Wind-Tunnel Boundary Corrections for a Full-Scale 1903 Wright Flyer Replica

A panel code is developed in order to assess and correct wind-tunnel boundary interferences during a test of a full-scale reproduction of the 1903 Wright "Flyer" in the Langley Full-Scale Tunnel (LFST). The LFST is a very large, low-speed wind tunnel with a 3/4-open test section. The principal concerns relating to boundary corrections are the relatively large size of the replica relative to the test-section dimensions, coupled with the lack of modern correction techniques for aeronautical testing in open-jet test sections. The Flyer is represented either by simple lifting surfaces, with the accuracy of the representation validated by direct calculations using the panel code CMARC, or by an array of simple horseshoe vortex singularities. Vortex ring panels are used in the boundary correction code. The solution starts by solving the flow in a closed test section in order to obtain the flow properties on the boundaries. An iterative method, based on the one-step method employed in adaptive wall wind-tunnel work, is then used to adapt the boundary geometry to a constant-pressure condition. Finally the boundary interference is obtained by calculating the velocities induced in the test region by the boundary singularities. Results are presented for different test-section boundary configurations: fully closed, fully open, and 3/4 open. Corrections are compared to calculations using the classical method of images.