抄録
We focus our attention on the low pressure area in turbulent fine vortices, which is Burgers vortex type and closely related to cavitation inception, because it has been ignored in previous methods for cavitating flow simulation. As a basis of model construction, the interaction between a Burgers vortex and cavitation is investigated by the direct numerical simulation (DNS). The vortex is artificially reproduced to represent a fine-scale elementary motion in fully developed turbulence. The results show that both the circumferential velocity and the streamwise vorticity distributions shift due to the sudden expansion by cavitation inception. Assuming the circulation is kept constant, we derive a new model which represents velocity modulation of an elementary vortex for the case of cavitation. Our model successfully explains the DNS results. This simple model can become the basic concept of cavitating turbulence model.
