aerothermodynamics

Aerothermodynamics is the study of the interaction between aerodynamic and thermodynamic processes in high-speed flows. It examines how velocity, pressure, temperature, and heat transfer influence the performance, stability, and structural integrity of aerospace vehicles operating at Mach numbers where compressibility and heating are significant.

Key concepts include compressible flow, shock waves, boundary layers, and the transport of energy within a gas. Stagnation properties such as the stagnation temperature and stagnation pressure describe the conditions of a fluid that is brought to rest isentropically, with T0 = T (1 + (gamma−1)/2 M^2) and P0 = P [1 + (gamma−1)/2 M^2]^(gamma/(gamma−1)).

Aerodynamic heating raises material temperatures and drives the design of thermal protection systems. Heating can be convective or radiative, and is especially severe for blunt bodies at hypersonic speeds. Materials, ablation, and cooling strategies determine survivability during entry or ascent.

Governing equations combine fluid dynamics and thermodynamics: the compressible Navier–Stokes equations with an energy equation and an appropriate equation of state. Real gas effects, chemical reactions, and radiation may be important at high temperatures. Analysis relies on analytical methods, computational fluid dynamics, and experimental facilities such as wind tunnels and shock tubes.

Applications include atmospheric reentry and descent of spacecraft, hypersonic transport and missiles, scramjets, and other high-speed flight regimes where aerodynamic forces and heating dominate design decisions.