Two-phase flow behavior in a mini channel is studied by both experimental and numerical methods. Various surface conditions are considered to capture the fundamental characteristics of water droplet behavior in a PEMFC gas channel. In the considered rectangular channel with 1 mm height, critical velocity for annular flow type is measured as 1∼2 m/s of superficial air velocity. Two-phase flow pattern shows some uncertainty near transition zone with aluminum surface. With carbon paper GDL, two-phase flow pattern is stabilized. Measured two-phase pressure drop data explains the relation between two-phase flow pattern and two-phase pressure drop. Numerical simulation using VOF technique successfully mimicked the development of water droplet and corner flow as well as formation of a slug. It also explains the possibility of random slug formation with aluminum surface and stabilized two-phase flow pattern with carbon paper GDLs.
Genuine Two-Phase Flow Dynamics with a Free Interface Separating Gas-Liquid Mixture from Gas
