Reusable thermal protection systems are one of the key technologies that have to be improved to use hypersonic vehicles as practical, long-range, transportation systems. The proposed concept of variable-transpiration cooling is investigated in this work by coupling the hypersonic boundary-layer solution with the thermal response of a porous material. The simulations of the hypersonic boundary layers are obtained using an in-house-developed reduced-order model capable of handling generic injection velocity profiles at the porous wall and the high-fidelity computational-fluid-dynamics code Langley Aerothermodynamic Upwind Relaxation Algorithm. The material thermal response is included adopting a one-dimensional model for the porous medium. The integrated analysis is performed for a flat plate and a two-dimensional blunt-body configuration. A sawtooth wall velocity profile was chosen to represent the variable-transpiration strategy. The uniform transpiration on the blunt body allows for a reduction of the stagnation point heat flux by 48% in comparison with the case without transpiration. The variable transpiration reduces the stagnation point heat flux by an additional 8%. The integrated analysis highlights the coolant blockage effects, the potential offered by the variable-transpiration cooling, and the necessity of performing a coupled flow-material analysis, at the design stage, to define realizable combinations of porosity, thermal conductivity, and material thickness capable to guarantee the thermostructural integrity of the thermal protection system.
- Algorithms,
- Computer Simulation,
- Cooling,
- Heat Flux,
- Heat Shielding,
- Heating,
- Hypersonic Flow,
- Hypersonic Vehicles,
- Porous Materials,
- Thermal Insulating Materials,
- Transpiration,
- Boundary-Layer Solution,
- Integrated Analysis,
- One-Dimensional Model,
- Reduced Order Models,
- Relaxation Algorithm,
- Stagnation Point Heat Fluxes,
- Thermal Protection System,
- Transportation System,
- Thermal Conductivity
Available at: http://works.bepress.com/serhat-hosder/55/