風洞の特性に及ぼす整流金網, 縮流ノズルの影響

抄録

Effects of screens and two-dimensional contractions on a small open wind tunnel have been studied experimentally. Different mesh size of screens, number of screens, contraction ratios, nozzle length and nozzle shapes are investigated. Hot-wire anemometer is used for measuring the velocity profile and the turbulence intensity at the exit of the wind tunnel. It is found that the turbulence intensity decreases with the increase in the contraction ratio and number of screens. The turbulence intensity depends slightly on the mesh size of the screens. The short length nozzle makes the uniformity of the turbulence in the horizontal direction worse. The nozzle with the cosine curve can be regarded as better than the Batchelor-Shaw nozzle contour for the two-dimensional contraction.