Oblique detonations induced by semi-infinite wedge are simulated by solving Euler equations with chain branching kinetics. Numerical results show the initiation can be triggered by either the abrupt transition or smooth transition, dependent on incident Ma M_(in) and wedge angle 9, and then their effects on the oblique detonation angle β and initiation length L_(ini) are analyzed. When θ increases, L_(ini) decreases monotonically but p has a minimum value, corresponding to θ = 29° in this study. When M_(in) decreases, both L_(ini) and β increases monotonically until M_(in) decreases below certain critical value, M_(in) = 9.2 in this study. Then low inflow Ma effects generate the maximum L_(ini), with the complex of ODW (oblique detonation wave), SODW (secondary oblique detonation wave) and SIDW (self-ignition deflagration wave). The transient process is observed, demonstrating the structure can self-adjust to find a proper position. The wave structure suggests two wave/heat release process determining the detonation initiation. In the cases with high M_(in) featured by SIDW, the oblique-shock induced self-ignition dominates, and L_(ini) increases when M_(in) decreases. In the cases with low M_(in) featured by SODW, the interaction of ODW and SODW dominates, and L_(ini) decreases when M_(in) decreases.
展开▼
