Preliminary Layout Design Method of Flush Airdata Sensing System

The flush airdata sensing system (FADS) is a measurement method that calculates aircraft airdata by obtaining the pressure distribution from the ports. The traditional design method of port layout is to install the ports on the side of aircraft nose, where the pressure is sensitive to angle of sideslip and angle of attack. Yet, for the aircraft whose surface pressure gradient with respect to angle of sideslip is rather slighter than that with respect to angle of attack, especially for blended wing body configuration, its measurement errors of angle of sideslip will increase significantly. In order to enhance the measurement accuracy, this article proposes a resolution-based port layout design method for plane aircraft, while the traditional gradient-based design method deteriorates. First, the pressure distribution of aircraft under various cases is obtained by the computational fluid dynamics method, and then, the feasible set of ports is introduced. Second, the layouts under different port counts are gained by the resolution-based method and the traditional method. Finally, it establishes the FADS to predict the angle of attack, angle of sideslip, and airspeed by an artificial neural network and evaluates the performance of the resolution-based method and the traditional method. The result shows that the resolution-based method obtains the optimal layout and has a quite minor error and system uncertainty than the traditional method, which effectively improves the system's accuracy.