The Use of Fractal for Prediction of Burning Rate of Composite Solid Propellants

By using the fractal geometry it is possible to calculate the actual AP (Ammonium Perchlorate) surface area and oxidizer-binder interface fractal dimension in the prediction of burning rate of composite solid propellants. In this investigation, the fractal dimension was determined by a procedure known as the "Box Counting Method". Using this dimension, surface area relations were developed for the rough particles. This method was implemented in the PEM (Petite Ensemble Model) burning rate model. The comparison of burning rates for a typical propellant by the PEM and fractal model shows that the burning rates obtained by using the fractal geometry are slightly less than those obtained by the PEM model.