Effect of mesh resolution on large eddy simulation of cloud cavitating flow around a three dimensional twisted hydrofoil

Unsteady cavitating turbulent flow around a twisted wing is simulated by using the large eddy simulation method. Two sets of grids with 10 million and 2 million nodes are used to investigate the influence of mesh resolution on the results. The results of non-cavitating flow with the coarse mesh agree well with the experiment, but the accuracy of the fine mesh results is remarkably higher for the cavitating flow, which indicates that more nodes are needed for the cavitating flow simulation than the non-cavitating flow. Then the parameters affecting the grid resolution are investigated. It is observed that the small size shedding vortex can only be captured by the fine mesh and the smaller grid spacing in the spanwise direction is needed to capture the details of re-entry jet. The re-entry jet in spanwise direction can affect the overall development of cavities, which is sensitive to the pressure gradient and spanwise resolution of the mesh. (C) 2015 Elsevier Masson SAS. All rights reserved.