2-D Simulation with OH* Kinetics of a Single-Cycle Pulse Detonation Engine

Two-dimensional computational fluid dynamics (CFD) simulation with selected kinetics for H2–air mixture of a hydrogen-fuelled single-pulse detonation engine were performed through ANSYS FLUENT commercial software for diagnostic purposes. The results were compared with Chapman–Jouguet (CJ) values calculated by the CEA (Chemical Equilibrium with Applications) and ZND (Zel’dovich–Neumann–Döring) codes. The CJ velocities and pressures, as the product velocities are in agreement, however, the CJ temperatures are too higher for 2-D simulations; as a consequence, the sound velocities were overpredicted. OH* kinetics added to the reaction set allowed visualization of the propagation front with several detonation cells showing a consistent multi-headed detonation propagating in the whole tube. The detonation front was slightly perturbed at the end of the tube with inclination of front edge and fewer cell numbers, and more significantly at the nozzle entrance with velocity reduction, resulting in a weak and unstable detonation. OH* images showed the detonation reaction zone decoupled from the shock front with disappearance of cellular structure. The inclusion of OH* reaction set for CFD simulation coupled to kinetics is demonstrated to be an excellent tool to follow the detonation propagation behaviour.