Pressure Distribution over a Nose Cap for Flush Air Data System Calibration using CFD Technique at Supersonic Mach Numbers

摘要

Accurate measurement of airdata is critical for the flight control and guidance of atmospheric flight vehicles. The airdata state can be described by Mach number (M), angle of attack (α), side slip angle (β), free stream static pressure and true air speed. For winged Reusable Launch Vehicles (RLV), usage of intrusive conventional airdata measurement systems are highly undesirable, due to high aerodynamic heating during re-entry. So, Flush Air-Data Sensing (FADS) system which relies on a mathematical model relating the forebody surface pressures and the airdata state is envisaged. In the present work, CFD simulations have been carried out on the forebody of a typical RLV. The coefficient of pressure on nose cap has been computed at nine ports at supersonic Mach numbers for FADS calibration. Aerodynamic models for coefficient of pressure as functions of Mach number and angle of attack have been obtained. Shock and flow separation regions on the forebody have been identified.