Recent experience in improving the accuracy of wall interference corrections in TsAGI T-128 wind tunnel

Typical sources of systematic errors in the wind tunnel tests are considere d and analyzed with emphasis on the prediction of wall interference problem s. The review is made on the methods of wall interference corrections and b oundary condition measurements in connection with the T-128 test technique development. The levels of interference corrections for transport aircraft tests are estimated using the computer codes based on linear subsonic theor y and predicted boundary conditions. The main results of the transport airc raft test are presented and analyzed. The improved corrections based on the locally measured relationships between disturbed velocity components near upper and lower walls are applied to the experimental results. This techniq ue enables to achieve precise and reliable interference-free experimental d ata. The scatter of corrected data in the whole range of perforation ratios (from 0% to 18%) is the following: +/-0.02 degrees for lift coefficient/angle of attack dependence, +/-2 drag counts for drag coefficient. (C) 2001 Elsevier Science Ltd. All r ights reserved.