Eberspächer (Germany)

We developed a high transmission Hollow-core fiber (HCF) with 1mm ID that supports 97% absolute transmission. We were able to achieve about 30 times spectral broadening of 11mJ, 1.5ps pulses from a 275W, 25 kHz InnoSlab multi-pass amplifier with 90% fiber transmission. The spectrum achieved with Kr at 1 bar supports a 50fs TL bandwidth.

The tightening of the emission regulation over the last decades has a significant influence on the size as well as on the complexity of the exhaust systems for heavy duty vehicles. Starting with the introduction of a diesel oxidation catalyst (DOC) to reduce hydrocarbons (HC) and carbon monoxide (CO) emissions according to emissions legislation, with the introduction of EU4 emission limits for heavy duty commercial vehicles the more complex SCR technique took place within Europe. The application of the SCR technology provides an excellent potential for reducing NOx emissions of commercial vehicles.

<div class="section abstract"><div class="htmlview paragraph">Although the technology of combustion engines is reasonably well developed, the degree of efficiency is considerably low. Considerable amount of the energy of around 35 % is lost as exhaust waste heat, and up to 30 % is dissipated in the cooling circuits. Due to this, thermal recuperation has a great potential for raising the efficiency of combustion engines. In order to meet the ever-increasing consumer demand for higher fuel economy, and to conform to more stringent governmental regulations, auto manufacturers have increasingly looked at thermoelectric materials as a potential method to recover some of that waste heat and improve the overall efficiency of their vehicle fleets. Seeking new possibilities to make vehicles greener and more efficient, the industry wants to use the waste heat which passes through the exhaust system almost completely unused in the past. The combination of heat exchanger and thermoelectric material integrated into the vehicle environment results in high demands on design, size & dimensioning of the thermoelectric generator system. As a company specializing in the manufacture of exhaust systems for the automotive industry, Eberspächer Exhaust Systems of Americas is uniquely well-positioned to develop and integrate an in-line system for the capture and conversion of thermal energy into electrical energy, and to account for the effects of the heat exchanger on the rest of the exhaust system and engine. In this paper, the stages of the thermal and mechanical design of heat exchanger, material selection, analytical simulations of thermal, contact phenomena, finite element methodology used, physical TEG prototype fabrication and testing stages involved in the development of a 1000 Watt thermoelectric generator (TEG) for a diesel engine of a military tank are explained in detail.</div></div>

<div class="section abstract"><div class="htmlview paragraph">Exhaust and muffler noise is a challenging problem in the transport industry. While the main purpose of the system is to reduce the intensity of the acoustic pulses originating from the engine exhaust valves, the back pressure induced by these systems must be kept to a minimum to guarantee maximum performance of the engine. Emitted noise levels have to ensure comfort of the passengers and must respect community noise regulations. In addition, the exhaust noise plays an important role in the brand image of vehicles, especially with sports car where it must be tuned to be “musical”. However, to achieve such performances, muffler and exhaust designs have become quite complex, often leading to the rise of undesired self-induced noise. Traditional purely acoustic solvers, like Boundary Element Methods (BEM), have been applied quite successfully to achieve the required acoustic tuning. However, they fail at predicting all of flow-induced noise, as well as non-linear noise dissipation mechanisms. A natural candidate for this type of problem is the use of a Lattice-Boltzmann Method (LBM) solver as a CFD tool. It has already been successfully applied and validated to quantify self-induced noise of mufflers as well as complex acoustic devices performance like acoustic liners. In this paper, a muffler baseline geometry self-induced noise is assessed using the commercial LBM solver PowerFLOW. Noise generation mechanisms are identified and design modifications are proposed to atone it. The given baseline and iterations designs noise mechanisms are analyzed and the obtained noise reductions are compared and discussed.</div></div>

<div class="section abstract"><div class="htmlview paragraph">In order to have a robust exhaust system design a comprehensive durability analysis is required. This durability analysis should include thermal loads, engine vibration loading, and proving ground road loads. The dynamic performance evaluation in exhaust system development is a valuable tool to identify the best design alternative. The finite element analysis (FEA) applications in the design of automotive exhaust system have become an indispensable tool. Both the cost and cycle of the product development benefit from its usages. This paper presents a robust design procedure for the dynamic performance of exhaust system in a passenger vehicle. For dynamic analyses it is essential that the complete exhaust assembly is modeled, including manifold, a representation of the engine, and a flex decouple model. This is because dynamic excitation is predominantly comprised of unbalanced forces within the engine, which is transmitted to the exhaust system through the flex decoupling element. This paper presents the dynamic performance for the complete exhaust system and a DOE investigation approach for stiffness study of flex decouple. The first part of paper describes the dynamic performance evaluation of exhaust system in frequency domain and correlation of FEA model to experimental data. The correlation and updating of FEA is to ensure the representativeness of the FE model. The second part is the DOE study of the decoupling flex pipe to define the optimal stiffness parameters in order to reach the specified durability targets in exhaust system. In this paper all the employed methodology will be discussed in details.</div></div>