Extended Application and Experimental Verification of a New Erosive Burning Model Coupled Heat Transfer between Gas and Grain Based on a Star-Grain Solid Rocket Motor

The estimation of erosive burning is of great importance for the internal ballistics computation of a solid rocket motor (SRM) with a large aspect ratio. Because of the variety of parameters affecting erosive burning, most of the erosive burning models developed in earlier years usually contain unknown constants that need to be identified by a trial-and-error procedure for each SRM. Based on an SRM with a cylindrical grain, a new erosive burning model, which coupled the heat transfer between the gas and grain, was proven to be effective previously. To expand the scope of application of this model, in this paper, earlier and new erosive burning models were used in the transient one-dimensional internal ballistics computation, to obtain the internal ballistics for a star-grain SRM. A comparison between the computational and experimental results indicated that both the earlier and new erosive burning models can obtain results with good accuracy for a star-grain SRM. The paper shows that with no constants to be identified, the Ma model is easy to use and has the potential to predict the erosive burning rate before a firing test.