测压点分布对嵌入式大气数据传感系统计算精度的影响研究

测压点是嵌入式大气数据传感(FADS)系统的数据来源,其分布形式直接影响到系统测量精度。基于牛顿模型和滤波算法建立FADS计算模型;以球形机头为例,设定飞行剖面的马赫数范围为4.30~15.79,高度范围为25~70km;得出测压点圆周角、圆锥角和非对称分布下大气参数的计算误差。结果表明:沿圆周方向增加测压点数量,可提高FADS系统测量精度,但存在门槛值,超过此门槛值效果有限;在测压点数量相同的情况下,增大圆锥角可明显提高FADS的测量精度;测压点的非对称分布则对测量精度没有影响。

Research of Orifices Distribution Effects onPrecisions of Flush Air Data System

FADS(Flush Air Data System) had been used in various aircraft, showing the advantages of less interference on flow field, thermal and stealth characteristics of the aircraft. Numerical computations based on Newton model and filtering algorithm were conducted to investigate the orifices distribution effects on Accuracies of FADS. Virtual flight path covering Mach number 4.3-15.79, height 25-70 kilometers was defined. Spherical nose was presented for FADS orifices arrangement. Results of clock angle effect, cone angle effect and asymmetric distribution effect were presented and analyzed. Computational results showed that increasing the number of pressure points along the circumference can improve the measurement Accuracies of the FADS system. However, there is a threshold value. When the number of pressure points is the same, increasing the cone angle can significantly improve the measurement Accuracies of FADS. The asymmetric distribution of the orifices has no effect on the measurement Accuracies.