Mass transfer rate effects on the cavitating vortex shedding flow around a circular cylinder at low Reynolds number

Abstract

Cavitating vortex shedding is a flow phenomenon commonly encountered behind bluff bodies in hydraulic machinery and systems and the generated vapor bubbles significantly change the dynamic behavior of the vortices. In addition, the collapses of the cavities become a source of unwanted effects such as vibration, noise and material erosion. In this study, the numerical results of the cavitating vortex shedding behind a circular cylinder at low Reynolds number have been compared and analyzed using different mass transfer rate values between the vapor and the liquid water phases. For that, the transport equation for the vapor volume fraction coupled with the explicit source term based on the simplification of the Rayleigh-Plesset equation has been solved. Commonly, this explicit source term that accounts for the mass transfer rate is driven by a function of the pressure difference, the vapor volume fraction and several empirical factors. To understand the effects of this rate, its value has been gradually increased from its default value up to the infinite when the equilibrium assumption for the barotropic flow is satisfied. The obtained results show that as the rate is increased, higher gradients of the vapor volume fraction and of the pressure near the interface between the vapor and the liquid phases are predicted. However, the frequency of the vortex shedding is slightly affected by the increase of the mass transfer rate.

Peer Reviewed

Postprint (author's final draft)