Gas-liquid-solid (catalysts) reactive systems encountered in trickle bed reactors are common in chemical engineering related cocurrent gas and liquid downflow systems. Among these processes relying on trickle beds, hydrodynamics of foaming systems are less prominently explored subject despite the formation of foaming is very often in the petroleum industries. This studys aim was to demonstrate experimentally the effects of liquid and gas flow velocities, and liquid surface tension for key phenomenon like regime transition change, two-phase pressure drop, dynamic liquid hold-up and liquid...