CAE Methodology for Optimizing NVH, Functional Reliability, and Mass Reduction at Engine Concept Design Phase

摘要

Due to the global economic downturn and higher environmental awareness, the social demands for low cost and fuel efficient vehicles are increasing. At the same time the engine power is increasing and customer expectations of reliability and NVH levels are increasing. To meet all the requirements, engineers are challenged to design light weight parts with higher performance. However, unconsidered mass reduction carries a risk of compromised NVH, Functional Reliability, and other functional demands. In order to resolve this contradiction, it is important to establish a basic structure with minimum necessary mass at the concept design phase, when there are still many degrees of freedom in the design space. Hence, a multi-objective optimization CAE methodology applicable for designing the basic structure of the Engine system was developed and is detailed below. This paper is divided into the following two sections: 1) NVH optimization process by improving multi-flexible-body dynamic calculation efficiency. 2) Methodology for optimizing NVH, Functional Reliability, and mass reduction for Engine. By applying this method to an inline four cylinder engine, the targets for NVH and Functional Reliability around the bore were achieved while the Engine system mass was reduced compared to the current production engine.