Gas-liquid bubbly flow in vertical pipes (Data Bank contribution)

Gas-liquid bubbly flow was investigated in vertical pipes for different flow conditions: fully developed turbulent downward flow in a 42.3 mm diameter pipe and upward flow in a 14.8 mm diameter pipe with liquid of elevated viscosity. Wall shear stress, local void fraction, and liquid velocity profiles, shear stress, and velocity fluctuations were measured using an electrodiffusional method. Results obtained demonstrate the existence of ''universal'' near-wall velocity distribution in a downward bubbly flow. The reduction of turbulent fluctuations is observed in downward flow as compared to a single-phase turbulent flow. The development of bubble-induced liquid velocity fluctuations in a ''laminar'' bubbly flow was studied.