Author(s): Ravi Kumar Assudani; Richard Huber; Peter Rutschmann; Anupam Dewan
Keywords: Modeling; Cavitation; Large eddy simulation (LES); Tip vortex; Shear vortex layer
Abstract: A three-dimensional, unsteady, incompressible flow in a horizontal channel with a prismatic obstacle placed at its geometric center has been investigated numerically using a commercial code, FLOW3D version 9.2. Various cavitation regions at different sections along the channel have been identified by observing the pressure contours. Three different turbulence models, namely, the one equation turbulent energy model, the standard k-ε model and the renormalization group (RNG) k-ε model have been used to close the system of governing equations. Large eddy simulation (LES) has also been performed. Of these, LES is found to capture the flow physics and bubble formation phenomenon most accurately, while illustrating both tip vortices and shear vortex layer. The bubble producing regions obtained have been compared with the experimental data and cavitation occurrence has been verified by comparing the pressure value with the expected cavitation pressure value obtained from definition at the system conditions. Along with the pressure contours, velocity contours have also been portrayed to depict the flow behaviour.