Abstract
A genuinely three-dimensional spacetime conservation element and solution element (CE/SE) scheme is built as simple, consistent and straightforward extensions of an improved high resolution 2D CE/SE scheme. It is applied to examine the mechanism of three-dimensional detonation process in rectangular ducts. The simulations clearly show detailed three-dimensional detonation modes, namely a rectangular mode and a diagonal mode. Furthermore, the formation of unreacted pockets with high density and low temperature behind the detonation is observed for the two modes.