Model Attitude Determination in Wind Tunnel with a Luminescent Paint Data System

Abstract

The question is addressed how registration targets in luminescent paint images can be used to determine model position and attitude (P&A) of the test article in a wind-tunnel test. The theory for such P&A determinations is developed and applied to data from a pressure-sensitive paint test in Arnold Engineering Development Center’ s 16-ft Transonic Wind Tunnel. It is shown that the camera system is capable of resolving pitch and yaw angles to within 0.005 deg rms. However, systematic differences as large as § 0.05 deg are found between the camera-based angles and angles determined from a sting-mounted balance. By analyzing the motion of the cameras relative to thetunnel walls, the observed discrepancies may beexplained by rotation of the cameras relativeto the test article. In some cases, these rotations are clearly correlated to operating conditions of the tunnel.