Vehicle thermal management (VTM) simulations are becoming increasingly important
in the development phase of a vehicle. These simulations help in predicting the
thermal profiles of critical components over a drive cycle. They are usually
done using two methodologies: (1) Solving every aspect of the heat transfer,
i.e., convection, radiation, and conduction, in a single solver (Conjugate Heat
Transfer) or (2) Simulating convection using a fluid solver and computing the
other two mechanisms using a separate thermal solver (Co-simulation). The first
method is usually computationally intensive, while the second one isn’t. This is
because Co-simulation reduces the load of simulating all heat transfer
mechanisms in a single code. This is one of the reasons why the Co-simulation
method is widely used in the automotive industry. Traditionally, the methods
developed for Co-simulation processes are load case specific. A new methodology
for the Co-simulation process is proposed in this study, which can be used
across multiple load cases. This is done by adopting a modular approach to the
process by splitting it into three modules: (1) Fan, (2) Heat Exchanger, and (3)
Exhaust System. For the Fan Module, a new approach has been developed that
enables (a) faster simulation times and (b) simulation of dynamic fan speeds.
Using the proposed model for the Heat Exchanger, its behavior during Thermal
Soak can be accurately simulated. A one-dimensional/three-dimensional (1D/3D)
hybrid model has been proposed for the Exhaust Module that combines the
advantages of 1D and 3D simulation schemes. A broad spectrum of experiments was
chosen to validate the modularity of the methodology. The tests were uphill
drive at 60 km/h, Maximum Vehicle Velocity, Thermal Soak, and Stop and Go. The
simulations showed encouraging results in comparison to the experiments. This
enables the creation of a common methodology for simulating a virtual testing
scheme [1].