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Two cavitation models are evaluated based on their ability to reproduce the development of cavitation experimentally observed by Winklhofer et al. inside injector hole geometries. The first is Singhal's model, derived from a reduced form of the Rayleigh-Plesset equation, implemented in the commercial CFD package Fluent. The second is the homogeneous relaxation model, a continuum model that uses an empirical timescale to reproduce a range of vaporization mechanisms, implemented in the OpenFOAM framework. Previous work by Neroorkar et al. validated the homogeneous relaxation model for one of the nozzle geometries tested by Winklhofer et al. The present work extends that validation to all the three geometries considered by Winklhofer et al in order to compare the models' ability to capture the effects of nozzle convergence.

The burden of creating meshes increases the cost of Computational Fluid Dynamics (CFD) and slows the rate at which new engine geometries can be investigated. Internal Combustion Engines (ICEs) with moving valves and piston present a special challenge, often requiring numerous different target meshes or case-specific codes for adapting the mesh. The goal of the present paper is to facilitate remeshing by calculating vertex motion, in parallel, for hybrid tetrahedral and hexahedral meshes. The calculated vertex motion is intended to maintain good mesh quality and reduce the need for interpolation to a new mesh. The demonstrated approach uses Laplacian-based smoothing for hexahedral cells and optimization-based smoothing for tetrahedral cells. Further, planar and cylindrical surfaces in the engine geometry are automatically recognized. As the engine volume changes shape, vertices may slide along the planar and cylindrical surfaces.