Prandtl–Meyer Expansion Fan: Convex Set, Mach Wave, Second Law of Thermodynamics - Tapa blanda

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A Prandtl-Meyer expansion fan is a centered expansion process, which turns a supersonic flow around a convex corner. The fan consists of an infinite number of Mach waves, diverging from a sharp corner. In case of a smooth corner, these waves can be extended backwards to meet at a point. Each wave in the expansion fan turns the flow gradually (in small steps). It is physically impossible to turn the flow away from itself through a single shock" wave because it will violate the second law of thermodynamics. Across the expansion fan, the flow accelerates (velocity increases) and the Mach number increases, while the static pressure, temperature and density decrease. Since the process is isentropic, the stagnation properties remain constant across the fan. "