Thermal Analysis of Heated Ducts in Battery Cooling Units using CFD

A battery cooling module is an auxiliary cooling system that provides cold air/coolant to the battery pack of a hybrid or electric vehicle in order to maintain low temperatures and improve battery life. For effective cooling of these batteries, it is important that the ducts that carry air/coolant are thermally efficient. This study analyzes the thermal behavior of these heated ducts by using Computational Fluid Dynamics (CFD). Primarily, a detailed study on type of flow namely, laminar and turbulent, boundary layer treatment (wall functions and wall y+), turbulence modeling (for a chosen turbulence model, k-omega-SST), rate of heat transfer near the wall, temperature coupling to solid walls, as well as grid dependence of the solution is performed. These numerical analyses are validated with analytical solutions in simple geometries like flow between two parallel plates. The results from the simulation finally represent a basis to numerically optimize the effective design of automotive cooling ducts in e-vehicles.