The effects of metallized fuel composition on the combustion characteristics of solid fuel ramjets.

Abstract

A series of experiments were conducted to investigate the effects of metallized fuel composition on the combustion characteristics of solid fuel ramjets (SFRJ). Metallized fuels were burned in a two dimensional SFRJ motor under conditions similar to the actual flight conditions proposed for solid fuel ramjets. Pressure, air inlet temperature and flowrate measurements were taken using an automatic data acquisition system. High speed motion pictures were taken of the interior of the combustor during the burning of the solid fuel through two viewing windows located in the recirculation zone and just prior to the aft mixing chamber where the boundary layer was more fully developed. Tests were conducted at mass fluxes of 0.2 and 0.5 lbm/in2 sec, with pressures ranging from 57 to 200 psia and with a nominal inlet air temperature of 1100° R. The surface of most fuels had a characteristic shedding of small, unignited flakes. The flakes are thought to be binder material, and were more prevelent at lower pressures. Occasional shedding of large surface layers was observed, especially during motor shutdown. Metallic surface agglomerations appeared to interact strongly with these irregular surface layers. Large magnesium particles exhibited the expected bright ignition characteristics. Boron particles were not observed, apparently because they were smaller than the resolution limits of the motion pictures.