Magnetic fluid is a new type of smart material, which
holds implications
for highly enhancing the oil displacement efficiency. In the present
study, we perform a comprehensive investigation to probe the influence
of a magnetic fluid on the displacement efficiency in porous media
under the action of magnetic force. First, the displacement efficiency
is measured by a self-developed setup, where factors such as the magnet
thicknesses, the volume of the fluid injected, the fluid injection
speed, and the porosity of the sample are surveyed as controllable
variables. Moreover, the experimental results are well verified by
the scaling laws according to the principle of dimensional balance.
Next, a numerical simulation is performed to explore the detailed
displacement process. First, the magnetic force generated by the ring
magnet is calculated. Then, the function curves of the displacement
efficiency with respect to the controlling variables are validated
by the numerical simulation. In addition, the numerical simulation
also demonstrates the volume phase distribution, the pressure field,
and the velocity field of the mixed fluid during the displacement
process. The simulation results are in excellent agreement with the
experimental data. These findings are beneficial for us to better
understand the oil displacement with the aid of external fields, which
also provide inspiration for the areas of microfluidics, diffusion
of pollutants, microsensors, etc.