Porsche Engineering Magazine

Issue 01/2004 Porsche Engineering Magazine Good Vibrations: Modern anechoic chambers with state-of-the-art measuring and testing equipment enable efficient analyses of individual components and complete vehicles. Lightweight Material for Vehicle Construction: With the Carrera GT, Porsche is the first manu- facturer to put magnesium components within view of the driver. Networked Systems: In addition to familiar net- working architectures, Porsche is using a new fiber optic based technology (MOST) in the Cayenne. Contents The Porsche Engineering Group Porsche is the only car manufactur- In conjunction with its domestic GmbH (PEG), a subsidiary of er to make its extensive engineer- and foreign subsidiaries, Porsche Dr. Ing. h.c. F. Porsche AG, is ing knowledge available to interna- Engineering provides expertise on a responsible for the sports car con- tional customers from various sec- global scale in the fields of automo- structor’s global contract develop- tors. tive engineering and transport under ment activities. the brand Porsche Engineering. Editorial Page 4 Complete Vehicle Testing Body & Safety Chassis Engine Drivetrain Magnesium: Light-Weight Material for Vehicle Construction Page 9 Good Vibrations Thanks to State-of-the-Art Measuring and Testing Equipment Page 5 Porsche Engineering has access to Would you like to know more about the resources of more than 3,000 Porsche Engineering? To request engineers from construction, proto- our new image brochure, simply type-built, production planning, pro- send an e-mail to: curement, logistics and production [email protected] divisions. Insights A Porsche Racer Without an Engine Page 19 The 911 Turbo Cabriolet – the Fastest Open Boxer on the Road Page 20 Umbrellas: Masters of the Wind Tunnel Page 21 Electrics & Electronics Industrial Engineering Styling Production Support Porsche Styling: Also Available for Two-Wheels Page 16 Special History of Airflow Tests at Porsche Page 22 Networked Systems in the Cayenne Page 12 Editorial Dear Readers In specific terms, our acoustic engi- With the Cayenne, Porsche entered neers are listening out for sounds new realms in communication and and vibrations from engines, com- data transfer between electronic ponents and even agricultural control modules. The MOST-based machinery that arrives for a sound (Media Oriented Systems Transport) check via Porsche Engineering at infotainment system guarantees the Weissach Development Centre. good vibrations from the loudspeak- ers during your journey. Good vibrations – for us at Porsche Engineering, this is what it is all about. Have fun reading the latest news. Your editorial team. The efficient analyses performed by the engineers in state-of-the art sound measurement chambers, equipped with the very latest in technology, form the basis for Porsche acoustic design. Porsche designers concentrate on appropriate and functional styling and do not limit themselves to four- wheeled objects. When it comes to two wheels also – coming back to the subject of good vibrations – the stylists again prove themselves to be exceptionally creative: the Porsche design studios in Weissach and Huntington Beach (Los Angeles) also provide an all-round service for motorbikes, from the initial drawing right up to completion of the entire model. 4 Acoustics Complete Vehicle Good Vibrations Thanks to State-of-the-Art Measuring and Testing Equipment On a single-axis roller test stand, measurements can be performed up to speeds of 300 kilometers per hour. At Porsche, studies into vehicle acoustics and vibrations have a tradition stretching back more than 30 years. State-of-the-art anechoic chambers offering the best in modern technology enable the efficient analysis of cars and their individual components. The acoustic technicians at indeed often for customers from Studies into acoustics and vibra- Porsche are responsible for every- completely different areas of indus- tions encompass a broad field. In thing that contributes to the unmis- try. Their work focuses primarily on the Sound Engineering section, takable sound of these sports cars, optimizing directly those compo- interior and exterior noises are and specifically for ensuring that nents that cause the interfering processed and optimized. The char- this sound is not impaired. They do noises or vibrations. Only then do acteristic sound of the brand, for not limit themselves exclusively to they resort to secondary measures example of the engine, is the very Porsche cars however: their many whereby the offending sources are lifeblood of Acoustic Design. years of experience are also put to attenuated or insulated. Rattles, creaks and squeaks, on the good use in customer projects, other hand, are the domain of the 5 Complete Vehicle Acoustics Next, the vehicle is prepared for the tests and the measurement equipment is hooked up. Specialist Porsche engineers from the most varied of backgrounds ensure that the specimen is optimally equipped, thus avoiding costly and time-inten- sive rework in the test chamber. Octagonal anechoic chamber for engines One particular highlight of the Porsche Acoustics department is The octagonal anechoic chamber for engines is clad with a new type of perforated sheet the modernized, octagonal engine wedge and largely fulfils accuracy class 1 for the frequency range for engine noises. anechoic chamber. This architectur- al structure approximates the Acoustic Quality section, where the Before a vehicle reaches one of the spherical shape that is so optimal technicians work to design the best acoustic test stands, however, it for acoustics and with which deep possible subjective sound impres- must first run a few circuits on the frequencies are also well absorbed. sion. With the help of noise source “status track”, so that the acoustic The chamber is lined with a new analyses, the causes of interfering technicians can quickly gain a first type of perforated sheet wedge and noises are tracked down and dealt impression of the situation and then largely fulfills accuracy class 1 in with in a concerted fashion. determine how they should proceed the frequency range relevant for and what test stands are required. engine noises (500 Hertz to 5 Kilo- In addition to acoustic optimization, the area of vibration comfort is of great importance. The engine and vehicle anechoic chambers at the Porsche Development Center in Weissach were modernized specifically to be able to conduct these multiple studies using the latest, state-of-the-art equipment in an appropriate environment. The acoustic camera records the sound field and generates a graphic of the noise distribu- tion. Thus sources of noise can be quickly located. 6 Acoustics Complete Vehicle hertz). Given that it is equipped as a full acoustic chamber, measurements can be taken from all sides, including from beneath the vehicle. The size of the chamber makes it possible to test complete aggre- gates (engine-gearbox differential), while the acoustic test stand caters for engines with a performance rat- ing of 400 Kilowatt, a maximum torque of 1,500 Newton-meters and a maximum speed of 8,000 rpm. As it also boasts all the functions of In the vehicle anechoic chamber, tests are conducted under almost free-field conditions. The acoustic camera (right) helps to locate sources of noise. a regular engine test stand, emis- sions and cylinder pressure measurements can also be taken in addi- Free-field conditions in the vehicle is so easily accessible when tion to the noise tests. vehicle anechoic chamber the vehicle is on the test stand, it is Porsche Engineering run acoustic particularly suitable for acoustic The acoustics test stand is equipped and vibration-related studies on and vibration-related tests on the with the PumaOpen automation sys- entire vehicles, motorcycles and chassis, powertrain or drivetrain. tem, which collects measurement individual chassis components data and monitors the test speci- under state-of-the-art conditions in The test rig is specifically set up to mens and test stand. It records all the large anechoic chamber. With enable numerous different tests on the system parameters of the its special design (room in a room) individual components, assemblies engine electronics during the test and the highly effective, sound- and sections of the car. Thus, com- and links these with the acoustic absorbing full lining (including the plex metrological analyses such as and vibration-related evaluations. floor), conditions approaching free- laser-vibrometric recording of a Thus, for example, newly occurring field are created. The chamber thus floor assembly, torsional vibration phenomena are immediately ana- corresponds to accuracy class 1. measurements on a drivetrain or lyzed. the localization of noise sources On the 220-Kilowatt single-axis using the acoustic camera can be Typical studies conducted in the roller test stand, high-speed meas- performed without difficulty. The engine anechoic chamber include urements (up to 300 kilometers per operational vibration of individual the analyses of sound and vibra- hour) can be performed on front structures, such as entire floor tions in the engines, drivetrains and wheel or rear wheel driven vehicles. assemblies or door-trim panels, are components in their different oper- Various lining plates or impact analyzed using permanently ating states. In addition, combus- strips are mounted as required on installed multi-channel metrological tion noises can also be studied. the bearing surface of the rollers, equipment. in order to simulate

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