Longitudinal Aerodynamics of a Winged Reentry Vehicle at Supersonic Speed

摘要

Experiments were carried out to bring out the effects of the single vertical tail (SVT) and the twin vertical tail (TVT) of a typical winged reentry vehicle on aerodynamic coefficients at supersonic speed (M = 2.95) for the range of angles of attack varying from -5 to 25 deg. Toward this, the tunnel was calibrated for the Mach number (flow uniformity) and the flow angularity. As a second level of calibration, experiments were carried out on a standard Experiment Re-Entry Space System reentry model. The results indicated that the obtained aerodynamic coefficients were well within 3% of the literature values. Flowfield studies through schlieren flow visualization illustrated almost similar flow patterns for both SVT and TVT configuration for the tested alpha. However, flow separation on the leeward side at high alpha was observed to be strong in the case of the TVT configuration as compared to the SVT configuration. The aerodynamic coefficients such as C-A, C-N, and L/D for the TVT configuration were 9, 11, and 13% higher than those of the SVT configuration. On the other hand, the SVT configuration was observed to be more stable, whereas mixed stability was seen in the TVT configuration. As far as the stability margin was concerned, the SVT configuration showed the stability margin as high as 33%, whereas the TVT configuration exhibited only a 14% stability margin. Beyond alpha =10 deg, the TVT configuration was found to be neutrally stable.