Expert Thermal Management Architecture and Aerothermal Aspects 2005-01-2900

Activities performed during the phase B of the EXPERT capsule highlighted tight coupling between design solutions outlined for the thermal management architecture and the aerothermal phenomena expected during the re-entry trajectory.

Ceramic and high temperature resistant metallic Thermal Protection System (TPS) form the aerodynamic shape of the capsule, so contributing to the aerothermal and structural flight verification, and also accomplish system functions, as TPS is part of a thermo-mechanical architecture that has to ensure the integrity of the capsule.

Typical aerothermal phenomena to be tested, such as laminar to turbulent transition, roughness effects, active oxidation and catalycity, need a synergistic coupling with the TPS design called to play an active part during the experimentation (materials characteristics affect and are influenced by aerothermodynamics). A multidisciplinary approach investigated the effects induced on the aerothermal predictions by the thermal capacities of the TPS during the re-entry heating. The TPS Outer Mold Line (OML) adiabatic equilibrium temperature obtained as a result of a first-step CFD simulation was then updated on the basis of its remarkable decreases derived by the heat sink effect associated to the metallic TPS thickness, to the insulation located beneath and to the internal environment.

Last, but not the least, phase B system activities also investigated the EXPERT internal environment consequent to the TPS design solutions. Air temperature and pressure determined during the re-entry by the heat flux passing through the TPS and by the venting system are deeply analyzed to achieve a congruent architecture including TPS and Thermal Control System (TCS) able to satisfy aerothermal needs too.