Study of the Flow Around a High Voltage Battery Module to Be Applied in Leak Testing

The air tightness of the High Voltage (HV) battery housing in the automobile industry protects the battery from adverse elements in the environment such as pressure, temperature changes and the appearance of moisture in the housing. A quality control process occurs on the production line and is a mandatory step for every battery produced. An optimized process will save time and costs. The process will use the Massflow method in order to measure the leakrate. It consists of using air under pressure to analyse the leakrate of the studied volume. Non-negligible impacting factors of this method are the different modules placed in the battery itself. The modules impact the process because of their geometry and their own leakage as they have an internal volume. To improve the method, an efficient way to study the process is to use a numerical model. The numerical model was of a single module that was tested numerically and experimentally in order to validate the numerical method. In addition it was used to identify some first improvements in the quality of the testing. To create the numerical model, the Smoothed Particles Hydrodynamics (SPH) method was used. This method uses a Lagrangian point of view to tackle the simulation, meaning the fluid is discretized into several particles that interact together. In order to validate the use of this model, it was compared with an experiment. To observe the flow around a module and validate the model, a setup was created in which the battery module was put in a box where the pressure can be controlled and monitored. A digital twin of this setup was created that allows the visualization and the study of the flow around the module when a pressure change occurs at an inlet of the box. The goal of these studies is to examine the stabilization of the flow around the module: how the geometry of the module, the geometry of the testing box or the air supply can affect a fast stabilization in the properties of the flow. The research focuses on improving the airflow in the testing box. To do this, the spot where the pressure stabilizes the latest is determined and then solutions identified to improve its stabilisation. Numerous solutions were investigated like the change of geometry but also the placement or number of the exchange cables. In the future, this research will study the flow surrounding the module and identify the specific areas that will have to be investigated in a full battery housing setup. As a consequence, this will improve the quality control process in the production of HV batteries.      «

The air tightness of the High Voltage (HV) battery housing in the automobile industry protects the battery from adverse elements in the environment such as pressure, temperature changes and the appearance of moisture in the housing. A quality control process occurs on the production line and is a mandatory step for every battery produced. An optimized process will save time and costs. The process will use the Massflow method in order to measure the leakrate. It consists of using air under pressu...     »