CAJ | 학술논문

利用高速摄像系统对梯形硅基微通道进行乙醇水混合蒸气冷凝流型可视化实验。梯形微通道结构为梯形，水力学直径165.87μm，通道长度50 mm。实验中混合蒸气乙醇质量分数范围为2%～60%。实验发现入口蒸气乙醇浓度对通道内流型有重要影响。沿着冷凝方向，发现环状流、环状条纹流、翻滚流、喷射流/喷射滴状流及气泡流。不同蒸气入口乙醇质量分数有不同的流型分布，低乙醇浓度的蒸气冷凝环状条纹流及喷射流区域出现伪滴状凝结形式，高乙醇浓度的蒸气冷凝出现翻滚流流型。实验以蒸气质量通量及蒸气干度为坐标对不同入口浓度蒸气冷凝建立了两相流型图，并对喷射流发生干度建立了流型转变预测式。
이용고속섭상계통대제형규기미통도진행을순수혼합증기냉응류형가시화실험。제형미통도결구위제형，수역학직경165.87μm，통도장도50 mm。실험중혼합증기을순질량분수범위위2%～60%。실험발현입구증기을순농도대통도내류형유중요영향。연착냉응방향，발현배상류、배상조문류、번곤류、분사류/분사적상류급기포류。불동증기입구을순질량분수유불동적류형분포，저을순농도적증기냉응배상조문류급분사류구역출현위적상응결형식，고을순농도적증기냉응출현번곤류류형。실험이증기질량통량급증기간도위좌표대불동입구농도증기냉응건립료량상류형도，병대분사류발생간도건립료류형전변예측식。
A visualization experiment was carried out to investigate the condensation flow patterns of the ethanol-water vapor mixtures in an array of microchannels under a wide range of concentration (2%—60%). The microchannel was a trapezoidal silicon one with a hydraulic diameter of 165.87μm and a length of 50 mm. The visualization study indicated that the ethanol concentration remarkably influenced the flow regimes. Along the flow direction, annular, annular-streak, annular-streak-droplet, annular-churn, injection, droplet-injection and bubble flow patterns were observed in the vapor mixtures condensation of different inlet ethanol concentration (60%, 31%, 20%, 6%, 4%, 2%). Due to the Marangoni effect, the film of the annular flow was more fluctuant comparing with the pure steam condensation. With the decreasing of the ethanol concentration, the injection flow pattern became more regular and the droplet would appear in the injection flow area. The two-phase flow pattern maps of different inlet ethanol concentrations were also developed to describe the experiment. A correlation based on the critical quality correlation was proposed to indicate the transition of the two-phase flow patterns.