スリットノズルから噴射した空気の円筒容器内の流れに関する研究

抄録

The present paper describes the flow characteristics of air injected from a slit nozzle into a cylindrical container. The effect of the slit nozzle offset distance on the flow in the container were experimentally investigated. The velocity distributions were measured using the particle image velocimetry (PIV). The Reynolds number of the jet flow, Re = U₀b/ν (U₀: nozzle exit velocity (≈ 6 m/s), ν: air kinematic viscosity), was held constant (2000). The non-dimensional nozzle offset distance was changed from y_n/D = 0 to 0.4, where D is the diameter of the cylindrical container. When the nozzle is located at the center of the container i.e., y_n/D = 0, the jet oscillates with a large amplitude in the container and does not reach the bottom of the container as the same as the rectangular container. However, when the nozzle is offset close to the cylindrical container wall at y_n/D ≥ 0.2, the jet flows along the wall surface and reaches the bottom of container due to the Coanda effect. This non-dimensional nozzle offset distance is smaller than that of the compared rectangular container.