A computational method for cavitational flows based on energy conservation

Abstract

In flow with cavitations, incompressible liquid and compressible vapour coexist. Phase transition in the flow results in complex thermophysical processes. The flow field is discontinuous with density varying greatly near the bubble wall. Existing computational fluid dynamics (CFD) methods cannot simulate this complex physical phenomenon accurately. In the current paper, based on primitive variables, namely pressure, velocity, and enthalpy, a new preconditioning method specifically dealing with the unsteady flow field with cavitation is established. The fundamental equations, which adopt the energy equation instead of the conventional cavitation model, are discretized using Roe's scheme to capture the discontinuous surface. A divisional computational method of state parameters for H₂O, based on pressure and enthalpy, is constructed. It can be applied to liquid region, saturation region and vapour region. The examples indicate that this method can be used to capture the unsteady cavity in the flow field.