Application of a wall pressure method in a wind tunnel test section with adjustable longitudinal slots

Green´s theorem has been applied to the problem of wind tunnel wall interference. A wall pressure method for test sections of rectangular cross sections has been completed, which can be used for the computation of wall interferences, wall adaptation and, in case of adaptive test sections, for residual wall interferences. For these cases, a single computational step is sufficient. Measurements in the transonic wind tunnel TWG of DLF Gottingen with adjustable longitudinal slots on the top and bottom walls show that for this special application the determination of residual wall interference is also reliable. Test data, e.g., force coefficients, can be corrected to be approximately interference-free, using the residual interference velocities. After correction, the discrepancies between test data from different slot widths were substantially reduced