Optimizing base engine design in view of performance, emission requirement, durability, and lighter weight has been a challenging work in automotive industry for a last couple of decades. While those functional requirements are designed and developed to be met, NVH requirement has been one of difficult objectives to be optimized in the design and development process, not only because of technical difficulties, but of the lesser degree of settlement of development process in a vehicle program.
The combustion characteristic of an engine plays an important role in the performance, emission, and NVH development. In this paper, the engine radiation sound and mounting vibration have been measured simultaneously with the combustion pressure from each cylinder of a V8 engine while varying the engine speed under wide open throttle condition and spark timing.
The results from the sensitivity study was part of engine development process and used for setting a reasonable condition to optimize the NVH requirement and other engine functional goals. In addition, it is recommended that the sensitivity analysis on combustion system design or tunings should be a standard process to optimize early development of engine NVH design.