Abstract:
The impact on the aerodynamics of a fixed wing, UAV and rotary wing, due to the presence of a ground and free surface in close proximity, is studied using computational methods in this work. The Reynolds Averaged Navier Stokes (RANS) equation are solved for the fluid flow, while the interface between the two fluids is captured using the Volume of Fluid (VOF) technique. The motivation behind this work is to study the effect of wavy or calm surface of a water body or sea on the fixed wing and rotor aerodynamics and compare the difference in the vicinity of a rigid ground surface, which is the approach normally taken to model ground effect in most of the existing computational studies. In order to study the perturbation of the free surface, this study uses a multiphase approach to capture the free surface, rather than pre defining it as a rigid boundary. Waves of different patterns are generated by using appropriate source terms in the momentum equation (by way of a numerical wave maker) and the effect of these on the fixed wing and rotor aerodynamic characteristics are analyzed. The results observe a significant variation in aerodynamic quantities depending on the wave characteristics.