Implicit Large Eddy Simulation of Tip Vortex on an Elliptical Foil
Paper i proceeding, 2017
In this study, Implicit Large Eddy Simulation (ILES) in OpenFOAM has been employed to study tip vortex flow on an elliptical foil. This type of foils has similar tip vortex behaviour as a propeller, making it a suitable benchmark for both numerical and experimental investigations of tip vortex flows in cavitating and non-cavitating conditions. The study includes investigation of the impact of streamwise and inplane mesh resolutions in tip vortex roll- up and its transportation. Vortex properties such as trajectory, axial and inplane velocity distributions, and also vortex core pressure distributions are computed for each mesh resolution and compared with available experimental data. Comparisons show that at least 16 cells per vortex diameter in inplane section is required to predict the tip vortex in the near field region. Results of varying foil angle of attack show the capability of the current numerical approach in ranking tip vortex properties. Employed numerical approach is fully capable of capturing the accelerated axial velocity at the vortex core for different operating conditions, and shows very good agreement with the experimental observations.