Special Opportunities in Helicopter Aerodynamics

Aerodynamic research relating to modern helicopters includes the study of three-dimensional, unsteady, nonlinear flow fields. A selective review is made of some of the phenomena that hamper the development of satisfactory engineering prediction techniques, but which provide a rich source of research opportunities: flow separation, compressibility effects, complex vortical wakes, and aerodynamic interference between components. Several examples of work in progress are given, including dynamic stall alleviation, the development of computational methods for transonic flow, rotor-wake predictions, and blade-vortex interactions.

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