長方形ツインジェットの流れ特性に関する研究

～ノズル間隔の影響～

抄録

The effect of the nozzle spacing on the flow characteristics of twin rectangular jets was studied experimentally. The rectangular nozzle has a height of 10 mm and a width of 20 mm. The nozzle spacing between the center of twin rectangular jets was varied from S = 44 mm to 110 mm. Measurements of mean and fluctuating velocities were made with cross-wire probes for Reynolds number = 1.5 × 10⁴ based on the equivalent diameter d_e of 16 mm. In case of S/d_e = 2.75, the merging and combined points of the twin jets become closer to the nozzle exit than that of the other spacing ratio S/d_e because of the increment of mixing between the twin jets. In case of S/d_e = 6.875, the spread of mean velocity and turbulence increase at x/d_e ≥ 30 than that of the other spacing ratio S/d_e. Also, at x/S > 4.36, the mean velocity u /u_max and turbulence u^'rms/u_max has similarity for the dimensionless parameters of y/S.