Emerging Technology for Transonic Wind-Tunnel-Wall Interference Assessment and Corrections

Wind-Tunnel-Wall Interference Assessment and Correction (MAC) concepts, applications, and typical results are discussed in terms of several nonlinear transonic codes and one panel method code developed for and being implemented at the NASA Langley Research Center. Contrasts between 2-D and 3-D transonic testing factors which affect WIAC procedures are illustrated using airfoil data from the NASA Langley 0.3-Meter Transonic Cryogenic Tunnel (TCT) and Pathfinder I data from the NASA Langley National Transonic Facility (NTF). In addition, very recently obtained 3-D transonic WIAC results for Mach number and angle-of-attack corrections to data from a relatively large 20° swept semispan wing in the solid-wall NASA Ames High-Reynolds Number (HRN) Channel I (1.92% solid blockage) are independently verified by 3-D thin-layer Navier-Stokes free-air solutions. Initial results from the 3-D WIAC codes are encouraging; research on and implementation of WIAC concepts will continue.