In the present experimental study, the flow behavior at the Y-shaped gas-liquid mixing region of a rectangular channel was examined. Liquid injection angle and gas-liquid flowrates were chosen as experimental parameters, and the gas-liquid interfacial shape at the mixing region, wave pattern at the downstream and the gas pressure drop across the mixing point were investigated. Air and water were used as the test fluids. The rectangular test channel was 8mm high, 40mm wide and 500mm long. The flow ranges of air and water were 0∼278 liter/min. 0∼1 liter/min, respectively. The interfacial shape at the mixing region was represented by the penetration depth. It was identified from a set of photographs that the liquid penetration depth is increased by increasing of the liquid flowrate, and by decreasing of the gas flowrate. Larger penetration depth occurs with the larger liquid injection angle. Blockage effect, defined by the additional pressure drop across the mixing point due to the discharge of the liquid jet from the bottom, was examined. The blockage coefficient, which is a measure of the blockage effect, appears to be larger with the larger liquid injection angle. Also, the gas flow rate for the inception of the interfacial waves becomes smaller with the larger liquid injection angle.
