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2011-09-11
Technical Paper
2011-24-0205
Josef Schaeffler, Daniel Alberer, Klaus Siegfried Oppenauer, Luigi del Re
Modeling the soot emissions of a Diesel engine is a challenge. Although it was part of many works before, it is still not a solved issue and has a substantial potential for improvement. A major problem is the presence of two competing effects during combustion, soot formation and soot oxidation, whereas only the cumulative difference of these effects can be measured in the exhaust. There is a wide consensus that it is sensible to design crank angle resolved models for both effects. Indeed, many authors propose crank angle based soot models which are mostly based on detailed first principles based structures, e.g. spray models, engine process calculations etc. Although these models are appealing from a theoretical point of view, they are all lacking of the required measurement information to validate all the complex model parts. Finally, most parts of the model remain at their assumed values and only a few parameters are used for calibration.
2011-09-11
Journal Article
2011-24-0020
Klaus Siegfried Oppenauer, Daniel Alberer, Luigi del Re
Computation of combustion, in particular of emissions over crank angle, relies on chemical oriented models. In some cases, chemical equilibrium can be assumed, as chemical reaction time scales tend to be fast compared to the crank rotation, so the rather complex reaction kinetics can be neglected. For engine process calculation based on the measured cylinder pressure chemical equilibrium concentrations are needed for every crank angle or calculation time step. On the one hand the equilibrium concentrations are necessary for estimating the thermodynamic properties of the working gas (internal energy and specific gas constant) which are needed for deriving the energy release (burn rate) and on the other hand the obtained concentrations are inputs for crank angle based soot and nitric oxygen emission models which depends also on the engine process calculation results.
2007-04-16
Technical Paper
2007-01-0864
Markus Hirsch, Daniel Alberer, Luigi del Re, Clemens Schelhaas
Two-wheel vehicles are becoming continuously more important in Europe, but their spread is accompanied by an increase in security concerns due a number of reasons. These include stability problems during braking, and in particular curve braking, which is much more critical than in 4-wheel vehicles. These stability problems are strongly influenced by the behavior of the driver, in particular by his braking and steering activity. In this work we present a curve-safe ABS control, and analyze the role of the driver by a simulation model. It turns out that the demands on the driver in terms of stability control vary strongly with the braking behavior.
Viewing 1 to 3 of 3