The effects of Reynolds number, coflow stream and surface roughness on a steady two-dimensional wall jet were examined experimentally in an atmospheric boundary layer wind tunnel using a Cobra probe. Five Reynolds numbers in the range 56,500 < Re < 134,000 and five values of coflow velocity/jet velocity ratio ranging from 0.11 to 0.23 were considered. In addition, a 40-grit sheet was used as the rough surface to investigate the effect of surface roughness. The results demonstrate that the Reynolds stress increases with the decrease of slot Reynolds number, and the effects of a higher Reynolds number on the spread of the half-height and the decay of maximum velocity are less pronounced. The coflow and surface roughness have a clear effects on the streamwise development of the half-height and the maximum mean velocity. The coflow significantly decreases the spread rate and the decay of maximum velocity compared with those without coflow, while the surface roughness increases those parameters relative to those on a smooth surface.

使用 Cobra 探头在大气边界层风洞中通过实验检查了雷诺数、协流流和表面粗糙度对稳定二维壁射流的影响。56,500 < Re范围内的五个雷诺数  < 134,000 和共流速度/射流速度比范围从 0.11 到 0.23 的五个值被考虑。此外，使用 40 目砂纸作为粗糙表面来研究表面粗糙度的影响。结果表明，雷诺应力随着槽雷诺数的减小而增大，且较高的雷诺数对半高扩展和最大速度衰减的影响不太明显。协流和表面粗糙度对流向发展的半高和最大平均速度有明显的影响。与没有协流的参数相比，协流显着降低了铺展率和最大速度的衰减，而表面粗糙度相对于光滑表面上的参数增加了这些参数。