弹丸速度对超爆轰冲压加速器性能影响

Influences of Projectile Velocity on Performance of Super-Detonative Ram Accelerator

为研究超爆轰模态冲压加速器的推进性能,采用混合的Roe/HLL(Harten,Lax,Van Leer)格式,结合自适应网格加密技术(AMR)与沉浸边界法(IBM),数值模拟了弹丸速度高于预混可燃气体C-J爆速的冲压加速器流场,揭示了弹丸速度对流场结构与推力的影响。结果表明当弹丸速度在一定范围时,斜爆轰波可驻定在弹丸肩部或头部,在弹丸尾部形成高压区加速弹丸,并且,斜爆轰波驻定在弹丸头部推力更高,稳定工作的速度范围更宽。

To investigate the propulsion performance of a super-detonative ram accelerator, the hybrid Roe/HLL （Harten, Lax, Van Leer） scheme, the adaptive mesh refinement （AMR） technique and immersed boundary method （IBM） are employed, and the flow-field of a ram accelerator with the projectile velocity greater than the C-J detonation velocity of the combustible gas is simulated numerically. The influence of the projectile velocity on the flowfield structures and thrust is revealed. It shows that if the projectile velocity is within a proper range, the oblique detonation wave appears and stays stable at the shoulder or head of the projectile, at this time the projectile is steadily accelerated under the action of the high pressure of the back part and bottom of the projectile. In addition, when the oblique detonation wave stays at the head of the projectile, the thrust is higher and the velocity range of the steady acceleration becomes wider.