SU1434361A1 - Method of measuring propagation velocity of acoustic oscillations in moving media - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure the velocity of propagation of acoustic oscillations in streams of moving media. The aim of the invention is to increase the accuracy of control by reducing the period of loss of information about fluctuating flows. According to the method of measuring the velocity of propagation of acoustic oscillations in the flows of moving media in the medium under study, a series of pulses of acoustic oscillations are excited, these pulses are received, the propagation times of these pulses are measured on a predetermined base, pulsations of the flow rate of the medium are measured by measured times, and the pressure differential in The emission and reception zones and the ratio of the pulsation of the flow rate to the pressure drop determine the speed of propagation of acoustic oscillations. 1 silt. S (l

Description

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with

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The invention relates to a measurement technique and can be used to measure the speed of propagation of acoustic oscillations in streams of moving media.

The aim of the invention is to improve the accuracy of control over the calculation of the period of detailed information about

fluctuating flows.

; The drawing shows devices for measuring the speed of propagation of acoustic oscillations I The device contains transmitting and receiving electroacoustic transducers 1 and 2 connected through a switch 3 to a transceiver unit | chik 4 and two amplifier 5 and 6 preformer the time inter- shaft is a digital value, a power supply unit 8, an integrator 9, an analogue digit figure converter 10, a synchronizer 11 and a digital computing DEVICE 12.

I The method of measuring the velocity of propagation of acoustic oscillations in | moving media is carried out as follows.

At a predetermined period of time, the transmitter of the transceiver 4 is triggered by pulses post-sync with synchronizer 1 with a period of 5 q ". Simultaneously probing the flow, acoustic pulses are radiated from the IB direction of the flow by an electroacoustic converter 1, the electroacoustic converter 2c is received. the pulses arrive at the electroacoustic converter 1 from the transmitter output of the transceiver 4 through switch 3 and the acoustic pulses received by the electroacoustic converter 2 switch 3 provided to the receiver input of the transceiver 4 ,, transceiver operation control 4 and the switch 3 is performed automatically synchronizer 11, was measured delay time of Eignalov, wherein the passage of acoustic 1esko- th pulse is determined of expressing a

c (t) -v (t) cos5

where c (t) is the time dependence of the ultrasound velocity in the flow- Ket

v (t) is the time dependence of the flow velocity;

d is the base distance between the electroacoustic transducers; v is the angle between the vector of the flow velocity and the direction of radiation of the probe signal.

The probing is carried out periodically, with the period C between the probe pulses being established from the condition

bcpcf u;

where with

 effective duration of the probe pulse;

probe signal transit time. in controlled flow during i-ro cycle

The received pulses from the output of the transceiver 4 are fed to the input of the converter 7 of the type time interval — a digital value, where the value is 3; converts into a proportional digital value C - N, and then, in a reciprocal digital value of 1 / N; and enters the input register of the first input of the digital computing device 12, the operation of the converter 7 type time interval - digital value (Implemented by the synchronizer 11. The digital difference value of the times 1 / Nj and 1 / N (.i delays of acoustic signals after each i- ro and (i + 1) - th cycles is determined by the hyphenation

J

N;

±

%.about

& v (t) coso6

Subtract 1 / N | and l / Nj,., -, is carried out in a digital computing device 12 "Simultaneously with the measurement of the velocity ripple uv (t} of the flow in the time interval &; between the emitted and received pulses, the switch 3 switches the electroacoustic transducers 1 and 2 To the inputs of voltage amplifiers 5 and 6, In each measurement cycle, voltage inputs varying with time at the inputs of amplifiers 5 and 6 are proportional to the current hydrostatic pressure in the emission zone of the acoustic impulse P, (t)

VNIIPI Order 5550/47

Random polygons pr-tie, Uzhgorod, st. Project, 4

Circulation 847 Subscription

Claims (1)

Claim A method of measuring the propagation velocity of acoustic vibrations in moving media, which consists in the fact that pulses of acoustic vibrations are emitted into the controlled medium, the pulses of the past vibrations are received, and the propagation time of each pulse is measured, taking into account which the propagation velocity is determined, characterized in that, in order to increase accuracy measurements when measuring in moving at a variable speed medium, additionally measure the pressure drop in the areas of radiation and reception of acoustic vibrations, determine pulsations of the flow velocity of the medium according to the measured transit times, and the propagation velocity of acoustic vibrations is judged by the ratio of the velocity pulsation to the pressure drop. VNIIIPI Order 5550/47 ____________ Circulation 847 Subscription Custom polygr. ave, city of Uzhhorod, st. Project, 4