液体薄层界面不稳定性和湍流混合实验研究

The Rayleigh-Taylor instability occurs at the interface between a heavy fluid overlying a light fluid or a light fluid accelerates a heavy fluid , the Richtmyer-Meshkov instability occurs when a perturbed interface between two fluids of differing densities is impulsively accelerated，they are of fundamental importance in a multitude of applications ranging from ICF to astrophysics and to ocean and atmosphere dynamics. Most of the theoretical,computational,and expe- rimental work of hydrodynamics instability has been in large measure two fluids,about fluid layer is few.For the Rayleigh-Taylor instability of fluid layer, experiments are perform on the gas-fluid interface with a complex acceleration history consisting of consecutive periods of acceleration, deceleration, and acceleration, for the Richtmyer-Meshkov instability of fluid layer，the interface is accelerated by a Mach number > 1.3 planar shock wave, and the development of the ensuing turbulent mixing layer is investigated using planar laser induced fluorescence,PIV and Shadowgraph imaging.An understanding of the shock-induced and vortex generation is vital to the future study of interface break up and turbulent mixing by hydrodynamics instability.

当轻流体支撑重流体或轻流体加速重流体时产生Rayleigh-Taylor不稳定，当激波脉冲加速不同密度流体的扰动界面时产生Richtmyer-Meshkov不稳定性，这些不稳定性在ICF(惯性约束聚变)、天体物理、海洋和大气运动等广泛的领域具有应用和重要的作用。流体动力学界面不稳定性的理论、计算和实验工作大都是建立在两个无限域流体上，而对于液体薄层的不稳定性问题研究较少。针对流体薄层Rayleigh-Taylor不稳定性，实验研究气－液界面在加速、减速、加速周期复杂加速过程的不稳定性；液体薄层Richtmyer-Meshkov不稳定性由马赫数大于1.3的平面激波冲击加速界面得到，界面的演化以及发展后的湍流混合层通过平面激光荧光，PIV和阴影等技术测试得到。在流体动力学界面不稳定性诱导的界面破碎和湍流混合的研究中，深化对激波作用和涡产生机理的认识和理解。

当轻流体支撑重流体或轻流体加速重流体时产生Rayleigh-Taylor不稳定，当激波脉冲加速不同密度流体的扰动界面时产生Richtmyer-Meshkov不稳定性，这些不稳定性在ICF(惯性约束聚变)、天体物理、海洋和大气运动等广泛的领域具有应用和重要的作用。针对流体薄层Rayleigh-Taylor不稳定性，实验研究界面在加速、减速、加速周期复杂加速过程的不稳定性，对Richtmyer-Meshkov不稳定性由马赫数大于1.3的平面激波冲击加速界面得到，界面的演化以及发展后的湍流混合层通过平面激光荧光，PIV和阴影等技术测试得到。在水平激波管中利用马赫数为 1.2 的激波对竖直方向上间距为 4mm 的多根直径为 2mm 的液柱进行冲击，利用阴影法记录了多根液柱变形破碎的过程，对得到的实验结果进行了定量分析， 得到了在激波作用下不同根数液柱之间的变化差异。 利用多相流 VOF 模型和 k-ε湍流模型，对实验过程进行了数值模拟，得到了激波与液柱相互作用过程中液柱及周围流场的物理特性。在流体动力学界面不稳定性诱导的界面破碎和湍流混合的研究中，深化对激波作用和涡产生机理的认识和理解。