Calibration for the FADS system applied to the vehicle with blunt fore-bodies

Based on the wind tunnel pressure data of a l/7-scale model of the F-14 airplane, three parameters of the FADS (Flush Air Data Sensing System,FADS)system,the angle-of-at-tack flow correction angle,the angle-of-sideslip flow correction angle,and the shape and com-pressibility parameter,were calibrated for applying to the vehicle with blunt fore-bodies.The wind-tunnel test Mach numbers were 0.73,0.90,1.05,1.20,and 1.39.Angles of attack were varied in 2°increments from -4°to 20°.Sideslip angles were varied in 2°increments from -8 ° to 8°.The calibration results show that different pressure points have great influence on the cali-bration of the angle-of-attack flow correction angle and the angle-of-sideslip flow correction angle based on the triple algorithm.And the best calibration results can be determined by the pressure points in a symmetrical configuration about the stagnation pressure point.And the calibration for the angle-of-attack flow correction angle is independent of the calibration for the angle-of-sideslip flow correction angle.As to the shape and compressibility parameter,it is related to the effective angle of attack,the effective angle of sideslip,the Mach number,the vehicle shape and other sys-tem factors.With the Mach number increases,the value of the shape and compressibility param-eter tends to zero .