空气－水在壳侧垂直向上、向下横掠水平管束的两相流动特性

TWO-PHASE FIOW CHARACTERISTICS IN VERTICAL UP-AND-DOWN FLOW A HORIZONTAL TUBE BUNDLE

对空气－水混合物在壳侧垂直向上、向下横掠水平管束流动时的平均截面含气率及两相摩擦压降进行了实验研究。管束为正方形顺排，管间距离与管径之比１．２８．试验表明，质量流率对平均截面含气率及两相摩擦压降有显著的影响；截面含气率的测量值明显低于均相模型的预测值。提出了壳侧垂直向上、向下横掠水平管束时预测截面含气率及两相压降的新的关联式。

Void fraction and friction pressuredrop measurements are madefor an adiabatic,verticalup-and-down two-phase flow of air-water mixture across a horizontal.in-line,5×20 rod bundle withpaith-to-diameter ratio,P/D,of 1.28.The average void fraction and friction pressure drop show astrong mass velocity effect,the val ues of void fraction are significantly less than those predicted by ahomogeneous flow model.New correlations for predicting void fraction and twophase pressure drop invertical up-and-down flow across a horizontal tube bundle are presented.The data are compared tothose published in the literatures。