The oblique detonation wave induced by finite length wedge surface is investigated by numerical simulations. The Euler equations coupled with a two step chemical reaction model are solved. The 5th order WENO scheme is adopted to capture the oblique detonation wave. According to the numerical results, the oblique detonation waves with the wedge length lw = 5 mm and inflow Mach number Ma = 6.5, 7.0 and 7.2 cannot take place spontaneously over the wedge surface. It results from that the induction lengths in these three cases are all larger than the wedge length, 5 mm. To investigate the influence of the initial condition on the formation of the oblique detonation wave, a disturbance is introduced into the non-reacting shock wave induced by the above mentioned wedge surface. The disturbance has an area of 2.0×2.0 mm 2 and contains partially induced hydrogen-air mixture. Resulting from this disturbance, premature ignition takes place over the wedge surface, and results in the formation of the oblique detonation wave. For the cases with Ma = 6.5 and 7.0, the oblique detonation wave propagates forward and stabilizes at the wedge tip. For the case with Ma = 7.2, the oblique detonation wave propagates backward from the initiation point and eventually moves outside the computational domain. The stabilized flow field of the case of Ma = 6.5 shows that the oblique detonation wave only takes place in the vicinity of the wedge surface, and the reaction front decoupled from the oblique shock wave in the far field. The numerical results with the wedge length lw = 5 mm, 7 mm and 9 mm show that the size of the region, within which the reaction front couples with the shock wave, increases with the wedge length lw.
