Investigation on the effects of deflector structure on detonation initiation by shock wave focusing

To investigate the effects of depth and angle of deflector on detonation initiation via shock wave focusing in a 2-stage PDE, detonation initiation with different deflector depth and angle was simulated and hydrogen-air mixture was used in this study. The results indicate that a deeper deflector has a favorable effect on detonation initiation and can produce higher temperature and pressure at initiation point. When the deflector angle is small, the operation frequency and the net impulse of the device as a whole per second decrease as the deflector becomes deeper. With the deflector angle increasing, however, a deeper deflector corresponds to higher operation frequency and net impulse. In addition, as the deflector angle increases, both temperature and pressure at initiation point undergo an increase first, obtaining maximal value at 25°, and then followed by decreasing a increasing deflector angle also produces an earlier initiation moment, increase of operation frequency and net impulse.