Turbulence and Vortex Interactions with Shock Waves

该研究项目旨在实验研究激波首先与均匀/各向同性流动的相互作用，然后在所谓的涡量模式下与纵向或横向涡旋的相互作用。具体地说，研究重点将集中在非定常激波在流动中传播时的湍流和涡度放大现象以及湍流或涡旋对激波的扭曲/变形。在激波管内形成的激波穿过网格，激波后的诱导流具有自由流湍流的可压缩流动的特征。衰变的湍流与反射激波相互作用，并以相反的方向运动。在涡/激波干扰中，入射时绕过横向圆柱或小三角翼的诱导流动将分别产生所需的横向涡量或纵向涡量。初步结果表明，在与相同强度的激波相互作用过程中，对于所研究的所有湍流强度和长度尺度，湍流放大并不相同。具有独特特点的拟议课程将为一些机械工程专业的少数族裔学生提供参加一个高级研究项目的机会，该项目旨在更好地了解可压缩湍流。少数族裔学生将接触到最先进的实验和计算技术，因此将被鼓励进入研究职业生涯。

This research project is designed to investigate experimentally the interaction of a shock wave first with homogeneous/isotropic flow and second with a longitudinal or traverse vortex in the so called vorticity mode. Specifically, the research will focus on the phenomenon of turbulence and vorticity amplification across an unsteady shock propagating inside the flow and the distortion/deformation of the shock by turbulence or vortex. A shock wave which is formed inside a shock tube, passes through a grid and the induced flow behind the shock has the features of a compressible flow with free stream turbulence. The decaying turbulence is subjected to interaction with the reflected shock and travelling in the opposite direction. In the vortex/shock wave interaction, the induced flow over a transverse circular cylinder or a small delta wing at incident will generate the required vortices with transverse or longitudinal vorticity respectively. Preliminary results indicate that turbulence amplification is not the same for all investigated turbulence intensities and length scales during interactions with the shock waves of the same strength. The proposed program with its unique characteristics will provide the opportunity to a number of minority students in Mechanical Engineering to participate in an advanced research project aimed at a better understanding of compressible turbulence. Minority students will be exposed to the-state-of-the-art in experimental and computational techniques and, therefore, will be encouraged to enter research careers.