Some Problem for wall Interference Correction in wind Tunnel Testing

摘要

Wall interference problems in wind tunnel testing were discussed by many people. These are enough to correct the effect of wall interference for usual model testing, if there is a enough interval between the walls. But there are some problems. One of them is for limitation that we can use these methods. On this paper, I report some experimental data concerning with this problem. Experiments were done in the two dimensional wind tunnel. A testing model is circular cylinder which has 24mm for diameter and 200mm for longitudinal dimension. The walls of tunnel are movable between 60mm to 360mm for wall interval. All testing were done at the same Reynold's Number, i.e., U_0 d / ι = 4×104 The result shows as follow ; When H/d, a ratio between wall interval H and a diameter of circular cylinder, d, takes above 5.0, drag coefficient of the cylinder is constant, if the experimental data are corrected for the effect of wall interference. For the ratio below 5.0, drag coefficient increases gradually with decreasing the ratio, although correction is made for interference.