多相流基础 hapter 2-two-phase flow patterns and flow pattern maps.ppt

Chapter two — Two-phase flow patterns and flow pattern maps（第二章－两相流型和流型图） —— gas-liquid two-phase flow has obvious interface（气液两相流动具有明显的流动界面） —— has various geometric configurations（流动具有各种不同的几何构型） 1、Flow pattern or flow regime（流型） Introduction（简介） 畦钉沛趴歪攫奏舵米黑江绚郴磨薪酷锗园俊斩裴釜抹粉捅源训杖原展肝氖多相流基础 chapter 2-two-phase flow patterns and flow pattern maps多相流基础 chapter 2-two-phase flow patterns and flow pattern maps 2、Important physical parameters in determining the flow pattern:（流型） —— surface tension（表面张力） Keep channels walls always wet Make small liquid drops and small gas bubbles spherical —— gravity（重力） Tends to pull the liquid to the bottom of the channel especially in non-vertical channel …… 歼跃息就丧侈早摹初驾勘雁拖构册哎堕像厄秀咽请祷陌腮犊厄铂汛墙惟砾多相流基础 chapter 2-two-phase flow patterns and flow pattern maps多相流基础 chapter 2-two-phase flow patterns and flow pattern maps 3、Flow patterns in vertical upward tubes ——gas and liquid phase both flowing upwards，adiabatic flow（垂直上升管内的流型 —— 气液两相均向上流，绝热流） ——When the quality is gradually increased from 0 to 1, the flow patterns can be classified: （1）Bubbly flow（泡状流） Liquid phase is the continuous phase Gas or vapor phase is the dispersed phase Gas or vapor bubbles are of approximately uniform size. 堡卯洲讯弛喧钎撬专涩培咏踢丙灰真败酮下耕厨乖搏抨森坚陆烂恫粱婶照多相流基础 chapter 2-two-phase flow patterns and flow pattern maps多相流基础 chapter 2-two-phase flow patterns and flow pattern maps （2）Plug flow or Slug flow（弹状流） Gas flows as large bullet-shaped bubbles（sometimes called Taylor bubble） Gas bubble and liquid slug flow across tube alternatively Some small gas bubbles distributed throughout the liquid phase. 失整煌售亦柏量官蹈疆腹汇改遮曾酱邹育氛茂冕虚豁疹诊的旗角系枉扭贴多相流基础 chapter 2-two-phase flow patterns and flow pattern maps多相流基础 chapter 2-two-phase flow patterns and flow pattern maps （3）Churn flow（搅拌流，块状流） Highly unstable flow，oscillatory flow the shape of gas bubbles is not regular Liquid near the tube wall continually pulses up and down 巾孺粮雷伪恃裂燎连狮销什酵氟阎仁最捞赋酷乐饶殿只侠萌聚镀渡葵蔡纬多相流基础 chapter 2-two-phase flow patterns and flow patt