Numerical simulation of gas–liquid two-phase flow in a horizontal manifold with downward branches

Abstract

Large eddy simulations (LESs) with the volume of fluid (VOF) method are applied to gas–liquid two-phase flows in a horizontal manifold with five downward branches under various inlet flow rates and quality conditions, and the validity is examined by comparison with an experiment. Furthermore, the correlation for the prediction of the liquid mass fraction, defined as the ratio of the liquid mass flow rate at each branch and the inlet liquid mass flow rate, is investigated based on the LES results. The results show that the predicted liquid mass fraction is the highest at the first downward branch and gradually decreases at the downward branches located downstream, which is consistent with the experiment, both qualitatively and quantitatively. Based on the LES results of the various inlet flow rates and quality conditions, a new correlation expression on liquid distribution rate (LDR), defined as the ratio of the inlet liquid flow rate and outlet liquid flow rate of the branch, is proposed. It is possible for the proposed correlation expression to significantly reduce the air-conditioning system evaluation cost.

Keywords

• two-phase flow
• numerical simulation
• maldistribution
• branches
• air-conditioner