Abstract: To provide an insight into the instability of oblique detonation waves and the evolution law of cellular-like structures, a numerical study on the curvature effect of wedge induced oblique detonation waves is conducted with different chemical kinetic parameters (heat release quality, heat release ratio and reference lengths of chemical reaction zones). The solver based on the Weighted Essentially Non-Oscillatory (WENO) scheme processed spatial discretization and additive Runge-Kutta method processed time discretization is used here. The numerical results show that the trend of the wave angles along the oblique detonation wave front can be divided into three regions: Region I, where the wave angles decrease smoothly; Region II, in which the wave angles experience a steep increase first and followed then by decay; Region III, where the wave angles exhibit an oscillation. The normal velocity-curvature relation in Region I is a quasi-vertical line with the flow field being a decaying oblique detonation wave. A "D" shaped curve consisting of a polar line, a smooth horizon curve and a quasilinear curve can be found in the normal velocity-curvature diagram for Region III, where a cycle evolution of cellular-like structures occurs in the front. Region II is deemed as the coupling effect of Regions I and III. Different chemical kinetic parameters bring diverse effects on the oblique detonation wave front.

Key words: numerical simulation, oblique detonation waves, detonation instability, cellular-like structures, wave angles, normal velocity-curvature relations