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.
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.
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.
