NAVIER-STOKES SIMULATIONS OF ORBITER AERODYNAMIC CHARACTERISTICS INCLUDING PITCH TRIM AND BODYFLAP

An analysis of the longitudinal aerodynamics of the Shuttle Orbiter in the hypersonic flight regime is made through the use of computational fluid dynamics. Particular attention is given to establishing the cau se of the ''pitching moment anomaly,'' which occurred on the Orbiter's first flight, and to computing the aerodynamics of a complete Orbiter configuration at night conditions. Data from ground-based facilities as well as Orbiter flight data are used to validate the computed resul ts. Analysis shows that the pitching moment anomaly is a real-gas chem istry effect that was not simulated in ground-based. facilities, which used air as a test gas. Computed flight aerodynamics for the Orbiter are within 5 % of the measured flight values and trim bodyflap deflect ions are predicted to within 10%.