Stability and uniformity of liquid film directly affect heat transfer of gas-liquid two-phase and gas-liquid-solid three-phase systems.Therefore,factors affecting the flow of liquid film were studied.Effects of slot width(2-5 mm),pipe diameter(73-113 mm),gas-liquid contact angle(0°-90°),friction coefficient(0.1-0.9),and gas velocity(2-10 m·s-1)on vertical falling film fluctuation characteristics at high Reynolds numbers were quantitatively analyzed from the perspective of liquid film thickness,liquid film velocity,and turbulence intensity.The results show that when the slot width is over 3.5 mm,the liquid film thickness remains unchanged,and the turbulence intensity changes relatively stable.The thickness,velocity,and turbulence intensity of the liquid film vary significantly with the increase of pipe diameter.As the gas-liquid contact angle increases,the thickness and velocity of the liquid film has little variation,while the turbulence intensity of the liquid film decreases slightly at the outlet.The thickness of the liquid film increases slightly with the increase of the friction coefficient.As the gas velocity increases,the thickness of the liquid film decreases sharply in the beginning and then slowly increases.Gas velocity has an inhibitory effect on liquid film velocity in the inlet region.
关键词
垂直降膜/液膜厚度/湍流强度/气液两相流/数值模拟
Key words
vertical falling film/thickness of liquid film/turbulence intensity/gas-liquid two-phase flow/numerical simulation
维普
万方数据