Cylindrical mesh adaptation for isolated rotors in hover

Abstract

This paper presents inviscid computations of an isolated rotor in hover using a specific mesh adaptation technique. The proposed adaptation method is simple, efficient and dedicated to this type of application. The user provides a short and fine grid around each blade; an overset cylindrical grid that discretizes the remaining part of the computational domain is then automatically generated and periodically adapted to improve the capture of the wake. This technique can also be applied to a portion of a multi-bladed rotor by using periodic boundary conditions. Transfers between blade and cylindrical grid are completed through the Chimera method. Results show that, with about 600 000 points, the tip vortex can be followed for approximately 380 degrees of age. Also, this paper proposes a deep insight into different refinement indicators for this problem.