Heat Sink Cooling with a Porous Medium

Heat Sink Cooling with a Porous Medium, ANSYS Fluent CFD Tutorial

Description

This project simulates fluid flow inside a porous medium used for heat sink cooling with ANSYS Fluent. The study of fluid flow in porous media is one of the most widely applied fields in science and engineering: a porous medium consists of a perforated material containing pores and void spaces, which greatly increases the surface area available for heat exchange. In this case, a porous aluminum foam in contact with a heat source acts as the heat sink — the coolant flows through the foam's internal structure and absorbs heat far more effectively than flow over a plain solid surface.

The model is designed in three dimensions using Design Modeler. The geometry consists of a hollow inlet section followed by the porous aluminum foam, which is in direct contact with the heat source. The mesh is generated in ANSYS Meshing as a structured grid with a total of 7,680 cells.

Methodology

The fluid flow and heat transfer inside the porous medium are simulated in ANSYS Fluent. The coolant enters through the inlet boundary with a velocity of 1.99 m/s at a temperature of 300 K, passes through the porous zone, and absorbs the heat transferred into the foam from the attached heat source.

The energy equation is enabled to solve the heat transfer between the porous medium and the fluid, and turbulence is modeled using the RNG k-epsilon model with the standard wall function.

Analysis

At the end of the solution process, the temperature, velocity, and pressure fields are obtained, along with streamlines and velocity vectors. The temperature results show how the fluid heats up as it passes through the porous zone, carrying thermal energy away from the heat source.

The pressure contour reveals a key characteristic of porous media flow: the pressure behind the porous medium differs significantly from that at the outlet boundary, due to the flow resistance the porous zone imposes on the system. This pressure drop is the trade-off for the enhanced heat transfer — an essential design consideration when using porous inserts in cooling applications. By completing this project, you will learn to define a porous zone in ANSYS Fluent, set up conjugate heat transfer with a heat source, and evaluate the balance between cooling performance and pressure loss.