Transient Chamber Flowfield Simulation of a Rod-and-Tube Configuration Solid Rocket Motor

A transient CFD simulation of the flowfield within a rod-and-tube solid propellant rocket motor has been developed. This model couples the fluid dynamics and heat transfer of the gas flowfield within the rocket port to the nozzle to predict the internal environment within the motor including the regression rate of the propellant. The propellant regression is described with an empirical erosive burning model based on the phenomenological heat transfer approach derived by Lenoir and Robillard 1 . The predicted propellant burn rate and consequently the chamber pressure were found to be significantly increased from the case where propellant regression was described by the simple burning law only. This augmentation of the burn rate, particularly during the early stages of the simulation, was in agreement with the trends observed in small diameter rockets where erosive burning was present. A validation of the model comparing an actual Pressure - Time plot to that predicted by the CFD model was also carried out and achieved a very high degree of correlation.