Tracking an aerodynamic model in a wind tunnel with a stereo high-speed imaging system

A method is presented to track the 3D motion of an aerodynamic model in wind tunnel tests with a stereo high-speed imaging system. The imaging system includes two high-speed cameras that work at 4,000 frames per second with a digital resolution of 1024×512 pixels. Stereo image recordings of tracking markers, which are precisely distributed on the model surface, are captured with a limited view angle difference between the two cameras. The stereo images are calibrated and 2D positions of tracking markers in the image frame are determined with a correlation-based algorithm. The camera positions and view angles are calibrated with a target shifting test. The determined 2D positions of both camera views in each stereo image recording are used to reconstruct instantaneous 3D coordinates of the tracking markers. A minimum quadratic difference approach is used to determine the center coordinates, roll angle, pitch angle and yaw angle of the aerodynamic model in the wind tunnel. Tests and simulations were conducted to verify the method.