Search Results

The next generation of automotive engines has to meet 2004 emission limits, ideally with improved fuel economy and with noise emission which is at least 3 dBA below the current status. Using both simulation and experimental analysis these challenging requirements can only be fulfilled by clearly defining all key steps in NVH development and by applying suitable technological methods. The development procedure discussed in this paper is characterised by several aspects: two stage prediction procedure fully integrated in the design process, combustion development with a definite focus on noise, a closed loop between simulation and test bed development and consideration of noise in the calibration of engine and drivetrain management systems. Apart from meeting target noise levels, noise quality is the reference parameter which is continuously evaluated by means of the AVL Annoyance Index.

This paper will highlight the criteria and development efforts which have to be considered when planning to launch a SUV (Sports Utility Vehicle) or LDT (Light Duty Truck) equipped with a diesel engine. Basic engine design aspects as well as the choice and calibration of diesel fuel injection equipment will be discussed. Since the vibration excitation of the diesel engine is significantly higher than that of a comparable gasoline engine, the engine mounting arrangement is extremely important to guarantee good vibration isolation. Gear ratios have to be matched to the different torque and speed characteristics of the diesel engine. Finally, refinement of the complete vehicle with regard to interior and exterior noise is required.