Modeling and Experimental Issues on Thermal Effect of Cavitation

摘要

Cavitation is a phase change phenomenon from liquid to vapor phases.During this process, the latent heat is extracted from surrounding liquid, which decreases the local temperature, and hence the vapor pressure inside the cavity.This is called thermal (thermodynamic) effect of cavitation.This effect is more pronounced for warmer fluid with its temperature closer to critical temperature than colder one, and is known to lead to much better suction performance of pumps and inducers.In the present report, theoretical models including ours are firstly reviewed to recall/understand the underlying physics of thermal effect of cavitation.The achievements of our theoretical works are introduced.Then, other physical effects which may contribute to the quantitative discrepancy between the theoretical analysis and real phenomenon (experimental observation) is discussed.Some numerical assessment and our simple model experiment in a two-dimensional convergent-divergent nozzle flow using a thermo-sensible engineered fluid will be referred to discuss what is necessary for more quantitative understanding of the phenomenon.