Numerical Simulation on Pressure Drops for Air-Water Two-Phase Flow in Micro-Channels

Rigorous two-phase flow modeling is one of the great challenges in the thermal sciences. A two-dimensional computational fluid dynamics (CFD) simulation of air-water two-phase pressure drop characteristics in micro-channels by using volume of fluid (VOF) method was carried out in this paper. The simulations were performed in a horizontal micro-channel with a diameter of 1.1 mm and a length of 200 mm. Firstly, a variety of air-water two-phase flow patterns (including bubbly, slug, slug-annular and annular flow) were simulated in order to validate the feasibility and reliability of the VOF method. Next to that, the two-phase pressure drops in micro-channel were analyzed numerically by using the same CFD method. Also the comparison of pressure drop among the numerical simulations, experimental data and the results calculated by homogeneous equilibrium model was presented. The agreement between numerical results and the existing experimental data was found to be satisfactory. Based on this good agreement, it is finally found that the numerical analysis procedure proposed in this paper can be used to achieve a better prediction for micro-channel air-water flow characteristics.