Numerical investigation of the transient cavitating flow and vortical patterns around a hydrofoil

The objective of this work is to investigate the cavitating flow mechanism of a specific hydrofoil, Tulin hydrofoil, and better understand the vortex-cavitation interactions in transient cavitating flows. The numerical investigations are performed using a large eddy simulation method and the Zwart cavitation model. The predicted cavity formation and evolution agree well with the experimental observation. An asymmetric vortex street has been formed, with the upper one (the trailing edge vortex street) has a regular vortex shape and a clear boundary between vortex structures, while the lower one (the leading edge vortex street) has a larger cavitation area due to the low pressure distribution on the suction side of the foil. The turbulent kinetic energy transport equation has been adopted to examine the balance and contribution of different mechanisms. The formation and evolution of the leading and trailing edge vortex structures are responsible for the generation and modification of the turbulent kinetic energy distributions. The convection term varies significantly in the cavity region during the phase change process, and the boundary of the vortex structures enhance the production term of the turbulent kinetic energy.