Pressure Distributions and Wave Drag Due to Two-Dimensional Fabrication-Type Surface Roughness on an Ogive Cylinder at Mach Numbers of 1.61 and 2.01

Abstract : TUBES, Sehlieren photography, Aircraft finishes. Ten types of surface roughness, including step, wave, crease, and swept configurations were investigated. The tests were made on an ogive cylinder of fineness ratio 12.2, the roughness elements covering the cylindrical portion of the model. Wave drag was the major component of the drag due to roughness at supersonic speeds. The pressure distributions over the roughness elements were generally in good agreement with linearized two-dimensional theory except for regions of the elements affected by boundary-layer separation and shock detachment. There was little or no effect of Reynolds number except on the pressures within the regions influenced by separation of shock detachment. The wave drag decreased as the free-stream Reynolds number was decreased. (Author)