On the validation of high enthalpy wind tunnel simulations

Ln the frame of the Ground-to-Flight Transposition methodology for reentry vehicles, Europe has built high enthalpy facilities, the ONERA hot shot wind tunnel F4 and the DLR piston driven shock tube wind tunnel HEG. Both facilities can provide flows at high velocity (5 to 6 km/s) and at high reservoir pressure (several hundreds atmospheres). These facilities are operational since a few years. Despite technological difficulties attached to high thermal loads, they have allowed to study topics of great importance in hypersonics, such as the influence of real gas (i.e. high temperature gas with thermochemistry) on flare-induced boundary layer separation. After discussing on the Ground-to-Flight Transposition methodology in hypersonics, the F4 wind tunnel is presented. Finally, the problem of the Validation of high enthalpy wind tunnel experiments is discussed through the analysis of typical experimental results and of the related rebuilding computations. (C) Elsevier, Paris.