Nano-Fluid: Heat Transfer in a Porous Heat Exchanger

Nano Fluid Heat Transfer in a Porous Heat Exchanger, ANSYS Fluent CFD Simulation Tutorial

Description

This project simulates the heat transfer of a nanofluid flowing through a porous-medium heat exchanger using ANSYS Fluent.

The core of this case is the nanofluid itself. A nanofluid is a base fluid, such as water, carrying suspended nanoparticles. Those particles raise the fluid's effective thermal conductivity, so a nanofluid can move more heat than the base fluid alone — which is why nanofluids are attractive in heat-exchanger and cooling applications. Rather than resolving individual particles, the nanofluid is treated as a single fluid with modified thermophysical properties, and this porous heat exchanger is a practical setting to demonstrate the heat-transfer benefit it provides.

The exchanger uses a porous medium as its heat-transfer core. Porous media contain many small pores and passages that greatly increase the internal surface area available for heat exchange, which is why they appear across industry — in crude-oil production, building insulation, and heat-recovery exchangers, among others. Here the nanofluid flows through this porous section and exchanges heat with it.

The geometry was built in ANSYS Design Modeler and meshed in ANSYS Meshing, using a structured grid for the upstream and downstream sections and an unstructured grid for the middle (porous) region, for a total of 1,901,882 cells.

Simulation Methodology

The incoming working fluid is a nanofluid, defined through its effective properties, and the energy equation is enabled to resolve the temperature field. The flow enters at 1.63 m/s; the porous core is held at 343 K and the tube wall at 293 K, setting up the temperature difference that drives the heat transfer.

Results & Conclusion

After solving, contours of pressure, velocity, and temperature were obtained, along with streamlines and velocity vectors. The temperature contours clearly show the heat exchange taking place, particularly within the porous region, and the velocity vectors follow the pores and passages of the porous medium as the nanofluid works its way through it.