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Calculating the bearing reliability and behavior is one of the primary tasks which have to be performed to define the main dimensions of the cranktrain of an internal combustion engine. Since the bearing results are essential for the pre-layout of the cranktrain, the conclusion on the bearing safety should be met as early as possible. Therefore detailed simulations like T-EHD or EHD analysis may not be applied to define the dimensions in such an early development phase. In the frame of this study a prediction methodology, based on a HD bearing approach, for bearing reliability of inline-4 crankshafts of passenger cars is proposed. In this way not only the design phase is shortened but also achieving the optimal solution is simplified. Moreover the requirement of a CAD model is eliminated for the preliminary design phase. The influencing parameters on the bearing behavior are first selected and divided into two groups: geometry and loading.

Over the last decades, the use of computers has become an integral part of the engine development process. Computer-based tools are increasingly used in the design process, and especially the layout of the various subsystems is conducted by means of simulation models. Computer-aided engineering plays a central role e.g. in the design of the combustion process as well as with regards to work performed in the area of engine mechanics, where CFD, FEM, and MBS are applied. As a parallel trend, it can be observed that various engine performance characteristics such as e.g. the specific power output and the power-to-weight ratio have undergone an enormous increase, a trend which to some extent counteracts the increase in safety against malfunction and failure. As yet, due to the constant need for further optimization, mechanical testing and verification processes have not become redundant, and it is assumed that they will remain indispensable for the foreseeable future.

Modern powertrain development is targeting to meet challenging, to some degrees contradictory development goals in a short timeframe. Looking to a development time schedule of 36 months from concept to SOP, it becomes a prerequisite that unnecessary design loops have to be avoided by all means. Now, in addition, the experimental development work has to be conducted more efficiently than in the past. In recent years methods for an efficient design process have been successfully applied. Testing and vehicle application work can take advantage of methods empowered by model based approaches. Today, models with different levels of detail are able to significantly improve nearly every development phase. Supported by standardized and automated test bench and vehicle procedures an efficient and comprehensive development process can be established and utilized, which is also necessary to tackle growing complexity.

The new opoc™ diesel engine concept was presented at the SAE 2005 World Congress [1]. Exceptional power density of >1hp/lb and >40% efficiency have been predicted for the 2-stroke opoc™ diesel engine concept. Intensive CAE simulations have been performed during the concept and design phase in order to define the baseline scavenging and combustion parameters, such as port timing, turbocharger configuration and fuel injection nozzle design. Under a DARPA contract, first prototype engines have been built and have undergone a validation testing program. The main goal of the first testing phase was to demonstrate the power output capability of the new engine concept. In close relationship and interaction of testing and CAE simulation, the uniflow scavenging process and parameters of the special diesel direct side injection have been optimized. This paper discusses the latest results of the opoc engine development.

Nowadays internal combustion engine design is characterized by a faster development time with increased levels of quality, NVH, specific power and lower weight all being demanded at a lower production cost. This requires a new and systemic design management from the outset of the concept to SOP (Start of Production). The design for Six Sigma (DFSS) process is the surest way to achieve the above mentioned development goals. Within a Six Sigma approach, manufacturing and serial production issues are considered from the beginning of the development phase. Based on examples, the methodology will be explained in single steps. The explanation will include QFD, FMEA (product and process), scorecards, DOE and kneading process with its tolerance analysis and process capability investigations. The use of these different tools for each phase of the design process will be described.

The sound quality and performance of an automotive engine are both significantly influenced by the “air-to-air” system, i.e., the intake system, the exhaust system, and the engine gas dynamics. Only a full systems approach can result in an optimized air-to-air system, which fulfills engine performance requirements, overall sound pressure level targets for airborne vehicle noise, as well as sound quality demands. This paper describes an approach, which considers the intake system, engine, and exhaust system within one CAE model that can be utilized for engine performance calculations as well as acoustic simulations. Examples comparing simulated and measured sound are discussed. Finally, the simulated sound (e.g., at the tailpipe of the exhaust system) is combined with an interior noise simulation technique to evaluate its influence inside the vehicle's interior.