This study describes immiscible fluid displacement near a transitional boundary at which inertial effect occurs. We simulated two-phase fluid flow in a 2D micromodel using the lattice Boltzmann method with varying Reynolds numbers (Re) (log Re = −2 to 2) and viscosity ratios (M) (log M = −2 to 0). To highlight the role of inertial force rather than capillary and viscous forces, the capillary number (Ca) was kept constant at log Ca = −5. As Re and M increased, development in the preferential flow became more pronounced with tortuous paths. We found the transitional boundary exists near log Re = −1 to 1 at which residual saturation of the displaced fluid starts to fluctuate and changes 5%–14% in the transitional regime. In particular, this boundary describes the effect of inertia on immiscible fluid displacement before an increase in the work done due to inertial force occurs.
All Science Journal Classification (ASJC) codes
- Water Science and Technology