1.10. OpenFOAM and driftFluxFoam¶
These are notes on driftFluxFoam (Brennan 2001).
1.10.1. Two-fluids Model¶
1.10.1.1. Conservation of Mass¶
1.10.1.2. Conservation of Momentum¶
1.10.2. Mixture Model¶
Consider a mixture, not two phases: one continuity equation, one momentum equation and one convective diffuction equation for the dispersed phase
Increased efficiency: reduces number of equations from 4 to 3
Increased robustness: interphase momentum transfer term disappears (as momentum equations are added and the terms are equal and opposite)
Physically realistic: main slip between phases is gravitational settling, the settling velocity
New concepts: mixture density, centre of mass of mixture velocity, and diffusion velocities with respect to centre of mass of mixture velocity
1.10.2.1. Mixture Density¶
1.10.2.2. Centre of Mass of Mixture Velocity¶
1.10.2.3. Diffusion Velocities wrt Centre of Mass of Mixture Velocity¶
1.10.2.4. Mixture Conservation of Mass¶
The above concepts can be used to derive a new continuity equation for the mixture model: