Geometric effects on the combustion in solid fuel ramjets

The paper summarizes an experimental investigation concerning the geometric and size effects on the cumbustion in solid fuel ramjets (SFRJs). Polymethylmethacrylate (PMMA) solid fuel was used, and the combustor simulated conditions resulting from flight at sea level and Mach 3, Instantaneous and local fuel regression measurements indicated the following conclusions: the local regression rate is closely related to the local convective heat flux; the honuniformity of fuel regression rate has an attenuating effect on the dependence of the mean regression rate on the mass flux in extended burn-time tests; the regression pattern is not affected by downstream conditions; and mean regression rate decreases with increasing port diameter. Nondimensional scales normalized by the port diameter were found to give generalized expressions for different motors.