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The increased adoption of downsized engines along with higher electrical demand is generating a challenge to the Front-End Accessory Drive (FEAD) system functioning and validation. One alternative to speed up the validation of potential design solutions is the in-vehicle experimental tests approach. Nevertheless, experimental data collection during in-vehicle FEAD evaluation imposes some challenges due to, for instance, packaging space constraints and sample rate required to capture the dynamic events during vehicle operation, among others. In order to overcome this limitation, the objective of this research is focused in the development of a customized test rig that emulates FEAD layout of an actual automobile in a simulated operating condition.

Increasingly research has been conducted lately towards reduction of both fuel consumption and gases emission in automotive vehicles propelled by Internal Combustion Engines. Among many initiatives, downsizing of those engines has been broadly adopted, arising side effects as increased vibration levels along Front-End Accessory Drive (FEAD) system. The present study focuses on the potential improvement of transmission efficiency and of vibration levels along FEAD by considering different layouts for the system. Multiple combinations of alternator pulley technologies and tensioner types are evaluated either during in-vehicle tests or in customized test rig that emulates vehicle FEAD in operating conditions. Specific transducers spred over the vehicle and at test rig assure the relevant data are captured for every layout arrangement investigated.

Vehicle consumers are becoming more and more insightful and watchful, design alone is not anymore the main factor of differentiation. Generally, they evaluate and compare different models searching for the best cost benefit package, wherein acoustical comfort is an important requirement in the decision. The OEM’s, on the other hand, unceasingly search to identify these requirements so that they`re taken into account in the process of conception of new models. They consider countless information, ranging from the perception of the consumers and information from satisfaction research up to comparative analysis data between competing models (benchmarking), thus defining what’s called targets of the project. In order to realize benchmarking analysis in the NVH field, dozens of operational and laboratory tests are realized, generating hundreds of gigabytes of objective or quantitative data and subjective or qualitative data.

Currently, the simulation models in acoustics and vibrations are built considering only the main structures of the vehicle, as its basic structure (Body-in-white, BIW), doors, dashboard, and so on. To take into account the contribution of components with less influence (such as carpets, seats, sound insulation, and so on) in the behavior of the overall response of the model, the average characteristics of these materials are inserted evenly distributed in these models. However, to obtain models with better correlation levels is necessary to consider local characteristics of the application of these components. In this work was developed and numerically validated, the model that describes the standardized test of “Oberst Beam” (ASTM E 756-98) to obtain the damping of the blankets used for damping of the panel vibration. With these characteristics, in future work, is expected to be possible, also with a good correlation, consider the effect of these materials on whole vehicle.

Currently the numerical simulations of the vibro-acoustic behavior of vehicles are built considering only major structures, such as its basic structure (body in white), doors, dashboard etc. To take into account the contribution of other components (such as trims, seats, sound insulation etc.) to the overall response of the model, the average characteristics of these materials are inserted globally in this model. However, for more correlated models is necessary to consider local characteristics of these components. This work presents the numerical procedure for simulating the effect of the structural damping of viscoelastic coatings and the acoustic absorption of the trims such that its effects can be considered in the model of the full vehicle. The operating forces applied to the model were estimated from the laboratory and road tests using the SPC/TPA technique.

This work presents a numerical model to simulate oil flow in power steering pumps. A detailed three-dimensional geometry was used, considering rotor, inlets and outlets. Moving mesh capability was used because of the variations of the domain geometry with the pump rotation. Two operating conditions were simulated: 3000 rpm and 8000 rpm. The results investigated low pressure regions which could give place to cavitation problems and recirculation zones, as well as geometric details used to improve performance and reduce of pressure fluctuations and noise levels.