Milli-channel with metal foams under an applied gas–liquid periodic flow: Flow patterns, residence time distribution and pulsing properties

Abstract

This work investigates the hydrodynamics of a square milli-channel filled with metallic open-cell-foams (OCFs) under an applied G–L Taylor flow. The hydrodynamic properties of the Taylor flow are not maintained but induce pulsations in the foam bed. Thus, flow patterns in the foam can be represented by liquid plug pulses alternating with meandering digital gas paths into quasi-stagnant liquid zones. The pulse study revealed that the flow behaviour is quite similar to that encountered in more classical granular media of lower porosity. Predictive correlations for pulse frequency and velocity are proposed. Liquid residence time distribution (RTD) experiments were performed and revealed that fluid velocities, liquid viscosity and foam geometrical properties control the system. High liquid hold ups up to 90% are estimated and a predictive correlation is proposed. Interestingly, the impacts of the foam and liquid properties on this liquid hold up appear less pronounced in contrast with literature on other granular media.