Erosive Effect on the Burning Rate of Multi-perforation Propellants in Closed Bomb Test

Closed bomb test is a conventional method to determine the combustion performance of propellant. The burning rate pressure exponent for multi-perforation granular propellants is usually lower than single-perforation-cylinder propellants in the test. In this paper, the reason of this phenomenon was analyzed and validated by the test using the same composition but different shapes of propellants. The result shows that the erosive buming will decrease surface area of propellants than the theoretic area according to the geometry buming law while the propellant is burning. This discrepancy is the primary reason for the difference of closed bomb test results.