文档介绍：CHAPTER 9 OBLIQUE SHOCK AND EXPANSION WAVES
斜激波和膨胀波
引言
第八章我们讨论了正激波, 本章我们讨论斜激波, 及超音速流场中的另一个重要特征——膨胀波。
Wave angle: 激波角, 激波与激波上游来流的夹角。
A normal shock wave is simply a special case of the general family of oblique shocks, namely, the case where the wave angle is 900.
β
Across the oblique shock wave, the Mach number discontinuously decreases, and the pressure, density, and temperature discontinuously increase.
θ: Deflection angle (偏转角)
Across the expansion wave, the Mach number continuously increases, and the pressure, density, and temperature continuously decrease.
Hence, an expansion wave is the direct antithesis of a shock wave.
因此,膨胀波是激波的一个正相反的对应物。
Oblique shock and expansion waves are prevalent in two- and three-dimensional supersonic flow. These waves are inherently two-dimensional in nature, in contrast to the one-dimensional normal shock waves discussed in . That is, in Fig. and b, the flow-field properties are a function x and y. The purpose of the present chapter is to determine and study the properties of these oblique waves.
斜激波和膨胀波在二维、三维超音速流动中是很普遍的。这些波在本质上是二维的,与第八章讨论的一维正激波相反。即,,流场特性是x 、 y的函数。本章的目的就是确定和研究这些斜波(斜激波和膨胀波)的性质。
• What is the physical mechanism that creates waves in a supersonic flow? 超音速流中产生波的物理机理是什么?
If the upstream flow is subsonic , as shown in , the disturbances have no problem working their way upstream, thus giv