Investigation of the cavitation processes behind a cylinder located in a microchannel in a wide range of Reynolds numbers

Numerical modeling and experimental investigation of hydrodynamic cavitation on a micro -cylinder located in a microchannel were carried out. The Zwart-Gerber-Belamri cavitation model was employed to simulate cavitation processes, and turbulence was simulated using the LES model. Experimental studies were performed by visualization with a shooting frequency of 960 Hz. Fluid pressure at the channel inlet ranged from 2 to 30 bar. Time dependences of pressure, velocity and vapor volume fraction, as well as their average values, were obtained at five points. Stable developed cavitation was found to exist for inlet pressures above 18 bar; no cavitation at all was observed for inlet pressures below 8 bar as confirmed by experimental studies. A fairly good agreement was revealed between the calculated and experimental data. The cavitation pulsation frequency (480-2200 Hz) and hydrodynamic pulsation frequency values (26-96 kHz) were ob-tained. The presence of cavitation was shown to shift the frequency of hydrodynamic pulsations towards larger values. Dependence of the relative drag coefficient on the inlet pressure, well approximated by a correlation zeta r = (2 & UDelta;p)0.5, was obtained.

Automated summary

Numerical modeling and experimental investigation of hydrodynamic cavitation on a micro-cylinder located in a microchannel were conducted, showing stable developed cavitation within a certain range of inlet pressures. The presence of cavitation was found to shift the frequency of hydrodynamic pulsations towards larger values.