The HyShot Scramjet Flight Experiment - Flight Data and CFD Calculations Compared

Abstract

An analysis has been made using CFD of selected points on the HyShot scramjet flight experiment trajectory. Two-dimensional intake calculations have been done to assess the influence of angle of attack on the performance of the intake and cowl shock/boundary layer bleed duct, and have shown that at low angles of attack the configuration is well behaved, but at high angles of attack the cowl shock separates the boundary layer on the main intake ramp. This sends a separation shock into the combustion chamber. For selected altitudes during the flight for which the maximum angle of attack is a local minimum and for which there is zero yaw, intake and combustor calculations have been made. The calculations consistently predict that supersonic combustion has been obtained. At higher altituudes, reasonable agreement between the measured and predicted pressures is found, although the fuel-off pressures are underpredicted by approximately 15%. At lower altitude, further into the experiment, the flight data is well underpredicted. Further investigations of the flight data are required to assess this, including the possibility of leading edge ablation and/or intake distortion due to the high flight heat loads.