Modeling and analysis of a cavitating vortex in 2D unsteady viscous flow

Two models, of which one analytical and the other computational, have been developed to describe an axisymmetric cavitating vortex in two-dimensional, unsteady, incompressible and viscous flow. The models are used to investigate the influence of viscosity on the flow structure, cavity size and cavity resonance frequency. The analytical formulation is an extension of the Lamb-Oseen vortex and has not been presented before. It is derived under the assumption of small radial velocity equivalent to small temporal changes of the cavity diameter. The computational model solves the equations without simplifications. It is shown that viscous effects have a significant influence on cavity radius and resonance frequency if the cavity size is on the same order or smaller than the viscous core size.