Experimental investigation of erosive burning of composite propellants under supersonic crossflows

Combustion products from a solid-propellant gas-generator are made to crossflow at transonic- and supersonic-velocities over the burning surface of a two-dimensional propellant-slab with a ramp at the slab-end - a nozzleless mode of operation. By using a high-speed camera, the burning edge of the propellant slab is observed under these crossflow conditions through a window assembly of polymethyl methacrylate. Presented are the erosive burning rates thus obtained for two composite propellants of the same composition but of different zero-crossflow burning rates (5- and 9-mm/s at 5 MPa). The erosive burning characteristics at transonic and supersonic crossflow conditions are mostly similar to those at subsonic crossflow situations.