Multiscale Battery Thermal Modeling: Macro and Micro-scale Battery Thermal Model Improvements
Typ
Examensarbete för masterexamen
Program
Applied mechanics (MPAME), MSc
Publicerad
2022
Författare
Basavapatna Shesh, Amith
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
This thesis work concentrates on improving the existing battery thermal model used
by Volvo cars. Improvements are brought about in two specific aspects of the battery thermal model; motivation behind choosing these two aspects was to better
match the simulation results to the previously conducted test results. The first
aspect concentrates on explicitly modeling total heat transfer i.e. conduction, convection and radiation through small air gaps inside the battery module (order of a
few mm). Computational Fluid Dynamics (CFD) simulations were carried out using
Star-CCM+. Result showed that at a small expense in computational time, a large
improvement in accuracy could be attained.
The second part of the thesis concentrates on studying heat transfer across micro
asperities. It is of common practice to assume that two seemingly flat surfaces in
contact with each other to have perfect conductive heat transfer at the interface.
In reality, there are micro asperities as a result of surface roughness, these micro
asperities give rise to a thermal resistance at the interface between the two surfaces.
Results from this study prove that under certain conditions and for certain material
interfaces within the battery module, it would be an oversimplification to make the
initial observation about perfect conduction between the two surfaces. A methodology to predict contact resistance in the battery module is successfully established.
Further, a sensitivity study was carried out to better understand which material
pair(s) inside the battery module contributes the most in terms of thermal contact
resistance (Rc).
Beskrivning
Ämne/nyckelord
contact , resistance , heat-transfer , CFD , thermodynamics , battery