Cover Story ACOusTiCs - Rieter

7 Engine compartment sound pressure level reduction due to engine-mounted encapsulation as a function of the area coverage
same time, they are thick enough to guarantee
acoustic and thermal insulation.
The local wall thickness and density
must be adjustable to comply with the
available space and, according to the characteristics
of the emitting noise sources,
must provide a balance between acoustic
absorption, insulation and heat insulation.
The area weight of the entire concept,
which integrates the acoustic and thermal
insulation functions, is less than 2.5 kg/m 2 .
Therefore, they allow the design of selfsupporting
parts that are able to cover
large surfaces.
ConCLusions
It is foreseeable that the internal combustion
engines of future vehicles will require
closed encapsulations in order to improve
fuel efficiency and reduce exterior noise.
This poses tremendous challenges for car
manufacturers in terms of added complexity,
weight, cost and thermal safety
problems.
The adoption of innovative system and
component architectures, as shown by the
Rie-BAY panel from Rieter, can achieve
almost complete encapsulation. The CO 2
reduction of 2.5 g/km is significant. What
is more, advanced internal combustion
engine concepts will be perceived by the
end customer as being quieter.
reFerenCes
[1] de Ciutiis, H.; Bürgin, T.; Gorlato, L.: Auswirkungen
von verschiedenen Motorraumkapsel-
Konzepten auf Emissionen, Verbrauch und auf die
thermische Betriebssicherheit im Motorraum eines
Pkws. in: Wärmemanagement des Kraftfahrzeugs.
Expert Verlag, Renningen, 2006
[2] Lehmann, D.: Engineering Process for an
innovative underfloor Module. Rieter Automotive
Conference, Zürich, 2003
[3] strategic Research Agenda of the European
Road Transport Research Advisory Council,
Dezember 2004
[4] Mantovani, M.; Lehmann, D.: Functional and
Material Acoustic Optimization integrated into
underbody systems for Vehicle Performance
improvement. sAE Paper 2007-01-2350
[5] Meschke, J.; Gaudino, C.; Bendell, E.: Design
and Optimization of an Engine-Mounted Thermal-
Acoustical Encapsulation. Rieter Automotive
Conference, Zürich 2007
[6] Viktorovitch, M.: Acoustics of a Modular
Engine Bay Encapsulation integrating a Porous Air
intake system. Rieter Automotive Conference,
Zürich 2007
special thanks go to Youhei Kumagai (mem-
ber of the infiniti Vehicle Engineering depart-
ment of the Advanced Vehicle Dynamic
Performance Development Group) and Dirk
Lehmann (formerly Global Product Manager
underbody and Engine Bay at Rieter Auto-
motive systems) for their valuable contribu-
tions to this article.
thanks
01i2010 Volume 112 17