| 摘要 |
FIELD: ecology.SUBSTANCE: method is based on registration of acoustic emission signals from the sources of gas bubbles near the bottom with use of vertical receiving antennas with the fan-shaped directional pattern in the vertical plane, which are preliminary calibrated with use of noise source with the uniform spectrum in the range of operating frequencies, and for determining the distribution function of the bubbles on the sizes D(R) and total gas flow the acoustic emission spectra normalised based on the acoustic calibration are used. Areas of exit of gas from the sources of acoustic noise are determined from the maxima of the correlation function between the signals received from different directions of the vertical directive pattern of receiving antennas and a time shift between them, according to the formula d=S×?, where dis the distances from centres of the first and second antennas to the source, Sis the speed of sound in water, ?is the time shifts for the case of the maxima of correlation functions of each antenna.EFFECT: method takes into account the interaction of pulsing and emitting acoustic signals bubbles with the bottom or the working parts of the technical systems, which leads to the change in the own oscillating frequency of bubbles forming in the emission spectrum of the gas exit area and the structure of the pressure field in the far zone which in this case has a dipole character.2 dwg |
