Determination of Effective Crossover Location and Dimensions for Branched Detonation in a Pulsed Detonation Engine

A study is presented of the optimal crossover duct location and width to obtain consistent branched detonation transition from one detonation tube to another. On a Pulsed Detonation Engine (PDE) with detonation branching, the duct location at which the detonation crosses from one (primary) tube to a branched (secondary) tube impacts the number of successful detonations. In this paper, a comparison is made of the effects of the location and width of the crossover duct for hydrogen, ethylene and an n-alkane. The crossover location is varied from the aft end of the detonation tube to the middle of the detonation tube while the crossover width is varied from 2.5 in to 0.5 in. Detonation wave speeds are measured and compared to Chapman-Jouguet velocities in order to determine successful detonations. Regardless of crossover location, all three fuels are demonstrated 100% of the time to transition between 2 in detonation tubes with a crossover width of 2 in. With a mid-location crossover duct, all three fuels are demonstrated 100% of the time to transition detonations between 2 in detonation tubes with a crossover width between 1.75 in and 2.5 in. The original document contains color images.