In this chapter a general model for the two-phase fluid flow in porous media is presented, together with its simplified form, known as the Richards equation, which is applicable (under specific assumptions) to describe water flow in the vadose zone. In each case the governing equations are formulated at the Darcy scale, using the capillary pressure–saturation relationship and an empirical exten...

A physically-based method to derive well-posed instances of the two-fluid transport equations for two-phase flow, from Hamilton principle, is presented. The state flow represented by superficial velocity and drift-flux, instead average velocities each fluid. This generates conservation two principal motion modes naturally: global center-of-mass relative between fluids. Well-posed can be obtaine...

Intricate fluid flow and transport phenomena in porous media are ubiquitous natural processes engineering systems [...]

In the present study, the main objective is to evolve a correlation to predict liquid-liquid two-phase heat transfer coefficients in a spiral plate heat exchanger. Experimental studies were conducted in a spiral plate heat exchanger using the liquid-liquid two-phase system of water-diesel in different volume fractions and flow rates as the cold fluid. Experiments were conducted by varying the v...