Numerical Analysis of the Unsteady Cavitating Flows in a 2D-Cascade and a 3D-Inducer

The unsteady cavitating flow in a turbopump inducer has been analyzed using CFD simulation results. An accurate three-dimensional detached eddy simulation (DES) code which took into account the cavitating phenomena was used. The three-dimensional code is based on the numerical method for compressible flow using low Mach number flow approximation. The cavitation is modeled by the source/sink of vapor phase in the liquid flow. The code has been applied for cavitating flows in both a 2D cascade and a 3D inducer. The computational results showed similar unsteady behaviors to experimental measurements in terms of the direction in cavity propagations and tendency in cavity developments. Mechanism for the unsteady cavitating flow such as rotating cavitation is investigated by analyzing the numerical results. One model is proposed to describe the reason why the cavity appears to propagate in the forward direction.