Aerothermics

Aerothermics is the study of heat transfer and energy exchange in moving gases, particularly air, and its interaction with solid surfaces in aerodynamic environments. It combines principles from aerodynamics, thermodynamics, and heat transfer to analyze how high-speed flows heat or cool bodies and how surfaces respond thermally.

Key phenomena include compressible heating due to shock waves and viscous dissipation, boundary-layer development, and heat flux to surfaces. Concepts such as stagnation temperature, total temperature, and convective heat transfer coefficients are used to estimate aeroheating. In some contexts radiative heat transfer becomes significant at very high temperatures, such as during atmospheric re-entry.

Applications are most prominent in aerospace engineering. Aeroheating considerations drive the design of thermal protection systems for spacecraft and re-entry capsules, high-speed missiles, and hypersonic aircraft. The goal is to manage heat loads to protect structural integrity and mission success. The working fluid is air or other atmospheric gases, though the underlying methods apply to any compressible gas.

Methodologies include solving the compressible Navier–Stokes equations with an energy equation, often via computational fluid dynamics (CFD), and using simplified analytical or semi-empirical correlations for quick estimates. Experimental approaches employ high-enthalpy wind tunnels, arc-jet and plasma jet facilities, and calorimetry to measure surface temperatures and heat fluxes.

Aerothermics intersects with materials science, particularly in designing heat shields and ablative or insulative materials, and with plasma physics in cases of high-temperature dissociation and radiation. Current research addresses hypersonic flight, thermal protection system reliability, radiation at high temperatures, and coupled thermo-mechanical responses of structures under aeroheating.