One-group interfacial area transport of bubbly flows in vertical round tubes

In relation to the development of the interfacial area transport equation, the sink and source terms in an adiabatic bubbly flow system were modeled based on the mechanisms of bubble–bubble and bubble–turbulent eddy random collisions, respectively. The interfacial area transport mechanism was discussed based on the derived model. One-dimensional interfacial area transport equation with the derived sink and source terms was evaluated by using the area averaged flow parameters of adiabatic air–water bubbly flows measured in 25.4 mm and 50.8 mm diameter tubes. The flow conditions of the data set covered most of the bubbly flow regime, including finely dispersed bubbly flow (inlet superficial gas velocity: 0.0414–3.90 m/s, superficial liquid velocity: 0.262–5.00 m/s, void fraction: 1.27–46.8%). Excellent agreement was obtained between modeled and measured interfacial area concentrations within the average relative deviation of 11.6%. It was recognized that the present model would be promising for the interfacial area transport of the examined bubbly flows.