Stagnation line due to colliding wall jets of two liquid impinging jets on a horizontal surface

Abstract

When two free liquid jets impinge on a planar surface with their wall jets colliding, a stagnation line is formed between the two wall jets. The location and shape of the stagnation line depend on the free jet flow conditions, fluid properties, impingement orientation of each free jet, and relative positioning of the two free jets. Experiments are conducted to observe and measure stagnation lines formed by two free jets impinging on the upper surface of a transparent plate, and a camera is placed under the plate to take the images of stagnation lines. It is found that changing the fluid and the position and orientation of the two jets causes the stagnation line to change. A theoretical model consisting of momentum analysis of a singe wall jet and momentum balance of two wall jets is derived to predict the stagnation line. It is hypothesized that, when two unequal liquid wall jets collide, the stagnation takes place where the momentum balance between the two jets within the thinner thickness is satisfied. Based on the hypothesis, the developed theoretical model shows good agreement with the experimental results.