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Generally within engineering design, the current emphasis is on biasing the development process towards increased virtual prototyping and reduced “real” prototyping. Therefore there is a requirement for more CAE based automated optimisation, Design of Experiments and Design for Six Sigma. The main requirements for these processes are that the model being analysed is parametric and that the solution time is short. Prediction of gear whine behaviour in automatic transmissions is a particularly complex problem where the conventional FEA approach precludes the rapid assessment of “what if?” scenarios due to the slow model building and solution times. This paper will present an alternative approach, which is a fully parametric functionality-based model, including the effects of and interactions between all components in the transmission. In particular the time-varying load sharing and misalignment in the planetary gears will be analysed in detail.

The spark ignition engine is a prime source of vibration energy. NVH disturbances generated by the engine ultimately reach the customer in the form of objectionable noise or NVH. Exhaust Manifolds are one of the many sources of noise contributors among the engine components. Often, the exhaust manifold is identified as a source of objectionable NVH late in the design and development process. Due to the lack of an upfront NVH analysis tool, a new CAE NVH methodology for evaluating new exhaust manifold designs has been investigated and developed by the Ford Motor Company's V-Engine CAE and Exhaust Manifold Design Sections. This new CAE methodology has been developed to compare the NVH performance of current production exhaust manifolds to new design levels. Mechanical induced radiated shell noise is the predominate cause of objectionable NVH in exhaust manifolds.

In this paper, a CAE methodology based on a multiphysics approach for engine gear noise evaluation is reviewed. The method comprises the results and outputs from several different analytical domains to perform the noise risk assessment. The assessment includes the source-path analysis of the gear-induced rattling and whining noise. The vibration data from the exterior surface of the engine is extended through acoustic analysis to perform the engine noise simulation and to identify acoustic hot spots contributing to the noise. The study includes simulations under different engine loading conditions with results presented in both time and frequency domains. Various sensitivity analyses involving different gear geometries and micro-geometries are investigated as well. Finally, the simulation results from three different engines are compared vis-a-vis.