Effect of cavitating flow on forced convective heat transfer: a modeling study

With water as working medium, a numerical study on liquid convection heat transfer accompanied by cavitating flow in a circular tube was conducted by combining mixture model and Schnerr-Sauer cavitation mode in the commercial code, Ansys Fluent. Cavitation is instigated by setting a restriction orifice in the circular tube. The simulation results show that cavitation occurs around the wall of the restriction orifice and disappears at the downstream regions. The comparison of local heat transfer coefficients under the same mass flow rate indicates that, heat transfer is significantly augmented at the downstream regions of the restriction orifice because of the occurrence of cavitation. The analysis on the characteristics of cavitating and noncavitating flows confirms that the occurrence of cavitation can increase the turbulence intensity under the same mass flow rate, which is the origin for heat transfer to be enhanced. Based on it, the effects of such factors as inlet pressure and ratio of orifice to pipe diameter on cavitation enhanced heat transfer were further investigated for the purpose of application.