由于考虑了气泡的破裂和聚合,同两流体模型相比,MUSIG模型(多尺寸组模型)能更准确地描述流场内气泡直径.采用MUSIG模型详细分析了不同壁面热流量,液体入口速度,过冷度以及不同管道高度时通道内气泡相界面面积、当地气泡直径、空泡系数等参数沿径向的分布.分析结果表明,MUSIG模型可用来预测泡弹状流型转变区的流动参数,也即该模型拓展了两流体模型的使用范围.%Considering the mechanisms of bubble coalescence and breakage, MUSIG (Multiple-Size-Group) model can supply a more accurate description of the diameter of bubble in the boiling flow of liquid nitrogen comparing with two fluid model. The MUSIG model is applied here to analyze flow boiling of liquid nitrogen in a vertical annular channel, local radial distribution of the mean interfacial area concentration, Sauter diameter and void fraction with different liquid inlet velocity, heat flux , liquid inlet subcooling and height of tube in vertical annular pipe. The numerical results illustrates that the MUSIG model can be used to predict flow parameters in the two phase flow structures from bubbly to slug or churn turbulent boiling flows., which also mean the use of two fluid flow is extended by the MUSIG model.
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