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Several factors influence a company working culture including its industry, its geographical region, as well as the cultural and the educational background of its employees. Despite these, Japanese companies have successfully transferred a company’s working culture from Japan to other countries [2], so that only minor regional differences in productivity remain. Such transfer is possible with a strong process oriented mind set and working style. This paper examines the change in a working culture associated with the prototyping of exhaust systems in India. That change required a shift from a reactive “firefighting” mode of working to a structured, projectable and reliable working environment. The goal was to achieve increased in-time delivery, higher quality, greater flexibility, more innovation and reduced cost. The same process approach may be transferred from India to other parts of the world, while allowing for country-specific influences on a company’s working culture.

The Rybnik Eng Center was reactivated at the beginning of 2008. One of the objectives of this new center is to develop the lean spirit and to directly apply it to the new center. Two years have now passed and these 2 papers give the opportunity to review the current status and to reflect on the lessons learned so far on our lean journey. The 2 papers are structured around people, processes and tools. The first paper focuses on the people, the second one on the processes and the tools. Some great progress has been made in the different areas of application including: - Processes: Some key engineering processes in Testing, CAD, CAE and prototype shop were thoroughly investigated and improved. Especially the quality of the outputs and significant reductions in lead times have been achieved. - Tools and Technologies: Tenneco worked on both aspects, the soft and hard tools. Soft tools are covering visual management which allows a better alignment.

The Rybnik Engineering Center was reinforced at the beginning of 2008. One aim of this new center has been to develop the lean spirit and to directly apply it to the new center. Two years have now passed and these 2 papers give the opportunity to review the current status and to reflect on the lessons learned so far on our lean journey. The 2 papers are structured around people, processes and tools. The first paper focuses on people which arguably represents the most challenging aspect of the development of an R& D center abroad. One the key objectives of 2008-09 was to develop the engineering skills required to take over full customer projects. This target was especially challenging given the operating conditions, operation and capital expedites have been drastically reduced to the very severe downturn of the automotive industry in 2008. The first paper concentrates on the processes how to identify, hire, train and retain people.

Flow noise caused by turbulent exhaust gas is one of the dominating noise sources on high performance turbo charged and naturally-aspirated engines. Due to the broad band and random character of this specific type of noise, an exact prediction based on Navier-Stokes equations is impractical to derive. Empirical approaches with varying quality levels were developed. These empirical approaches allow estimations of the flow noise from the early concept phase up to detailed design refinements and optimizations within the development. The main influence factors on flow noise such as temperature, mass flow and muffler design are outlined. The estimation of flow noise is based on empirical data and/or linear predictions with parametric single sources. Additional estimations are also based on more accurate, but also more time consuming, Computational Fluid Dynamics (CFD) codes for 3-dimensional flow optimization.

Downsizing concepts have led to an increasing use of turbochargers in gasoline engines. Turbochargers are available with different tolerances, although, small tolerances come at a high cost. Affordable turbochargers with bigger tolerances cause high frequency airborne and structure-borne noise which leads to turbocharger noises such as howling and whistling. Some noises are synchronic with the speed of the turbine or multiples of it. They span the audible range up to 16 kHz, provided that the dominance is below 5 kHz. Other noises are e.g. caused by the resonance of the bearing from the turbine. They are mainly between 500 Hz and 1 kHz. The exhaust system is one of the components which is excited; the radiated noise is then transferred into the cabin. Following Murphy's Law, when turbocharger noise occurs, it appears late within a development. One reason for this noise is part to part variation of the turbocharger.

Six Sigma was developed by Motorola in the 1980s as an enhancement of their Total Quality Management (TQM) approach focusing on quality improvement. Companies such as General Electric (GE) developed the concept even further and extended the application of Six Sigma tools to their entire business, including the development of new products, with a focus on both financial gain and customer satisfaction. Six Sigma, however, also offers a rigorous, data-driven procedure for process and product improvement and for the development of new products and processes using proven methods and tools taken from the Quality Management and Quality Engineering toolbox. Integration into the existing engineering culture and the application of these tools and concepts to a typical application at a leading global exhaust system supplier are outlined in this paper. The procedure which is used for measuring the surface radiated noise is analyzed in detail by the principles of Six Sigma.

Steel prices soared in the past years due to the increased demand on the Asian market. Due to difficult economic conditions of the automotive industry it is not possible to transfer expenses to the final customer. Reduction of steel is therefore required to compensate for higher steel prices. Whereas the underbody design space decreases in European vehicles, requirements are getting higher in terms of tailpipe noise and backpressure reduction. This leads to flat structures for mufflers which are integrated into the underbody to achieve as much inner volume for tailpipe noise damping as possible. That requires larger surfaces and results in a rise in costs, weight and radiated noise over surfaces. Additionally, original equipment manufacturers (OEM) require lightweight designs to meet carbon dioxide and consumption targets. Especially for Diesel applications the weight of exhaust systems is penalized by heavy Diesel particle filters.

The emitted noise of an exhaust system is divided into three different kinds of noise: Tailpipe noise, noise transmitted through the hanger into the cabin and surface radiated noise. This paper deals with the surface radiated noise which becomes more and more unmasked as the radiated sound power of other sources, e.g. of the tailpipe, decreases. Noise sources, the transfer path and the radiation of a structure are presented. A method for calculating and optimizing a structure with FEA (finite element analysis) is also part of this paper. An exhaust system is a complex dynamical system. Global eigenfrequencies of a whole exhaust system are below 200 Hz. A muffler moves then in rigid body motion and the radiated sound power is subjective not relevant. The main sound power is transferred through the hanger to the underbody. At higher frequencies the acoustical effects appear more local and are more effective in noise radiation.