SU894631A1 - Method of determining acoustic energy flux - Google Patents

Description

(54) METHOD FOR DETERMINING ACOUSTIC POWER FLOW

 I. .

The invention relates to radio engineering and can be used to determine the acoustic power and location of sound sources. There is a known method for determining the flow of acoustic power, based on the measurement of the instantaneous magnitude of the sound-pressure at the point of the sound field 11 under study.

However, the known method has a low accuracy — the known or changing source location of the sound.

The purpose of the invention is to improve the accuracy.

For this in the method of determination. Acoustic flux flow, based on measuring the instantaneous sound pressure at the point of the sound field, measures the instantaneous values of the three orthogonal components of the medium’s oscillatory velocity at the same point, multiplies the sound

pressures on the corresponding values of the components of the oscillatory velocity, integrate the products in time, and determine the values of the active orthogonal components of the acoustic power flux, multiply the phase-shifted phase of the sound pressure by the corresponding values of the vibrational velocity components, integrate the products

10 times and determine the magnitude of the reactive 1x orthogonal components of the acoustic power flux.

The drawing shows a structural diagram of one of the options for realizing the proposed method.

The method is carried out as follows.

At a given point, for example, at a selected point inside the passenger compartment of the car, a three-component receiver 1 of the kinematic parameter of the medium of oscillatory air velocity with a speed converter is installed.

into electrical signals and a sound pressure receiver 2 with conversion of the measured parameter into electrical signals.

During operation of the vehicle, these devices simultaneously measure the instantaneous sound pressure and the instantaneous values (the three orthogonal components of the air velocity.

The received electrical signals are passed through amplifiers 22 and filters 4. Using three multipliers 5, one input of which gives a common sound pressure signal, and the other inputs separate signals of oscillatory CKOpoQ components, multiply the sound pressure values by the corresponding values of the components of the oscillatory velocity. The signals from the outputs of the multipliers 5 are passed through the integrators 6, thereby integrating the products obtained over time. Then register. The resulting signals correspond to the values of active orthogonal components of acoustic power. At the same time, the signals corresponding to the values of the zigzag pressure are passed through the phase shifter 7 by 90, thereby shifting

instantaneous value

sound pressure at 90 in phase relative to the instantaneous values of the oscillating velocity cosyunents. The signal from the output of phase shifters 7 is fed to one input of three, other multipliers &; to the other inputs of which separately send signals of the components of the oscillatory velocity. Using these (multipliers 8, multiply the shifted sound pressure values by the corresponding vibrational velocity values. Signals from the outputs of the multipliers 8 are passed through integrators 9, thereby integrating the obtained products over time and then register the received signals corresponding to the reactive orthogonal components of the acoustic power.

The active components of acoustic power thus determined can be used to determine the magnitude of the acoustic power flux and the direction to the sound source, for which a power flux vector is constructed, the magnitude of which determines the flux value

the acoustic power at a given point of the field, and the direction of the sound source is determined from the direction. From the values of the active and reactive components, the distance to the sound source can be determined if measurements are made in the near field.

The described method allows to increase the measurement accuracy.

To clarify the location of radiation sources associated with the elemental structures, each of these elements located in the direction of the power flow vector installs a vibration sensor 10, the signals from which are fed through an amplifier 1I and filter 12 to the input of an additional multiplier 13, to another input of which give signals from the outputs of multipliers 5 and 8.

The signal from the output of the multiplier 13 is fed to the integrator 14. Then the ratio of the signals at the output of the integrator 14 n at the outputs of the integrators 6 and 9 is determined.

According to the degree of nx correlations, the correspondence between the signal and oscillations of the structure element is determined. Transferring the transmitter 10 from one element to another, or switching vibration sensors mounted on different elements, you can determine the building element that is the source of the sound.

The proposed method allows to increase the measurement accuracy.

Formula invented

The method for determining the flow of acoustic mode, based on the measurement of the instantaneous magnitude of the sound pressure at the test point of the sound field, different

By the fact that, in order to increase accuracy, instantaneous values are measured simultaneously at the same point. Three orthogonal ones. components of the vibrational velocity of the medium, multiply the sound pressure value by the corresponding

wellness) of oscillatory components

speeds, integrated. penetration

over time and determine the values

active orthogonal components

the acoustic power fluxes, multiply the sound pressure level shifted in phase by 90 ° by the corresponding magnitudes of the components oscillator 588963 4

speed, integrate the product-information sources,

in time and determine orders that are taken into account in the examination of reactive orthogonal components I, Patent SP1A 9 1892644 in the flow of acoustic power. cl. 181-05, published. 1932.

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Claims (1)

Claim A® A method for determining the flow of acoustic power, based on measuring the instantaneous value of sound pressure at the studied point of the sound field, different 45 in order to increase the accuracy, instantaneous values are simultaneously measured at the same point. The three orthogonal components of the vibrational velocity of the medium are multiplied by the sound pressure value by the corresponding values of the vibrational components. speeds, integrate the products over time and determine the values of active orthogonal-components 55 flow of acoustic power, multiply the 90 ° phase-shifted sound pressure value by the corresponding values of the components of the vibrational velocity 894631, integrate the products in time and determine the values of the reactive orthogonal components of the acoustic power flow.