Two-Dimensional Aerodynamic Characteristics of Several Polygon-Shaped Cross-Sectional Models Applicable to Helicopter Fuselages
NATIONAL AERONAUTICS AND SPACE ADMIN LANGLEY RESEARCH CENTER HAMPTON VA
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A wind-tunnel investigation was conducted to determine two-dimensional aerodynamic characteristics of nine polygon-shaped models applicable to helicopter fuselages. The models varied from 12 to 15 scale and were nominally triangular, diamond, and rectangular in shape. Side force and normal force were obtained at increments of angle of flow incidence from -45 deg to 90 deg. The data were compared with results from a baseline UH-60 tail-boom cross- sectional model. The results indicate that the overall shapes of the plots of normal force and side force were similar to the characteristic shape of the baseline data however, there were important differences in magnitude. At a flow incidence of 0 deg, larger values of normal force for the polygon models indicate an increase in fuselage down load of 1 to 2.5 percent of main-rotor thrust compared with the baseline value. Also, potential was indicated among some of the configurations to produce high fuselage side forces and yawing moments compared with the baseline model.