Effect of the curvature of the burning surface of condensed energetic materials on the burning rate

Combustion of homogeneous condensed energetic materials (CEMs) with a curved burning surface is considered within the framework of the phenomenological theory of unsteady combustion. A dependence of the burning rate on the burning surface curvature is found. It is demonstrated that there exists a limiting surface curvature value above which self-sustained combustion is impossible. This limiting curvature depends on thermophysical and ballistic characteristics of CEMs. The existence of the limiting curvature of the burning surface offers an explanation of the critical conditions of combustion of homogeneous CEMs. Based on this hypothesis, the critical diameters of combustion of several homogeneous CEMs are calculated. The calculated results are in good agreement with available experimental data.