Alfred Rust

Complete NVH Optimisation of a Passenger vehicle with a D. I. Diesel Engine to Meet Subjective Market Demands and Future Legislative Requirements

For optimisation of total vehicle noise-vibration-harshness (NVH) the interaction of the power unit and other noise sources with the power unit mounting system, the vehicle chassis structural response and the vehicle local transmission losses have to be taken into account. In this paper the procedure adopted for optimising the NVH of a production off-road vehicle equipped with a DI-TCI diesel engine is reported. The short time scale available for the engine and vehicle project demanded the adoption of a refined strategy which allowed, in parallel, both a low overall noise level and a high quality noise character to be achieved by feasible and cost effective methods. This combined approach adapted for balancing and controlling engine noise, other vehicle noise sources and vehicle response with respect to exterior and interior noise and subjective noise character, is discussed.

Reduction of noise from engine components by using high damping materials

Effective means of further improving the acoustic properties of internal combustion engines is the use of high damping materials such as cellular aluminium. Studies of acoustic material properties have been made at the Acoustic Competence Centre Graz (ACC) in cooperation with AVL List GmbH. A new method of power flow analysis was developed and both the usability and the acoustic potential have been verified by means of prototypes of an oil sump.

Geräuschreduktion von Motorbauteilen durch hoch dämpfende Werkstoffe

Eine wirksame Moglichkeit, die akustischen Eigenschaften von Verbrennungsmotoren weiter zu verbessern, ist der Einsatz neuer, hoher dampfender Werkstoffe, zum Beispiel von zellularem Aluminium. Dazu wurden entsprechende Werkstoffe am Akustikkompetenzzentrum Graz (ACC) in Auftrag und Zusammenarbeit mit der AVL List GmbH untersucht. Zudem wurde eine neue Bewertungsmethode der Leistungsflussanalyse entwickelt sowie die Einsatzfahigkeit und das Potenzial von Aluminiumschaumen anhand von Prototypen einer Olwanne bewiesen.

Active path tracking

Powertrain — induced structure — borne noise, up to approximately 800 Hz, will often be a major factor influencing vehicle interior noise and its quality. This may be a positive influence — often, however, powertrain structure borne noise will introduce unwanted harshness or roughness resulting from a ‘poor mix’ of engine crank speed harmonics (multiples of firing frequency). In this article, AVL List GmbH, Austria, describes a new tool for the quick and reliable analysis of such engine harmonics.