Structure of the burning surface of powder under conditions of blowing

The surface structure (roughness) of ballistite powder burning under conditions of blowing past the surface is studied. The parameters varied in experiments are the caloricity of powders, the burning rate, the pressure, and the blowing velocity. Regular macroscopic roughness is found on all the specimens examined. A dependence of the roughness height on the blowing velocity and pressure is established. A formula for evaluation of the reduced height of the roughness is derived. Based on the analysis of experimental data, a hypothesis on the roughness-formation mechanism under conditions of blowing is proposed.