Oil flow studies of base separation at supersonic speeds

Oil flow visualization tests were conducted on the base of a 10-degree half-angle cone model at Mach numbers 1.75 to 4.0. The cone was supported by a strut from the cone surface to the wind tunnel floor. Previous tests on a sting supported cone showed separation to occur on the cone base at distances on the order of 15% of the base radius from the trailing edge corner. Results of this test program show that separation occurs at slightly greater distances from the corner than for the sting supported model; also, the separation line was irregular indicating large asymmetries in the base flow even though the model was at zero degrees attitude.