Hypersonic Prandtl-Meyer Expansion Wave Calculator

– Hypersonic and High-Temperature Gas Dynamics, John D. Anderson, Jr.

This calculator evaluates the deflection angle for Prandtl-Meyer expansion waves in hypersonic flows. It uses an approximate relation, which becomes more accurate as the Mach numbers (M1 and M2​) increase. The formula helps determine the change in the direction of flow due to expansion, which is vital in high-speed aerodynamics where flow expansion waves play a significant role in reducing pressure and temperature downstream of the wave. The flow through an expansion wave is isentropic, making this relation important for designing efficient nozzles and airfoils in hypersonic regimes.

Symbols:

• θ: Flow deflection angle (radians)
• M1​: Freestream Mach number before the expansion wave (dimensionless)
• M2: Mach number after the expansion wave (dimensionless)
• γ: Ratio of specific heats (dimensionless)