Using Surface Grooves on Propellant Grain to Control the Erosive Burning in Solid Rocket Motors

Abstract

This paper aims to introduce a new technique to eliminate the erosive burning phenomenon in solid rocket motors. The erosive burning which occurs in motors with high volumetric loadings and small port to throat area ratios, has some disadvantages like an early phase over‐pressure and exposing the rocket chamber casing by hot combustion gas flows. The innovative simple practical method is based on the geometrical treatment of the propellant grain, locating some grooves on the surface at its aft‐end, to reduce the rate of the heat transfer into the burning surface where the erosive burning is likely to occur. The numerical analysis of the flow on the grooved wall is utilized to physically explain the correctness of this idea, and the quasi‐one‐dimensional simulation of the internal ballistics of the solid rocket motor is performed to demonstrate the effect of grooves on the performance map of the motor. The results show that by using this suggested simple technique, the designer can eliminate the erosive burning and improve the motor‘s performance maps.

Using Wavy Fuel Surface to Improve the Performance of the Solid Fuel Ramjets

“…Therefore, the practical heat transfer augmentation techniques may be a candidate to be utilized for SFRJ performance improvement. Such an innovative technique based on the heat transfer change has also been proposed recently for specific improvement in the rocket propulsion systems [9], where the erosive burning is decreased by using some grooves on the solid propellant, and the initial over‐pressure of the motor is controlled.…”