current 19 scan lines, 20 track counters, storage devices 21 22 track numbers, switch 23 address inputs memorize 1 silent devices 21 and 22, switches 2A and 25 write inputs storing the devices 21 and 22, respectively, the switch 26 of the read outputs of the memory devices 21 and 22, the switch 27 of the address inputs memorizing; its device of the track parameters, the storage device 28 of the track parameters, each storing The first register of which includes three segments and a check bit, while the first segment is intended for storing the coordinates and amplitudes of the video signal of the beginning of a track, the second segment is the coordinates and amplitudes of the video signal of the end of the track, the third segment of the area code, and the check bit for recording the sign of the intersection of tracks, the switch 29 of the recording entries of the storage device 28, the functional block 30, the block 31 of registration and analysis of the op 32 intersection of tracks containing the raster border signal generator 33, signal formers 34 and 35, Embedded with the beginning and cone of the video impulse of the track, the formers 36 and 37 signals coinciding with the beginning and the end view, its impulse for the track delayed by the row duration, the coincidence circuit, the RS-triggers 43 45, the formers 46 pulses and the logical circuit OR 47. The device works as follows. The light source and the camera 6 are set so that their optical axes are mutually perpendicular, and the focal length of the optical system of the camera 6 and the distance to the liquid 3 of the sample are chosen based on the condition that the reflected light reflected from the particles 5 and the perspective distortions within volume 3. When an external signal is received, the Start and the signal from the scaler unit 7 provide short-term exposure of the accumulative target of the transmitting tube of the camera 6, after which it is produced roechnoe deployment obtained image. The sync pulse of the first scan line, fed from the clock generator 6 camera output, sets the counters 18 k 19 to the initial position, switches the switch 23 so that the code outputs of the counters 8 6 and 18 and 19 through the switch 23 are connected to the address inputs of the memory devices 22 and 21, respectively, switches the switch 26, which connects the readout outputs of the storage device 22 through the open in the absence of a control signal from the driver 16 of the switch 27 to the address inputs of the storage device 28, turns off the commutation tator 25 and switches on switch 24. The next horizontal sync pulse returns to its original position counters 18 and 19, switches switches 23 and 26, connects the code outputs of the counter I8 to the address inputs of the storage device 21, the code codes of the counter 19 to the address inputs of the memory 22, outputs reading the storage device 21 through the switch 27 with the address inputs of the storage device 28, turns on the combo, mutator 25 and turns off the switch 24, etc. When a video pulse starts, one of the tracks from camera 6, for example, on the second scan line, switches counter 19, which provides a sample of the following memory register 22, is fed to delay circuit 15, driver 16 and measuring unit 8, where in blocks 9 and 10 The coordinates of the beginning of the track are measured, in block 1 1 the amplitude of the video impulse and in block 12 the area of the element of the track between the scan lines. At the end of the video pulse from the camera 6 on the code of the driver 16, a signal is generated that is fed to the counting input of the track counter 20 and the control inputs of the switches 24, 25, 27, 29 and the summing unit 14. The counter 20 switches,: and its code outputs through the switch 25 connected to the recording inputs of the device 22, ensuring the recording of the code number of this track. The switch 27 turns off the outputs of the switch 26 for the duration of the control signal, and connects the code outputs of the counter 20 to the address inputs of the storage device 28, which ensures the selection of the memory register of the track. The reception register of the summing unit 14 for the duration of the signal is disconnected from the outputs of the third segment of the storage device 28 and is set to the initial position. The signal from the second output of the driver 16, which starts later and ends earlier than the first signal, is fed to the switch 29-. The data of measuring the coordinates from blocks 9 and 10 and the amplitudes of the video signal of block 1 I are recorded in the first segment of the storage device 28, and the output code of the summing block 14, equal in this case to the code from the area meter 12 in the third segment of the device 28. Repeated video pulse the track in question on the next scan line switches the counter 19, providing a sample of the next memory register of the device 21, enters the delay circuit 15, the driver 16 and the measuring unit 8, where its parameters are measured in the manner described. parameters of. The output signal of the delay circuit 15 for the horizontal scanning period (the video impulse of the day track to the pre-sweep line) goes to the driver 16, which generates a switch 18 signal delayed relative to the recording signal to the sign memory 28 from block 32. Counter output code 18 enters through the switch 23 to the address inputs of the storage device 22, providing a sample of the storage register in which the code of the track number recorded on the previous scanning line is stored. This code through switches 26 and 27 is fed to the address inputs of device 28, which provides a sample of the storage register of the track. The output code of the third segment is fed to the receiving register of the summing block 14. The video pulses of the track on the current and previous lines, which are fed to the inputs of the imaging unit 16 from the camera 6 and the delay circuit 15, fully or partially coincide. Therefore, at the end of the video pulse from camera 6, the fourth output of the driver I6 produces a signal whose temporal position coincides It is a time position signal on the first output of the shaper. This signal is fed to the control inputs of the switch, tori 24, 25, and 29 and sum 28 of the world unit 14 and connects the readout outputs of the device 22 to the recording inputs of the device 21 through the switch 24, ensuring that the code of the track number is overwritten, and turns off the signal receiving register of the summing unit 14 from the read outputs of the third segment of the storage device 28. The signal from the second output of the driver 16 enters the switch 29 and records the output code of the area sum of the scanned sections tr ka from the output of summing block 14 to the third segment and the measured parameters of the video pulse from blocks 9, 10 and 11 to the second segment of the storage register of this track of the device 28. The process of measuring and recording the parameters of the video pulses of tracks on subsequent sweep lines is similar to the previous one. Recording parameters of repeated video pulses of the track performed in the second segment of the storage device 28. At the end of the track scan, in the first segment of the storage register of this track, the coordinates Hz, YH and the amplitude of video Nala Itz beginning of the track, the second track parameters of the cone segment - Xn, YK UK and in the third - the track area. On the next line, after the end of the track sweep, a signal appears at the output of the delay circuit 15, which is fed to the shaper 16. The latter produces a switch signal of the counter 18, which ensures the correct reading order of the remaining tracks. The measurement and recording of the parameters of the remaining tracks is done similarly. Proper selection of the storage registers of device 28 is ensured by sequentially registering track numbers in devices 21 and 22 in order of the arrival of video pulses on scan lines. When a track crosses the raster boundaries or intersections of tracks, their linear dimensions and amplitude parameters of video signals are distorted. Therefore, such tracks are excluded from the total array of measurement data. In these cases, the test bit of the memory registers of the device 28 is recorded

a sign, for example, a logical unit.

To determine the intersection of the image boundaries by the track, the shaper 33 (Fig. 3), to the input of which line pulses from the camera 6 are fed, generates a pulse sequence forming the boundary of the working area of the raster 48 (Fig. 4). This sequence and the video signal from the camera 6 are supplied to a coincidence circuit 42, the output of which, at the end of the video pulse of the track, coincides with the input signals and produces a pulse. This pulse is applied through the OR circuit 47 to the check bit of the selected storage register of the given track of the device 28 for recording the crossing sign.

To determine the mutual intersections of the tracks, the video pulses of the tracks from the camera 6 are fed to shapers 34 and 35, producing short signals, coinciding respectively with the beginning and end of the original signals, and the video pulses from the delay circuit 15 to shapers 36 and 37, the output signals of which coincide respectively with the beginning and the end of initial pulses.,

when the video pulse from the camera 6 and the signal from the driver 37 at the output of the coincidence circuit 38 coincides, a signal is generated which switches the RS flip-flop 43, which is returned to its initial state by a signal from the driver 35. The trigger 43 supplies the resolving potential to the coincidence circuit 39, to the second the input of which is fed from the imager 36. When the video pulse of the delay circuit 15 coincides with the signal from the imager 36 at the output, the signal that triggers the trigger 45 appears during the coincidence circuit 40. The trigger 45 returns to the output The position of the signal from the imager 37, delivers the resolving potential to the 41 coincidence circuit.

When the tracks of type 49 intersect (Fig. 4), the output of the circuit 39 produces a signal that switches the RS-flip-flop 4 and is fed through the OR 47 circuit to the input of the control bit of the selected storage register of the first intersecting track of the device 28. shaper 1b produces a signal that switches over counter 18, which provides a sample of the second intersecting track from the device 28 of the e-memory register. The output signal of the trigger 44, which is returned to the initial state by a signal from the imaging unit 37, is fed to the imaging unit 46. The signal from the output of the imaging unit 46 is fed through the circuit OR 47 to the input of the test bit of the storage register of the second intersecting track of the device 28,

FIG. 5a shows a time diagram of the output X signals of the delay circuit 15 (53), camera 6 (54), coincidence circuit 38 (55), trigger 43 (56), coincidence circuit 39 (57), trigger 44 (58) and driver 46 (59 ) for four possible cases of the relative position of the video pulses on the current and previous scan lines at the intersections of tracks of type 49.

When intersecting tracks 50 (FIG. 4) for a video impulse, cross the tracks from camera 6 partially overlap with one video impulse from delay circuit 15. Therefore, in accordance with the VII procedure with the signal processing procedure in the track separation unit 17, the recording of the parameters of such tracks takes 5 seconds to the same storage register of the device 28. In this case, the output of the 4 matching circuit, the second input of which is connected to the output of the imaging unit 34, is formed cash This signal, via the OR circuit 47, is fed to the input of the test bit record of the memory register of intersecting tracks of the device 28.

Nachfig. 5f shows the time5 on the output signal diagram of the delay circuit 15 (BD), camera b (b) of match 40 (62), trigger 45 (63) and match 41 (64) for various options of mutual arrangement of video pulses of intersecting tracks of type 50 on the current and previous sweep lines. The remaining intersection variants, for example 5 and 52 (Fig. 4), are 5 combinations of the cases described. In this case, the circuit 32 operates in a similar manner.

Claims (2)

At the end of the image sweep, the contents of all the registers of the reminder device 28 are read into the functional block 30, where for all the tracks, except for the intersections marked by the intersection, the speed components are calculated with formulas (9, 10 and II) and ( 12) the coordinates of the point, to which the found values should be attributed. At the boundaries of the liquid volume 3 under study, the illumination of particles and the amplitude of the video signal sharply decrease, which leads to an increase in the calculated values of the Z coordinates, or 2c and the length of the track projections. Therefore, the tracks crossing the boundaries of volume 3 are eliminated. where are the values., d (. are determined based on the measurement conditions. Functional block 30 may be made on the basis of a microprocessor or consist of a number of known summation, multiplication and division blocks, and calculating the logarithm It can be performed by presenting the function Cf, in the form of a Taylor series, whose number of members is limited by measurement error. From the output of block 30, measurement data is fed to register unit 31 for output to a table, a printing device, writing to intermediate media or transmissions in a computer. Formula of the invention. A device for measuring the spatial distribution of the liquid flow rates, comprising a light source with a right-angle diaphragm, whose optical axis is orthogonal to the flow direction, progressive scan television image, the optical axis of which is orthogonal to the optical axis of the light source and the direction of fluid flow, the pulsed exposure unit, the delay for the horizontal scan period, the measuring unit, made in the form of two digital longitudinal and transverse coordinates and the scaling unit, sequentially connected storage device, functional unit and registration unit, while the output of the sync generator of the camera is connected to 812 block input The first output is connected to a pulse exposure unit, the second output is connected to a longitudinal coordinate meter, and the third is connected to a transverse coordinate meter, characterized in that, in order to expand the functionality of the device by measuring the volume distribution of the three components of the flow velocity vector , the pulse former, three pulse counters, two storage devices, six switches and the cross track intersection analyzer, and the meter A digital block is a digital video signal amplitude meter, a digital track area meter between scan lines and a summing block, while the television camera’s signal output is connected to the counting input of the first counter, the inputs of the delay circuit, the pulse former, the cross-section analyzer and the signal inputs of the coordinate meters, amplitudes and plo (adi, the output of the delay circuit is connected to the second input of the pulse former and the intersection analyzer, the output of the camera's synchronous generator is connected to the installation inputs of the first and second counters and the control inputs of the first, second, third and fourth switches, the first output of the pulse former is connected to the counting input of the second counter, the second output is connected to the control input of the summing unit, the counting input of the third counter, the second and third switches and the control inputs of the fifth and third switches, the third output with the third control inputs of the second and third switches and the second control inputs the inputs of the sixth switch and the summing unit, and the fourth output with the third control of the input of the sixth switch, the fourth output of the scaling is connected to the second input of the amplitude meter, and its fifth output to the second input of the area meter, the code output of the first counter is connected to the first code1 input the first switch, the code output of the second counter with the second code input 12 of the first switch, and the code output of the third counter with the first code inputs of the second, third and fifth switches, the address input of the first go: the memory device is connected to the code output of the nth switch, the address, the input of the second additional memory with the first code output of the first switch and the address input of the third additional memory to the second code output of the first switch, the recording input of the first memory device is connected to the code output the sixth switch and the output of the cross track intersection analyzer, the recording input of the second storage device to the code output of the second switch, and I Records of the third storage device are connected to the code output of the third switch, the output of the second storage device is connected with the second code input of the third switch and the first code input of the fourth switch, and the read output of the third storage device with the second code input of the second switch and the second the code input of the fourth switch, the code outputs of the coordinate meters and the amplitudes of the video signal are connected to the first code input of the sixth switch, and the code output of the square meter and - the first input of the summing block, a second code input connected to the output of the last audio by reading the first memory, and its output - to the second input of the sixth Kodo vomu switch koovyi output of the fourth switch coupled to a second input of said fifth code switch. 2. The device according to claim 1, wherein the track cross-section analyzer has five pulse drivers, four coincidence circuits, three triggers and an OR logic, with the first input of the analyzer connected to the inputs of the first and second drivers and the first input of the first circuit , matches, the author's input is with the inputs of the third and fourth drivers and the first input of the second coincidence circuit, the output of the third driver is connected to the second input of the first coincidence circuit and the first input of the first and second triggers, the first The third input of the third trigger is associated with the output of the first coincidence circuit, the second input is connected with the output of the first driver and the second input of the second coincidence circuit, and the output with the first input of the third coincidence circuit, the second input of the latter is connected with the output of the fourth driver, and the output with the first the input of the OR circuit and the second input of the first trigger, the output of the first trigger through the fifth driver is connected to the second input of the OR circuit, the second input of the second trigger is connected to the output of the second coincidence circuit, and its output is to the first input of the fourth Cx We coincidences, the second input of the latter is coupled to the second vthodom shaper, and the output - to the third input of OR gate, the output of OR gate connected to the output of the analyzer mutual intersections of tracks. FIG. one .2i / 51 H 2 J four/ eight / X 50 R Ri z /: 9 Fy 555 57