Battery Cooling System Airborne Noise Correlation Using Statistical Based

<div>In a traditional electric vehicle, managing its battery thermal performance is of prime importance. A well-designed battery thermal management system helps in extending its life and avoids safety-related issues like thermal runaways. A critical part of this thermal management is the battery cooling system (BCS), which can be air- or liquid-cooled. Based on the vehicle battery pack size, location, and its design complexity, the original equipment manufacturer can opt for either of the previous two methods. An air-cooled type of BCS system usually involves an active ventilation fan to dissipate the battery heat in the surroundings, which brings symbiotic noise into the picture.</div> <div>In an air-cooled BCS system, the primary source of noise is the cooling airflow over the heat exchanger caused by the fan. The airflow and noise performance characteristics of this fan are typically measured by the supplier in a standalone condition. These performance parameters deviate greatly when the fan is introduced inside a battery cooling module.</div> <div>In the current work, flow-induced noise simulation of a fan placed inside a confined BCS is performed. The simulation has made use of a statistically based tool due to its inherent low dissipative and dispersion properties. The simulation model included all complex interior parts of the BCS, including the mating gaps higher than 1 mm. The simulation results were correlated with the test, and further iterations were performed in simulations to understand the sensitivity of the condenser core location with respect to the fan. Additionally, the changes in noise performance behavior while moving from a standalone fan toward a fan integrated with the BCS system are also studied. The overall noise correlation between the simulation and test is achieved within a 0.4 dBA level. Further, the presence of flow-induced resonance inside the BCS at a lower frequency than the BPF was identified in simulation.</div>