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An effective way to reduce greenhouse gas emissions (GHGs) is to use rurally produced straight jatropha oil as a substitute for diesel fuel. However, the different physical and chemical properties of straight vegetable oils (SVOs) require a customized setup of the combustion engine, particularly of the injection timing and quantity. Therefore, this study demonstrates the differences in the injection and combustion processes of jatropha oil compared to diesel fuel, particularly in terms of its compatibility with exhaust gas recirculation (EGR). A 2.2 l common-rail diesel engine with a two-stage turbocharging concept was used for testing. To examine the differences in injection rate shaping of diesel fuel and jatropha oil, the injector was tested with an injection rate analyzer using both the fuels. To investigate the combustion process, the engine was mounted at an engine test bench and equipped with a cylinder pressure indication system.

New trends in the development of combustion engines lead to changed engine operating conditions which also result in changed loads of the engine parts and functional components. The application of regenerative fuels and new exhaust after- treatment systems can for example lead to an increased input of fuel into the engine oil. Oil dilution is an issue that impacts the engine operation and life cycle and therefore gains importance during the development process of combustion engines. In order to improve oil dilution to preclude destructive amounts of fuel in the oil it is necessary to investigate and optimize the fuel in oil sorption and desorption processes. At the University of Applied Sciences Regensburg a new measurement technique has been developed that realizes the online analysis of the fuel quantity in the engine oil.

The emission reduction potential of high boost and high injection pressures was investigated on a 4-cylinder small bore diesel engine at high rates of exhaust gas recirculation. For this reason an external boosting system was built up, which allowed to generate the desired boost pressure independent from the engine's operating point. In order to simulate conditions comparable to a real turbocharged engine, also the influence of the turbine on the exhaust back pressure was considered. The whole measurement campaign was carried out at two load points (low- and mid-load), which represent characteristic engine operating points of the Urban Driving Cycle (UDC). On the one hand could be shown, that there is an enormous potential in the reduction of particulate matter (PM) up to 75 % and of carbon monoxide (CO) up to 15 % at the mid-load point by increasing the boost pressure.

The presentation describes the aerodynamic development and optimization process of the three different new models of the Audi A6/A7 family. The body types of these three models represent the three classic aerodynamic body types squareback, notchback and fastback. A short introduction of the flow structures of these different body types is given and their effect on the vehicle aerodynamic is described. In order to achieve good aerodynamic performance, the integration into the development process of the knowledge about these flow phenomena and the breakdown of the aerodynamic resistance into its components friction- and pressure drag as well as the induced drag is very important. The presentation illustrates how this is realized within the aerodynamic development process at Audi. It describes how the results of CFD simulations are combined with wind tunnel measurements and how the information about the different flow phenomena were used to achieve an aerodynamic improvement.

The paper describes the aerodynamic development and optimization process of the three different new models of the Audi A6/A7 family. The body types of these three models represent the three classic aerodynamic body types squareback, notchback and fastback. A short introduction of the flow structures of these different body types is given and their effect on the vehicle aerodynamic is described. In order to achieve good aerodynamic performance, the integration into the development process of the knowledge about these flow phenomena and the breakdown of the aerodynamic resistance into its components friction- and pressure drag as well as the induced drag is very important. The paper illustrates how this is realized within the aerodynamic development process at Audi. It describes how the results of CFD simulations are combined with wind tunnel measurements and how the information about the different flow phenomena were used to achieve an aerodynamic improvement.

Within in the scope of a road load investigation project at FKFS, the influence of rotating wheels on the road load of a passenger car was investigated. For this purpose an approach was developed to measure the ventilation resistance of a spinning wheel. This approach enables a comparison of different wheel sizes and rim designs. Together with aerodynamic drag measurements in the wind tunnel it is possible to evaluate different wheel configurations with respect to their contribution to the road load. The measuring approach and results of performed measurements are shown in this paper.

This paper introduces a driving-torque measurement method for the determination of vehicle road load and its components. To increase the accuracy, the torque measurements are combined with rolling resistance measurements performed with a specially developed trailer. This method is a strictly experimental approach and does not use any mathematical models. The experimental techniques are described as well as the proceedings to compare test stand and road measurements. The results that are shown prove that this method is suitable for the investigation of single road load components. Furthermore, the comparison of different rolling resistance measurement devices shows the potential of the measurement trailer and the necessity to perform rolling resistance measurements on real road surfaces and not solely on test stands.

In recent years we have seen drastic improvements of the accuracy of wheel force transducer (WFT) systems /1, 2 and 3/. These systems in most cases are calibrated just statically. What is the dynamic behaviour of the sensor? What can we expect towards the accuracy of the measured loads on real road surfaces as they are influenced by a number of parameters? In the present paper quantitative results are reported out of a broad investigation of the effects of the following parameters road surface, rim stiffness, tire air pressure, velocity and wet road conditions. The unique Wheel and Tire Testing Vehicle (“Universal Skid Resistance Measurement Device”) of Stuttgart University was used for the measurements on two highways. The WFT-signals are referenced to the multiaxial force sensing of this vehicle. These findings are compared to results derived from a rolling road flatbelt test stand reported in /6/.