Engine encapsulation solutions and methods to support NVH and Thermal design optimization

Thermo-acoustic powertrain encapsulation systems either mounted on the vehicle body or directly onto the powertrain, have recently appeared on the market and are being investigated by many vehicle manufacturers. The reasons lie in the synergy provided by such systems between exterior and interior noise reduction and CO2 and fuel consumption reduction at cold start thanks to heat storage.
As high degree of coverage of the surface, and good packaging space is a key parameter for high heat storage and NVH optimization, these have to be engineered during vehicle design phase, clearly understanding how much the engineering choices taken will impact the performance of the end products. Until now, however, the acoustic and thermal performances tend to be considered separately, with different departments involved - typically NVH, thermal safety and energy management – with the leading function which depends on the focus of the project and considers the other functions as external requirements or niceto-have performances.
On the other hand, it is obvious that the potential for simultaneous thermo-acoustic optimization exists, to ensure the best performance-weight-cost balance of the encapsulation and to ensure thermal safety.
Autoneum is since ten years pioneering the research in this field and has developed dedicated thermoacoustic materials and specialized CAE tools for the computation of acoustic and thermal properties of components of the encapsulation systems.
In the course of the paper together with an overview on performance comparison between body mounted and engine mounted encapsulation solutions, it will be shown how these tools and materials can be used for simultaneous acoustic and thermal engineering, both for the purpose of the definition of component targets and for the performance monitoring along the evolution of the design of the encapsulation parts during the vehicle development process.