This paper was produced for the 2019 NAFEMS World Congress in Quebec Canada
Vehicle Thermal Management (VTM) is one of the key activities during vehicle integration and validation process. It directly affects vehicle performance and safety and enables reliability and durability of automobile components. This is particularly critical for hybrid/electric vehicles considering the performance and safety of high-voltage battery pack, inverters and other heat-sensitive electronic components. Computational Fluid Dynamics (CFD) has traditionally proven to give reasonably accurate predictions of vehicle thermal characteristics under a set of steady-state thermal inputs, representing the vehicle operating under a specific constant working condition (speed, RPM, etc). In contrast, when it comes to modeling of time-dependent cases, the lack of temperature prediction during highly transient events posts risk of component failure due to unexpected thermal impact. However, running full transient thermal CFD in a traditional fashion often yields to prohibitive computational resource. Lack of temperature predictive capability during highly transient events posts risk of component failure due to unexpected thermal impact. The VTM CAE community shares the strong desire of performing transient thermal analysis for higher-fidelity simulation. This work showcases a recent investigation of a new simulation process to overcome high computational cost of transient VTM analysis. This is done by leveraging new functionality offered by the CFD solver and creative engineering judgements and assumptions. As a result, the proposed new process has revealed ability of capturing critical transient thermal responses for components of interest. The analysis turn-around time is very reasonable using computational resources typically available to VTM CAE analysts today. In this work, details of the proposed simulation process will be discussed. An example of the transient thermal behaviour of the vehicle going through highway cruise, hill climbing, and thermal soaking will be showcased.
|Date||18th June 2019|