Comparison of a Two Dimensional Adaptive Wall Technique With Analytical Wall Interference Correction Techniques

Comparisons of the chordwise pressure distributions at nearly the same normal-force coecient and Mach number are presented in a \Supplement to NASA TP-3132." Copies of this \Supplement to NASA TP-3132" will be furnished upon request. Requests for the supplement should be addressed to: Cut Date Please forward \Supplement to NASA TP-3132" to Name of organization Street number City and State Zip code Attention: Name Title 1 Summary Two wind tunnel investigations have been conducted to compare dierent correction techniques to account for wall interference: adaptive test section walls and classical analytical corrections. A common airfoil model has been tested in the adaptive-wall test section of the NASA Langley 0.3-Meter Transonic Cryogenic Tunnel (0.3-m TCT) and in the ventilated test section of the National Aeronautical Establishment (NAE) Two-Dimensional High Reynolds Number Facility (HRNF). The model has a 9-in. chord and a CAST 10-2/DOA 2 airfoil section. The 0.3-m TCT adaptive-wall test section has four solid walls with exible top and bottom walls. The ratio of the 0.3-m TCT test section height to the model chord is 1.4. The HRNF has porous top and bottom walls and solid sidewalls. The ratio of the HRNF test section height to the model chord is 6.7. The Mach number for the tests ranged from 0. The angle-of-attack range was from about 02 up to stall. Wall interference in the test results from the 0.3-m TCT has been accounted for by the movement of the adaptive walls, whereas the results from the HRNF have been corrected for top and bottom wall interference by classical analytical techniques. These results are in good agreement. The comparisons indicate that small residual errors remain in the Mach number and angle of attack. Correcting the results from both tests for the sidewall interference after correcting the results for top and bottom wall interference did not signicantly change the agreement. Correcting the results with a unied four-wall correction technique improved the agreement of the results with Navier-Stokes calculations.