EHD Effect on Nanofluid: Charge Density

Electric Field Effect on Nanofluid Heat Transfer (EHD) — ANSYS Fluent CFD Simulation

Description

This project uses ANSYS Fluent to investigate the effect of an electric field on nanofluid heat transfer in an N-shaped cooling pipe, applying the EHD (Electrohydrodynamic) module coupled with the DPM (Discrete Phase Model). A potential difference is established between the pipe shell (positive) and a central wire (negative), driving charged aluminum nanoparticles through the coolant to enhance heat transfer from the hot pipe walls. Cool water enters the pipe and absorbs heat from walls held at 390 K, with the outlet temperature rise used to evaluate the effect of the particles and electric field on cooling performance. Within the Magnetohydrodynamics & Electrohydrodynamics (MHD & EHD): All Levels CFD Training Package, this project opens the Electrohydrodynamics block, introducing the electric field effect as the EHD counterpart to the magnetic-field nanofluid cases.

Methodology

The 3D geometry is built in SpaceClaim, with an inlet, outlet, hot wall zone, an inner wall representing the central wire, and an outer wall representing the pipe shell. The domain is meshed in ANSYS Meshing using an unstructured grid of 2,966,928 elements and 720,300 nodes. The EHD model is combined with DPM to simulate the current generated between the positive and negative poles and its effect on heat transfer from the walls. Aluminum nanoparticles are modeled as inert solid particles with a diameter of 0.00001 m, a charge density of 23, and a total flow rate of 1e-20 kg/s, using the DPM model with interaction with the continuous phase. The energy equation is enabled to resolve the temperature distribution, and the results are compared between a case with particles and electric field versus a baseline case without them.

Analysis

Temperature contours show more uniform heat distribution in the case with particles and electric field, with the average domain temperature rising by 0.1 K (310.43 K vs. 310.31 K) and the average outlet temperature rising by 0.5 K (316.59 K vs. 316.16 K) compared to the baseline. Velocity contours also show a more uniform flow field in the particle-laden case, indicating that the electric field's influence on the charged nanoparticles measurably improves cooling performance and heat distribution uniformity. By the end of this project, you'll be able to couple the EHD module with the Discrete Phase Model, drive charged nanoparticles through a coolant with an applied electric field, run a comparative study against a baseline without the field, and interpret the temperature and velocity fields that reveal how electrohydrodynamic effects enhance nanofluid heat transfer.