Some recent advances in computational aerodynamics for helicopter applications

Abstract : The growing application of computational aerodynamics to nonlinear helicopter problems is outlined, with particular emphasis on several recent quasi-two dimensional examples that used the thin-layer Navier-Stokes equations and an eddy-viscosity model to approximate turbulence. Rotor blades section characteristics can now be calculated accurately over a wide range of transonic flow conditions. However, a finite-difference simulation of transonic flow conditions. However, a finite-difference simulation of complete flow conditions. However, a finite-difference simulation of the complete flow field about a helicopter in forward flight is not currently feasible, despite the impressive progress that it being made in both two and three dimensions. The principal limitations are today's computer speeds and memories, algorithms and solution methods, grid generation, vortex modeling, structural and aerodynamic coupling, and a shortage of engineers who are skilled in both computational fluid dynamics and helicopter aerodynamics and dynamics. Keywords: Vortex interaction; Helicopter aerodynamics; Unsteady transonic flow.