Investigations on oblique detonations induced by a finite wedge in high altitude

In this paper, the characteristics of two-dimensional (2D) oblique detonation waves (ODWs) induced by finite wedges in high altitude are investigated numerically. The reactive Euler equations with a detailed chemical model are solved. This paper focuses on the effects of expansion waves and altitudes on ODW, including the initiation, wave structures, pressure and temperature distributions. Numerical results demonstrate that both the location of turning point from oblique wedge to horizontal wedge and the altitude influence the initiation characteristics of ODW. Then, the initiation criterion of ODW for finite wedges is proposed in this paper. As the characteristic length of induction zone L-C (the length from the front point of oblique wedge to the front point of deflagration wave) and the characteristic length of oblique wedge L-W satisfy the relationship L-C/L-W > 1, the initiation of ODW occurs. When L-C/L-W < 1, the initiation of ODW doesn't occur. This work would be significant to the designing of oblique detonation engines (ODE) in air-breathing hypersonic vehicle. (C) 2019 Elsevier Masson SAS. All rights reserved.