Helicopter Hovering Performance Studies. I. Vortex Wake Analysis. II. Test Facility. III. Blade Tip Pressure Distributions.

摘要

Results are presented from studies of several problem areas which are related to helicopter hovering performance prediction. A working hypothesis is described for including the tip vortex core effect in a vortex wake analysis and it is shown that the tip vortex geometry in the near wake can be calculated with good accuracy for rotors having fewer than five blades. A hovering model rotor test facility of reduced size is described. Data from this facility include measured pressure distributions on the tip of a single-bladed rotor. (Author)