爆轰波通过扩张喷管的双曝光全息实验和数值研究

结合实验和数值模拟方法，对以脉冲爆轰发动机为背景的爆轰波通过扩张喷管的流动进行了系列研究。实验采用双曝光全息干涉方法对爆轰波绕射流场进行测量，得到了比传统的纹影法更清晰和可定量化的照片。发展了基于非结构四边形网格自适应有限体积程序,结合基元化学反应模型对扩张喷管中爆轰化学反应流场进行了数值模拟，模拟结果与实验照片吻合较好。实验和数值模拟结果表明,爆轰波绕射具有许多和激波绕射不同的流场特征，其中包括二次起爆现象、化学反应面与前导激波相脱离而引起的复杂流场等，同时初始压力和扩张角度变化也对爆轰波绕射过程产生较大影响，初始压力越低，化学反应区和前导激波分离现象越明显，且前导激波的曲率越大。

Experimental and numerical investigation of gaseous detonation diffraction through a divergent nozzle based on double exposure holography

An investigation of detonation wave diffraction over a divergent nozzle was carried out experimentally and numerically. The experiment was conducted in a detonation tube with double exposure holographic interferometric measurement, which offers better resolution and quantitative information as well, in comparison with conventional flow visualization such as schilieren method. Adaptive finite volume method combined with kinetic chemical reaction model was programmed to simulate the flow field. The numerical results agree fairly well with the experimental measurements. It was found that detonation diffraction has quite a lot of flow feature compared with shock wave diffraction, including the detachment of reaction front and leading shock wave and reignition phenomena. The divergent angle and initial pressure have great influence to the flow field of detonation diffraction. The lower initial pressure, the earlier the detachment of chemical reaction front and leading shock wave will happen.