Interaction of Decaying Freestream Turbulence with a Moving Shock Wave: Pressure Field
Interaction of Decaying Freestream Turbulence with a Moving Shock Wave: Pressure Field
复制标题
衰减自由流湍流与移动冲击波的相互作用：压力场
DOI：
10.2514/2.6066
复制
发表时间：
2002
影响因子：
1.9
通讯作者：
Y. Andreopoulos
中科院分区：
文献类型：
--
作者：
S. Xanthos;G. Briassulis;Y. Andreopoulos
在大型激波管装置上，采用不同尺寸的矩形网格，对运动激波与近湍流、各向同性衰减可压缩湍流的非定常相互作用进行了实验研究。用具有时间和空间分辨率的仪器测量了激波管内的速度、总压、温度和激波管壁的静压，研究了激波管壁与激波管壁的相互作用。激波强度的衰减是由于激波与湍流场相互作用的结果，它取决于网格的网格尺寸或雷诺数、低马赫数和激波的初始马赫数。在相同马赫数下，细网格产生的紊流比粗网格对激波的衰减更大。在所有的实验中都观察到了相互作用后压力波动的放大，这取决于网格尺寸（初始扰动水平）和激波强度。此外，在所分辨的整个波数范围内，这种分离是不相同的。I.引言由于非定常流动现象，涡轮机的涡轮或压气机内部会产生激波或膨胀波。这些移动的波可以与旋转或静止的叶片以及气流相互作用，并且可以导致可以影响发动机的操作和性能的现象。这些现象之一是通过激波与湍流的相互作用。对于那些研究湍流的人来说，特别感兴趣的是行进冲击波与自由湍流的相互作用，这可以被认为是近似各向同性和近似均匀的。一般说来，激波与湍流的相互作用在工程应用的外部或内部空气动力学中具有重要的实际意义，因为它们通过涡量和熵的产生和输运而显著地改变流体场。最近Andreopoulosetal审查了过去的工作。1的结果表明，激波与湍流之间的相互作用是相互的，两者之间的耦合是很强的。涉及复杂的线性和非线性机制，可以引起湍流结构及其统计特性的显著变化，并改变冲击波运动的动力学。激波与湍流相互作用的最重要结果是速度脉动的放大和长度尺度的显著变化。这表明这种相互作用可能会极大地影响混合。例如，Budzinski等人提出使用冲击波作为增强混合的手段
Theunsteady interaction of a moving shock wavewith nearly homogeneousand isotropic decaying compressible turbulence has been studied experimentally in a large-scale shock-tube facility by using rectangular grids of various sizes. The interaction has been investigated by measuring velocity, total pressure, and temperature inside thee owe eldandstaticpressureatthewalloftheshocktubewithinstrumentationoftemporalandspatialresolution. Attenuation of theshock wavestrength has been found to take placeas a result oftheinteraction with theturbulent e owe eld, which depends on the mesh size of the grid or its Reynolds number, the e ow Mach number, and the initial Mach number of the shock wave. Finer grids produce turbulence, which attenuates the shock wave more than coarse grids at the same Mach number. Amplie cation of pressure e uctuations after the interaction has been observed in all experiments, depending on grid size (initial turbulencelevel )and shock strength. Furthermore, this amplie cation is not the same through the whole range of wave numbers resolved. I. Introduction T RAVELINGshockwavesorexpansionwavescanbegenerated inside turbines or compressors of turbine engines as a result of unsteady e ow phenomena. These moving waves can interact with rotating or stationary blades, as well as with the e ow, and may result in phenomena that can affect the operation and performance of the engine. One of these phenomena is the interaction of passing shock waves with turbulence. Of particular interest to those studying turbomachinery is the interaction of traveling shock waves with freestream turbulence, which can be considered as nearly isotropic and nearly homogeneous. In general, interactions of shock waves with turbulent e ows are of great practical importance in external or internal aerodynamics of engineering applications because they considerably modify the e uid e eld by vorticity and entropy production and transport. PastworkthathasbeenrecentlyreviewedbyAndreopoulosetal. 1 hasshownthattheinteractionbetweentheshockwaveandturbulent e ow is mutual and that the coupling between them is very strong. Complex linear and nonlinear mechanisms are involved that can cause considerable changes in the structure of turbulence and its statistical properties and alter the dynamics of the shock wave motion. Amplie cation of velocity e uctuations and substantial changes in length scales are the most important outcomes of interactions of shock waves with turbulence. This indicates that such interactions may greatly affect mixing. The use of shock waves, for instance, has been proposed by Budzinski et al. 2 as means to enhance mixing