Flush Air Data System (FADS) Validation in a Subsonic Wind Tunnel

Abstract

Flush air data sensing system (FADS) makes use of surface pressure measurements from the nose cap of the vehicle for deriving the air data parameters of the vehicle such as angle of attack, angle of sideslip, Mach number, etc. The overall FADS system including pressure transducers, tubing, port geometry, FADS algorithm, and electronics along with the mechanical and electrical integration scheme is successfully tested in a subsonic wind tunnel facility. The tests are carried out in a low speed wind tunnel at wind speed of 65 m/s (Mach=0.2). For each blow-down, angle of sideslip (beta) is set at one value and angle of attack (alpha) is varied. Air data measurements (alpha, beta, Mach number) in each blow-down is analyzed and compared with the set conditions. For first developmental flights, the demanded accuracies from FADS are of the order of +/–2° in alpha and beta. Details of the FADS system, the embedded algorithm and the various interfaces are explained. The tests conducted and the performance obtained by comparing with the set conditions is presented in this paper. The experimental result establishes that the accuracies demanded are provided by the system.

Keywords: FADS, subsonic, angle of attack, wind tunnel

Cite this Article

Vidya SB, Jayakumar M, Finitha KC et al. Flush Air Data System (FADS) Validation in a Subsonic Wind Tunnel. Journal of Aerospace Engineering and Technology. 2016; 6(3): 5–15p.