Revising of the Near Ground Helicopter Hover: The Effect of Ground Boundary Layer Development

The interaction of a helicopter rotor with the ground in hover flight is addressed numerically using hybrid Eulerian–Lagrangian CFD model. When takes off or lands, its wake interferes ground. This interaction, depending on height-to-rotor diameter ratio, causes altering loading and performance as compared to unconstrained case gives rise development complex outwash flow field surrounding helicopter. present study aims characterize interactional phenomena occurring early stages particular interference starting vortex boundary layer effect this motion flow. method employed combines standard URANS compressible finite volume solver, use which restricted confined grids around solid bodies, Lagrangian approximation entire conservation equations are solved their material form, disctretized particle representation quantities. two methods strongly coupled each other through an appropriate iterative scheme. main advantage proposed methodology that it can conveniently handle configurations several bodies move independently from one another, affordable computational cost. In paper, thrust coefficient predictions model free code experimental data indicating consistent prediction load requires inclusion analysis. Moreover, detailed comparisons evolution predicted by presented.