Aerothermodynamics and Heat Transfer

Aerodynamics studies at very high speeds must account for heat transfer phenomena in the fluid, as well as for significant thermal effects in gas-solid interfaces.


Drag reduction in supersonic flight:

Aerodynamic heating increases significantly with flight Mach number.as more kinetic energy is converted into heat via compression and friction. For example, across shock waves the density, pressure and temperature of the fluid rise strongly. In addition, due to the entropy increase across the shock, which is equivalent to a loss of total pressure, the wave drag contribution becomes important. This affects the trade-off between wave drag and other forms of aerodynamic drag in new supersonic transport aircraft incorporating laminar flow technology.



Wall cooling effectiveness:

Cooling effectiveness is very important when significant heat transfer takes place in gas-solid interfaces. This may occur as a consequence of aerodynamic heating at high speeds, but also at low air speeds in the presence of streams with very different temperatures and low momentum ratio. For example, in order to protect the integrity of high-pressure gas turbine components, film-cooling is applied and a maximization of the cooling effectiveness is desired.




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