Battery Cooling: Thermal Management by PCM

Battery Cooling (Thermal Management) by PCM, ANSYS Fluent Training

Description

This project simulates the cooling of a lithium battery through phase change material (PCM) application, using ANSYS Fluent. The simulation proceeds in two stages: first modeling a single lithium battery on its own, then adding two PCM layers on either side of the battery body — allowing a direct comparison of the PCM's effectiveness in the battery cooling process.

The 3D geometry was designed in SolidWorks and imported into Design Modeler, built across two configurations. The initial battery model measures 11.3 mm thick, 335 mm long, and 167 mm wide; the second configuration adds two 12 mm thick PCM layers to both sides of the battery. The domain was meshed in ANSYS Meshing using a structured grid, totaling 93,090 elements for the first case and 276,660 for the second. Given the nature of this problem, a transient solver was used throughout.

Methodology

As the battery operates, the electric current flowing through it generates heat, raising its internal temperature. This behavior was captured using a volumetric heat source defined within the battery region, calculated as R·I² — where R is the battery's internal resistance (10 mΩ in this simulation) and I is the current intensity (86 A) — yielding a heat generation rate of approximately 120,000 W/m³.

The Solidification and Melting model was used to represent the PCM's phase-change behavior, defined with a solidus temperature of 307 K, a liquidus temperature of 309 K, and a latent heat of fusion of 240,000 J/kg. The laminar model and energy equation were enabled to solve the governing flow equations and capture the resulting temperature distribution.

Conclusion

Results include 2D and 3D temperature contours for both simulation stages, directly compared at the end of the simulation, along with a plot tracking the battery's average temperature over a full hour for both the with-PCM and without-PCM cases.

The results confirm that applying a PCM coating to the battery body meaningfully cools the battery and slows its rate of temperature rise compared to the uncoated case. Additional 2D and 3D contours of the PCM's liquid volume fraction, obtained specifically for the second simulation stage, further illustrate how the PCM's progressive phase change directly governs its heat transfer interaction with the battery body — confirming the PCM layer's role as an effective passive thermal management solution for battery cooling applications.