Trajectory based validation of the Shuttle heating environment

Abstract

Chemically reacting,three-dimensional,fullNavier ‐Stokescalculationsaregenerated around theshuttleorbiter and are compared with the STS-2 e ight database at eight trajectory locations. Numerical estimates of quantities necessary for thermal protection system design, surface temperature and heating proe les, integrated heat load, bond-line temperatures, and thermal protection system thicknesses arecompared with theSTS-2 shuttledata. The effects of surface kinetics, turbulence, and grid resolution are investigated. It is concluded that trajectory-based thermal protection system sizing, the use of a Navier ‐Stokes e ow solver combined with a conduction analysis applied over an entry trajectory, is a benee cial tool for future thermal protection system design. This conclusion is based on a reasonable agreement between the e ight data and numerical predictions of surface heat transfer and temperature proe les, integrated heat loads and bond-line temperatures at most of the wind-side thermocouples. Theeffectsofturbulentheating on thermalprotection system designareillustrated.Forfuturelargeentry vehicles, it is concluded that the prediction of turbulent transition will be a major driver in the thermal protection system design process. Finally,onepotential payoff ofusingtrajectory-based thermalprotection system sizing,a reduction in thermal protection system mass, is illustrated. Nomenclature CT = heat transfer coefe cient, W/m 2 -K cp = heat capacity of solid cs