Christian Enderle

Variable Gestaltung des Abgasmündungsgeräusches am Beispiel eines V6-Motors

Zur wirksamen Unterstreichung der fahrzeugspezifischen Eigenschaften wie Qualitat, Leistung und Agilitat gewinnt die gezielte Gerauschgestaltung in immer hoherem Mas an Bedeutung. Wahrend fruher der gute Sound nur bei Motorradern und Sportfahrzeugen ein wichtiges Kriterium war, trifft dies heute fur eine Vielzahl von Fahrzeugtypen als Kaufargument zu. Um die Freiheitsgrade fur eine gezielte Gerauschbeeinflussung zu erlangen, wird in Zukunft die Bedeutung eines elektronischen Eingriffs weiter steigen. Dieser Beitrag von Daimler-Chrysler und Faurecia geht auf die Moglichkeiten des Einsatzes einer aktiven Einheit zur Gerauschgestaltung der Abgasmundung ein. Als Beispiel dient der V6-Ottomotor eines Roadsterfahrzeugs.

Specifics of Daimler's new SCR system (BLUETEC) in the Diesel Sprinter Van - Certified for NAFTA 2010

Beginning in 2010, Daimlers well known Diesel Sprinter van has to fulfill the new and clearly tighter NOx emission standards of NAFTA10 (EPA, CARB). This requires an integrated approach of further engine optimizations and the implementation of an innovative exhaust aftertreatment technology. The goal was to develop an overall concept which meets simultaneously the tightened emission standards (including OBD limits) and the increasing customer demands of more power and torque without loosing the high fuel efficiency of the small and highly efficient 3 liter V6 diesel engine OM642, which already has been installed in the NAFTA07 Sprinter. In the early stages of the concept phase, the most appropriate NOx aftertreatment technology and certification form (engine or vehicle) had to be selected for this specific vehicle class in the van segment with enhanced requirements to durability, economical efficiency and specific driving behavior. The implementation of Daimlers BLUETEC SCR system combined with a vehicle certification reveals the best way to meet the multilayer requirements. Due to the usage of a small passenger car derived but highly efficient diesel engine (OM642), the adoption of passenger car derived SCR components (AdBlue® dosing valve, tank and dosing system) was more appropriate as our heavy duty derived components. The following SAE paper illustrates the implementation of the SCR system (BLUETEC) into the Diesel Sprinter van in detail. Main investigation areas are the adaption and optimization of the exhaust gas system including catalyst coating and the AdBlue® dosing system, specifics of the operation strategy and the overall balancing of engine and exhaust system optimization to meet the van specific requirements and the customer demands for more power, torque and fuel efficiency. The result is an attractive and unique powertrain concept for vans in North America. The new NAFTA10 Diesel Sprinter offers now higher power (188hp) and torque (325 ft-lb) at even improved fuel efficiency (24.7 mpg) and significant lower NOx emissions (up to 90%) compared to its predecessor. Consequently, Daimler developed a clean, environmental-friendly and economical highly efficient sustainable solution for future transportation in the van segment of North America. Beginning in 2010, Daimler is going to sell the NAFTA10 Sprinter generation additionally as Mercedes-Benz vehicle in USA (all 50 states) and Canada, besides the well known branding as Freightliner.

New Mercedes-Benz four-cylinder gasoline engines with compressor

With the beginning of this year Mercedes-Benz began to replace the four-cylinder gasoline engine family M 111 with the completely new successor, internally designated M 271. The new engines had to gradually be adapted to the existing installation space in the C-Class of the third generation. Part 1 of this report in the last MTZ issue presented this new mechanically supercharged gasoline engine family with charge air cooling. This second part of the publication describes the basic aspects of this particular development path, which will allow greater fuel economy potential to be achieved, but requires more complex exhaust gas aftertreatment.

The exhaust system of the Mercedes SL 500

Even in its basic concept, the Mercedes SL 500 is more oriented towards sportiness and agility than its predecessor. With an appropriate sound and a low counterpressure, the exhaust system makes a not insignificant contribution to this. The sound engineering effort for the exhaust system is extensive, as strict legal and technical limits apply in this respect. The result is a compromise between a muscular/sporty and a more comfort-oriented sound, as the driver prefers. The exhaust sound is audible at all times, providing permanent feedback on the operating status, but without being obtrusive or irritating. Optimising the flow dynamics of the exhaust system by the extensive use of CAE assists the performance characteristics of the engine, directly benefiting driving enjoyment.

Die Abgasanlage des Mercedes SL 500

Der Mercedes SL 500 ist bereits in seiner Grundkonzeption starker als sein Vorganger auf Sportlichkeit und Agilitat ausgelegt. Die Abgasanlage liefert hierzu durch einen entsprechenden Sound und durch einen geringen Gegendruck einen nicht unerheblichen Beitrag. Der Aufwand fur das Sound-Engineering der Abgasanlage ist gros, weil hier enge gesetzliche und technische Grenzen einzuhalten sind. Das Ergebnis ist ein Kompromiss zwischen sportlich-kraftvollem und komfortbetontem Klang — je nach Wunsch des Fahrers. Das Mundungsgerausch der Abgasanlage ist stets prasent und gibt jederzeit Ruckmeldung uber den Fahrzustand, ohne dabei aufdringlich oder storend zu wirken. Die strΩungsmechanische Optimierung des Abgassystems durch umfangreichen CAE-Einsatz unterstutzt die Leistungsentfaltung des Motors, was dem Fahrspas zu Gute kommt.