The free-wake prediction of rotor hover performance using a vortex embedding methodA method is developed to predict the rotor hover performance. This method solves the compressible mass conservation equation much like current full potential codes and can therefore predict the transonic flows on a rotor. However, the newly developed approach also allows for the free convection of shed vorticity and permits the computation of the entire hover wake system. The method uses a vortex embedding scheme in potential flow and has been implemented in a computer code, HELIX -I. To predict power we implement a simple boundary layer and two different induced-drag integration schemes. The induced-drag is obtained from surface pressure integration and an energy flux integral. Comparisons between computations and experiment show good agreement for the prediction of power polars, surface pressure distribution, and tip vortex geometry.
Document ID
19890041072
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Ramachandran, K. (Flow Analysis, Inc. Mountain View, CA, United States)
Tung, C. (NASA Ames Research Center Moffett Field, CA, United States)
Caradonna, F. X. (NASA Ames Research Center; U.S. Army, Aeroflightdynamics Directorate, Moffett Field CA, United States)