论文标题
关于传播冲击波与蒸发水滴之间的相互作用
On the interactions between a propagating shock wave and evaporating water droplets
论文作者
论文摘要
进行了基于混合欧拉 - 拉格朗日式方法的一维数值模拟，以研究传播冲击波与分散的两相气doplet流中的蒸发水滴之间的相互作用。采用用于质量，动量和能量的质量，动量和能量的双向耦合。通过考虑各种初始液滴直径（5-20μm），数量密度（2.5 x 1011-2 x 1012 1/m3）和入射冲击马赫数（1.17-1.9），进行了有关冲击衰减，液滴蒸发，运动和加热的参数研究。发现当液滴体积分数较大并且/或入射冲击马赫数较低时，可能会使领先的冲击降低到声波，甚至亚音速波。领先冲击的强度和繁殖速度的衰减主要是由于动量转移到冲击阵线相互作用的液滴引起的。在蒸发区域观察到总压力恢复，而压力损失是由于冲击压缩，液滴阻力和冲击前后压力梯度力的原因。当以下压缩波是超音速时，观察到领先冲击和两相接触表面之间区域的重新压缩。临界点之后，该区域的宽度和相间交换在质量，动量和能量方面变得稳定。然而，重压现象对液滴体积分数很敏感，并且可能会随着液滴负荷而消失。对于入射冲击马赫的1.6，仅当初始液滴体积分数低于3.28 x 10-5时才会发生重新压缩。
One-dimensional numerical simulations based on hybrid Eulerian-Lagrangian approach are performed to investigate the interactions between propagating shock waves and dispersed evaporating water droplets in two-phase gas-droplet flows. Two-way coupling for interphase exchanges of mass, momentum and energy is adopted. Parametric study on shock attenuation, droplet evaporation, motion and heating is conducted, through considering various initial droplet diameters (5-20 μm), number densities (2.5 x 1011 - 2 x 1012 1/m3) and incident shock Mach numbers (1.17-1.9). It is found that the leading shock may be attenuated to sonic wave and even subsonic wave when droplet volume fraction is large and/or incident shock Mach number is low. Attenuation in both strength and propagation speed of the leading shock is mainly caused by momentum transfer to the droplets that interact at the shock front. Total pressure recovery is observed in the evaporation region, whereas pressure loss results from shock compression, droplet drag and pressure gradient force behind the shock front. Recompression of the region between the leading shock and two-phase contact surface is observed when the following compression wave is supersonic. After a critical point, this region gets stable in width and interphase exchanges in mass, momentum, and energy. However, the recompression phenomenon is sensitive to droplet volume fraction and may vanish with high droplet loading. For an incident shock Mach number of 1.6, recompression only occurs when the initial droplet volume fraction is below 3.28 x 10-5.
