Pressures on a Slender, Axisymmetric Body at High Angle of Attack in a Very Low Turbulence Level Air Stream.

This report describes experimental work which has been carried out to investigate the flow over axisymmetric slender bodies at high angles of incidence. Surface pressure measurements were made on the cylindrical section of a rigidly mounted nosecylinder model in a low speed, very low turbulence level freestream at incidences from 30 deg to 90 deg and for the full roll angle range. Tests were performed for a variety of different nose shapes at subcritical Reynolds numbers and the pressure data was integrated to produce local side and normal force coefficient distributions. Much of the data was generated using three calibre ogive nose profiles, but in all cases the model roll orientation was found to significantly affect the side and normal forces. The side forces were reduced by both hemispherical nose blunting and by using shorter ogival noses. A two calibre conical nose was also used. Details of surface oil flow visualisation are presented. Author