90°Y型汇流下小曲率矩形截面蛇形微通道气液两相流动特性
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摘要
以空气、去离子水为气液两相工质,采用直角Y型混合器,在矩形截面为800μm×100μm的蛇形微通道内利用高速摄像仪进行了可视化实验。通过改变气液两相流速,实验中发现了一些不同于直微通道的特殊流型。随着流动的进行,气戟、液塞的长度尽管在每一水平段变化比较微弱,但在整体上二者有增大的趋势。发现Qian等对当前气戟长度可以进行较好的预测。基于环状流,对Cioncolini等提出的空隙率预测模型进行了验证,发现该模型对蛇形结构也具有一定的意义。
Visualization studies were performed in serpentine microchannels with 90° Y-junction using a high speed camera. Air and deionized water were used as gas and liquid phase, respectively, and the channels were in rectangular shape with cross-section area of 800μm×100μm. Unusual flow patterns as often shown in straight microchannels were observed by changing gas and liquid flow rates. The results show that gas halberd or liquid slug length shows little change in each horizontal segment, but both increase gradually in the whole process. The predicted values from Qian's model agree with the present experimental results for gas halberd length, and the voidage model proposed by Cioncolini for results verification shows promising application in coiled structure prediction.
Visualization studies were performed in serpentine microchannels with 90° Y-junction using a high speed camera. Air and deionized water were used as gas and liquid phase, respectively, and the channels were in rectangular shape with cross-section area of 800μm×100μm. Unusual flow patterns as often shown in straight microchannels were observed by changing gas and liquid flow rates. The results show that gas halberd or liquid slug length shows little change in each horizontal segment, but both increase gradually in the whole process. The predicted values from Qian's model agree with the present experimental results for gas halberd length, and the voidage model proposed by Cioncolini for results verification shows promising application in coiled structure prediction.
引文
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[12]WANG Xiao-yan(王晓艳).Experimental research on heat transfer characteristics in horizontal serpentine tube(水平蛇形管内传热特性试验研究)[D].Zibo(淄博):Shandong University of Technology(山东理工大学),2011.
[13]MENG Meng(孟勐),PENG Xiao-feng(彭晓峰).The heat transfer heterogeneities of bends in flow boiling of hairpin tubes(蛇形管流动沸腾弯头处传热的非均匀性)[J].Journal of Engineering Thermophysics(工程热物理学报),2009,30(3):498-500.
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[17]Melkamu A.Woldesemayat,Afshin J.Comparison of void fraction correlations for different flow patterns in horizontal and upward inclined pipes[J].International Journal of Multiphase Flow,2007,33(4):347-370.
[18]Andrea Cioncolini,John R.Thome.Void fraction predicion in annular two-phase flow[J].International Journal of Multiphase Flow,2012,43:72-84.
[2]LIU Qian(刘谦),ZHANG Song-hong(张颂红),SHEN Shao-chuan(沈绍传),et al.Gas-liquid two-phase flow patterns and boundaries in a rectangular microchannel(矩形微通道内气液两相流型及其转换和实验研究)[J].Journal of Chemical Engineering of Chinese Universities(高校化学工程学报),2011,25(6):916-922.
[3]WANG Yuan(汪元),WANG Zhen-guo(王振国).Research on interfacial characteristics of ethanol evaporation in single microchannels using visualization and infrared thermography(基于可现代观测和结外测温技术的微通道中乙醇蒸发气液相界的特性研究)[J].Journal of Chemical Engineering of Chinese Universities(高校化学工程学报),2016,30(2):318-324.
[4]Fries D M,Waelchli S,Rohr P R.Gas-liquid two-phase flow in meandering microchannels[J].Chemical Engineering Journal,2008,135:S37-S45.
[5]ZHOU Yun-long(周云龙),SUN Zhen-guo(孙振国).Gas-liquid flow characteristics in serpentine microchannels(蛇形微通道气液两相流动特性)[J].CIESC Journal(化工学报),2015,66(11):4350-4358.
[6]Choi C W,Yu D I,Kim M H.Adiabatic two-phase flow in rectangular micro-channels with different aspect ratios:PartⅡ—bubble behaviors and pressure drop in single bubble[J].International Journal of Heat and Mass Transfer,2010,53(23):5242-5249.
[7]Yao Chaoqun,Zhao Yuchao,Ye Chunbo,et al.Characteristics of slug flow with inertial effects in a rectangular micro-channel[J].Chemical Engineering Science,2013,95(3):246-256.
[8]Qian D,Lawal A.Numerical study on gas and liquid slugs for Taylor flow in a T-junction microchannel[J].Chemical Engineering Science,2006,61(23):7609-7625.
[9]Sobieszuk P,Cygański P,Pohorecki R.Bubble lengths in the gas-liquid Taylor flow in microchannels[J].Chemical Engineering Research and Design,2010,88(3):263-269.
[10]Dang Minhui,Yue Jun,Chen Guangwen,et al.Formation characteristics of Taylor bubbles in a microchannel with a converging shape mixing junction[J].Chemical Engineering Journal,2013,223:99-109.
[11]Tsaoulidis D,Dore V,Angeli P,et al.Flow patterns and pressure drop of ionic liquid-water two-phase flows in microchannels[J].International Journal of Multiphase Flow,2013,54:1-10.
[12]WANG Xiao-yan(王晓艳).Experimental research on heat transfer characteristics in horizontal serpentine tube(水平蛇形管内传热特性试验研究)[D].Zibo(淄博):Shandong University of Technology(山东理工大学),2011.
[13]MENG Meng(孟勐),PENG Xiao-feng(彭晓峰).The heat transfer heterogeneities of bends in flow boiling of hairpin tubes(蛇形管流动沸腾弯头处传热的非均匀性)[J].Journal of Engineering Thermophysics(工程热物理学报),2009,30(3):498-500.
[14]Kositanont C,Putivisutisak S,Tagawa T,et al.Multiphase parallel flow stabilization in curved micro-channel[J].Chemical Engineering Journal,2014,253:332-340.
[15]Beattie D R H,Sugawara S.Steam–water void fraction for vertical up flow in a 73.9 mm pipe[J].International Journal of Multiphase Flow,1986,12(4):641-653.
[16]Hideo Ide,Tohru Fukano.Experimental research on the correlations of holdup and frictional pressure drop in air-water two-phase flow in a capillary rectangular channel[J].Experimental Thermal and Fluid Science,2005,29(7):833-841.
[17]Melkamu A.Woldesemayat,Afshin J.Comparison of void fraction correlations for different flow patterns in horizontal and upward inclined pipes[J].International Journal of Multiphase Flow,2007,33(4):347-370.
[18]Andrea Cioncolini,John R.Thome.Void fraction predicion in annular two-phase flow[J].International Journal of Multiphase Flow,2012,43:72-84.