正方形ダクト内への傾斜噴流による昇圧効果と速度分布に関する実験的研究

抄録

Experimental study is carried out to clarify the flowfield of the duct flow with an inclined jet injection, as the model test of a tunnel ventilation facility. A 7700 mm long duct with a 230 mm×230 mm square cross section is constructed, and an injection nozzle with 20 mm×230 mm outlet with the angle of 30° is installed at 2100 mm from the inlet. In addition to full span injection cases, the nozzle with 40% span (symmetric) or 50% span (one side) is installed to observe the effect of the outlet span on three dimensionality of the flowfield. Measured pressure gains under various flow ratios showed good agreement with the theory based on the law of momentum. The velocity distribution with full span injection showed the flowfield in which high speed regions are confined at the ceiling due to Coanda effect, while the partial injection cases revealed stronger down wash.