Search Results

This paper reflects an efficient and comprehensive approach for vehicle sound optimization integrated into the entire development process. It shows the benefits of early consideration of typical vehicle NVH features and of intensive interaction of P/T and vehicle responsibilities. The process presented here considers the typical restriction that acoustically representative prototypes of engines and vehicles are not available simultaneously at the early development phase. For process optimization at this stage, a method for vehicle interior noise estimation is developed, which bases on measurements from the P/T test bench only, while the vehicle transfer behavior for airborne and structure-borne noise is assumed to be similar to a favorable existing vehicle. This method enables to start with the pre- optimization of the pure P/T and its components by focusing on such approaches which are mainly relevant for the vehicle interior noise.

The intake manifold of a gasoline engine has a significant influence on the operational behavior of the engine. With respect to the dominating influence parameters on the full load behavior which are the runner length and cross section, the requirement of a variable intake manifold geometry becomes stronger than ever before. For the part load behavior, the intake charge motion is gaining more significance as well, which leads to new requirements for variable elements in the intake manifold. Besides these directly influencing layout parameters on the gas exchange and combustion process, secondary aspects such as the satisfaction of the acoustical requirements, the weight reduction and the integration of other components and functions into the complex intake manifold module will be discussed. The intake manifold of passenger car gasoline engines has undergone a significant development progress during the last two decades.

For the reason of environmental and health protection, future Diesel emission legislation will become increasingly severe. Ceramic honeycomb traps are well suited to efficiently reduce particulate emissions. Several of such filtering devices have been introduced, but the major problem of regenerating the trap regarding reliability and failsafe operation is not yet sufficiently solved. This paper describes a particulate trap system with a self supporting, sequential regeneration system. The regeneration of the collected soot inside the channels of the honeycomb trap during vehicle opertion is initiated by ignition of the soot layer using meander shaped heat wires installed in the front end of the trap inlet channels.

The market share of Diesel engine passenger cars has increased during the last years in Europe and will become a factor of significance also in Asia and in the USA in the near future. This is mainly due to the outstanding good fuel economy of Diesel engines compared to gasoline engines. Namely the recent development and the introduction of the DI-Diesel technology also for passenger car size engines provided a major contribution in the reduction of the passenger car fuel consumption. State of the art passenger car Diesel engines have overcome the drawbacks of the Diesel engine in terms of poor driveability, low specific power output and annoying noise behaviour compared the gasoline engines since turbocharging and intercooling are available for mass production passenger car engines and very efficiently combustion process and structure optimizations have been carried out. Further development efforts have been undertaken to comply with the stringent emission regulations of the future.