Numerical Investigation of Pre-detonator Geometries for PDE Applications

A parametric study was performed to determine optimal geometries to allow the successful transition of a detonation from a pre-detonator into the thrust tube of a pulse detonation engine. The study was performed using a two-dimensional Euler solver with progress variables to model the chemistry. The geometrical configurations for the simulations look at the effect of shock reflections, flow obstructions, and detonation diffraction to determine successful geometries. It was observed that there are success and failure rates associated with pre-detonators. These success rates appear to be determined by the transverse wave structure of a stably propagating detonation wave and must be considered in the design and testing of a practical pre-detonator. A simple and straight forward method of estimating the success rate is presented. Desirable effects from geometries with high success rates are used as a basis for recommendations for future pre-detonator designs. The original document contains color images.