ABSTRAKT

In a number of cases a two-phase foam mixture flow in a rectangular channel is accompanied by appearance of geometric resonances. Measurement of resonance frequency at the known parameters of the channel allows one to determine a velocity of sound in a two-phase flow and a characteristic size of "bubbles". Measurements of eigennoises of a vapor-water flow at a mixture temperature of 50°C, a velocity of 50 m/sec, and a volumetric vapor content of 0.727 revealed the range of bubble sizes by a continuous portion of the spectrum and frequencies of resonances (transverse and longitudinal) in the diffuser throat with a cross-section of 6×40 mm and a length of 18 mm.
The results of measurements were compared to the values of a sound velocity calculated by theoretical relations derived by I. S. Radovskii (Moscow Institute of Engineering Physics). Resonances on eight frequencies (transverse and two longitudinal) found in the experiments arise at a sound velocity of 90−400 m/sec and coincide with the calculated values within the error of the experiment (deviation not higher than 4%). The scheme of measurements may be used to diagnose a structure of a two-phase flow at mean values of volumetric vapor content.