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As more and more promising applications of magnetic nanoparticles in complicated environments are explored, their flow properties in porous media are of increasing interest. We here propose a hybrid approach based on the multiparticle collision dynamics method extended to porous media via friction forces and coupled with Brownian dynamics simulations of the rotational motion of magnetic nanoparticles' magnetic moment. We simulate flow in planar channels homogeneously filled with a porous medium and verify our implementation by reproducing the analytical velocity profile of the Darcy–Brinkman model in the non-magnetic case. In the presence of an externally applied magnetic field, the non-equilibrium magnetization and friction forces lead to field-dependent velocity profiles that result in effective, field-dependent permeabilities. We provide a theoretical expression for this magneto-permeability effect in analogy with the magneto-viscous effect. Finally, we study the flow through planar channels, where only the walls are covered with a porous medium. We find a smooth crossover from the Poiseuille profile in the center of the channel to Brinkman–Darcy flow in the porous layers. We propose a simple estimate of the thickness of the porous layer based on the flow rate and maximum flow velocity. [ABSTRACT FROM AUTHOR]

In the presented research article, the intelligence based numerical computation of artificial neural network backpropagated with Levenberg-Marquardt algorithm has been developed to analyze the novel ferrofluid flow model in the presence of magnetic dipole. Heat transfer effects are also incorporated along the horizontal. The designed fluid flow model initially represented by system of partial differential equations are converted into system of non-linear ordinary differential equations through suitable similarity transformations. The reference dataset of the possible outcomes is obtained from Adam numerical solver for the different scenarios of flow model by variation of co-efficient of the thermal expansion, Eckert number, suction parameter, magnetization and radiation parameter. The approximated solutions are interpreted for designed model by testing, training and validation process of backpropagated neural networks. Furthermore, the comparative studies and performance analysis of used algorithm is validated through regression analysis, histogram studies, correlation index and results of mean square error.

In the presented research article, the intelligence based numerical computation of artificial neural network backpropagated with Levenberg-Marquardt algorithm has been developed to analyze the novel ferrofluid flow model in the presence of magnetic dipole. Heat transfer effects are also incorporated along the horizontal. The designed fluid flow model initially represented by system of partial differential equations are converted into system of non-linear ordinary differential equations through suitable similarity transformations. The reference dataset of the possible outcomes is obtained from Adam numerical solver for the different scenarios of flow model by variation of co-efficient of the thermal expansion, Eckert number, suction parameter, magnetization and radiation parameter. The approximated solutions are interpreted for designed model by testing, training and validation process of backpropagated neural networks. Furthermore, the comparative studies and performance analysis of used algorithm is validated through regression analysis, histogram studies, correlation index and results of mean square error. [ABSTRACT FROM AUTHOR]

Ferrofluid is a kind of magnetic fluid, the flow of which is controlled by an external magnetic field. Owing to this property, ferrofluid, as a new function material, has raised extensive concern in the oil industry. In this paper, the issue of ferrofluid flow in complex porous media has been studied by numerical simulation, and the validity and accuracy of the numerical algorithm are demonstrated through a 1-D horizontal tube example. Later, the effects of the magnetic force on ferrofluid flow in complex porous media, such as heterogeneous and fractured porous media, are investigated. The results show that there is basically no flow in low permeability or secondary fracture without a magnetic field, due to the characteristics of porous media and displacement pressure distribution. However, the ferrofluid flow velocity and domain can be changed by applying an external magnetic field. This novel phenomenon may provide a new idea to enhance oil recovery based on controllable flooding technology or meet other industrial needs by using ferrofluid.

Water flooding is an efficient approach to maintain reservoir pressure and has been widely used to enhance oil recovery. However, preferential water pathways such as fractures can significantly decrease the sweep efficiency. Therefore, the utilization ratio of injected water is seriously affected. How to develop new flooding technology to further improve the oil recovery in this situation is a pressing problem. For the past few years, controllable ferrofluid has caused the extensive concern in oil industry as a new functional material. In the presence of a gradient in the magnetic field strength, a magnetic body force is produced on the ferrofluid so that the attractive magnetic forces allow the ferrofluid to be manipulated to flow in any desired direction through the control of the external magnetic field. In view of these properties, the potential application of using the ferrofluid as a new kind of displacing fluid for flooding in fractured porous media is been studied in this paper for the first time. Considering the physical process of the mobilization of ferrofluid through porous media by arrangement of strong external magnetic fields, the magnetic body force was introduced into the Darcy equation and deals with fractures based on the discrete-fracture model. The fully implicit finite volume method is used to solve mathematical model and the validity and accuracy of numerical simulation, which is demonstrated through an experiment with ferrofluid flowing in a single fractured oil-saturated sand in a 2-D horizontal cell.

• New way to avail the microstructure impact on non-equilibrium magnetization response. • Identification of a magnetic entrance length in ferrofluid channel flows. • Discussions on physical limits in which hydrodynamic-magnetic coupling is observed. • Identification of 3D effects in non-equilibrium regimes due to dipolar interactions. This work aims to reconstruct a continuous magnetization profile of a ferrofluid channel flow by using a discrete Langevin dynamics approach for the fluid's micro structure. The continuous magnetization field is obtained through the coupled solution of 2D Ferrohydrodynamics equations in a CFD approach using a numerical code developed by the authors. The discrete Langevin Dynamics simulations consider a collection of magnetically interacting particles subjected to long-range field-dipole and dipole-dipole magnetic interactions. The particles are also subjected to hydrodynamic drag and to Brownian fluctuations for the translational and rotational motion. It is assumed that the dipole moments of the magnetic particles are fixed to their mechanical body, meaning they rotate along the particle's angular velocity with no delay or advance. We identify an interesting demagnetization effect in the near wall region for moderate Brownian timescales associated with the competition between magnetic relaxation and flow's vorticity. [ABSTRACT FROM AUTHOR]