Porous CFD Simulation

What is Porous Media?

Some materials have cavities and empty spaces in their structure, allowing fluid to move inside them, like a sponge. Such materials are called porous media. The types of porous structures can be categorized based on whether the holes are connected or not, and whether the structure of the holes is regular or irregular.

Aluminum foam is a type of porous medium that has an irregular structure. Adopted from “Computational fluid dynamics simulation on open cell aluminum foams for Li-ion battery cooling system” by Lip Huat Saw et al

Here are some important terms related to porous media:

• Porosity: It expresses the volume of empty space relative to the volume of material in porous media.
• Permeability: It is a measure of how easily a fluid can pass through porous media.
• Tortuosity: It expresses the complexity of the fluid path inside the porous media and shows how convoluted or winding the path is compared to the straight path.
• Capillary pressure: It refers to the pressure difference across the interface between two immiscible fluids in a porous medium due to surface tension.
• The Ergun equation: It estimates the pressure drop through a packed bed or porous medium based on the flow rate, fluid properties, and the bed’s characteristics.

Porous Media Applications

In some cases, porous media are used intentionally because of their advantages, while in other cases, porous media are naturally present in systems, such as some body tissues, making it necessary to study and understand them to modify the system effectively. Here are some key areas where porous media play a crucial role:

• Heat transfer: In some cases, porous media are used to improve heat transfer and increase the contact surface between the object and the fluid. This porous media is sometimes referred to as a heat exchanger. In some cases, porous media that do not allow fluid flow are used to make thermal insulation. In this context, CFD simulations are a good option to analyze and study the system.

CFD Heat Transfer 

• Civil and geotechnical engineering: Many structures in buildings, such as concrete, are porous. The structure of soil is also porous. Currently, ground settlement is an important issue caused by the emptying and collapse of the soil’s porous structure, leading to its compression. The study of porous media in this field, both experimentally and through simulation, has greatly helped researchers.
• Batteries and fuel cells: Electrodes in many electrochemical systems are porous media. The performance of a battery or fuel cell depends on how many ions are transferred into the porous media. Thanks to various experimental methods and complex CFD simulations, engineers have been able to make efficient electrodes.
• Environmental engineering: In many environmental applications, porous media are used. For example, many water purification devices use porous media to absorb solutes from water, and filters with porous structures are used to capture polluted particles from exhaust gases in factories.
• Biomedical engineering: In drug delivery, the desired substances must pass through body tissues, which requires understanding the porous structure of tissues and the fluid flow within them. Fat tissue accumulated in the veins is a type of porous media, as are many artificial tissues of the body, which have a complex manufacturing process. These artificial tissues must allow fluid and substances to pass through in the same way as natural tissues. Additionally, many body parts are porous media, which is essential to understanding treatment methods and drug delivery. All these factors highlight the importance of porous media in biomedical engineering, where experimental methods and CFD simulations are used to study them.

The lung is a porous medium, and the study of fluid motion is necessary to understand how pollutants such as cigarette smoke remain in it.

Simulation of Porous Media by ANSYS Fluent

There are many challenges for CFD simulation of porous structures. One of these is its porous and mesh structure. Simulations in this field can be done in both laminar and turbulent flow, depending on the conditions of the problem. In many cases, the fluid flow is multi-phase and contains particles; it may even be necessary to take into account the change in volume of the material due to temperature changes. In all these cases, ANSYS Fluent has proven its capabilities. So far, engineers have studied many phenomena in the field of porous media with this software, and by using simulation results, they have been able to optimize fluid flow through porous media in many systems.

Fluid flow velocity contour inside a porous structure. Adopted from “Ergun Equation Investigation for Porous CFD Simulation”

CFDLAND expertise in Porous Media Modeling Using ANSYS Fluent Software

We have many ready-made CFD porous media simulation projects in CFDLAND, which can be seen at the top of this page. You can also view all our ready-made projects in CFDSHOP. Take a look at them; perhaps one of them will suit your needs.

Trust our experts and order your CFD porous media simulation projects in order project. You will be impressed by the quality of our work.