| In multiphase operations, such as liquid-liquid or gas-liquid systems, the interfacial area affects the interfluid heat, mass and momentum transfer and ultimately, the overall equipment performance.; A 3D interfacial area concentration transport equation in cylindrical coordinates is formulated. Then a 2D-axisymmetrical interfacial area concentration (IAC) transport equation is formulated based on simplifying the 3D-IAC transport equation into 2D. A two-fluid model of turbulent, adiabatic bubbly flow, provided by the computational fluid dynamics (CFD) Fluent 6.0 program, is validated for the case of interest in this work. Turbulence in the dispersed (bubble) phase was neglected. Liquid turbulence was modeled through a two-phase extension of the single-phase standard k - epsilon model. The model was implemented in the Fluent 6.0 commercial CFD solver. A 2D-axisymmetric mesh is made using Gambit (Fluent geometry and meshing package) for two literature reported experiments. Fluent runs simulating these experiments were done using the Eulerian multiphase option and the k - epsilon turbulence option.; A Fluent based user defined scalar transport equation was adapted to compute values for IAC from the proposed new IAC transport equation. It was found that modification of the IAC transport equation source term was required to obtain satisfactory results. The modification made in this work consisted of partitioning the source term into two parts, one of them was retained, and the other was neglected based on a turbulent length scale argument. Calculations based on these results matched reported bubble column IAC data fairly well except at the axis of the column.; The model presented here is based on a modification of the source term in a 3D Interfacial Area Concentration model. This model is superior to one-dimensional models which developed by other researchers for two reasons: it has no adjustable parameters, and it is a 2D model whereas the other model simulations have been one dimensional to date. |
