Comparison of Turbulence Models for Simulating Flow in Waterjets

We have developed a fast numerical algorithm for simulating flows in complex moving domains. The new hybrid smoothed profile/spectral element method exhibits high-order accuracy as well as great computational efficiency as it removes the tyranny of mesh generation. Here we extend this work by incorporating a variational multiscale large eddy formulation for modeling the subgrid turbulent scales. We present verification and validation studies of the combined method and compare different turbulence modeling methodologies. Subsequently, we apply it to study laminar, transitional and turbulent flows in an axial-flow waterjet propulsion system (ONR AxWJ-1). The robustness and efficiency of our methods enable parametric studies of many cases, which may aid greatly in the early stages of design and evaluation of such propulsion systems.