Evaluation AC2-10: Difference between revisions
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==Comparison of CFD Results with Experimental Data== | ==Comparison of CFD Results with Experimental Data== | ||
===In-Cylinder Pressure=== | ===In-Cylinder Pressure=== | ||
The in-cylinder pressure curves are shown in Figure | The in-cylinder pressure curves are shown in [[Evaluation_AC2-10#figure18|Figure 18]]. All groups match the experimental data well. Only for the peak pressure one can observe deviations due to its sensitivity in respect to the boundary conditions. The peak pressure was typically overestimated by the simulations. The influence of the piston top-land crevice is shown considering the data obtained using Ansys CFX, where simulations were carried out with and without the crevice volume. The specific treatment of the crevice volume considering the different computational codes can be found in chapter \ref{sec:BC}. It was found, that the lower temperature inside the crevice is decreasing the overall in-cylinder temperature and hence the in-cylinder pressure. A detailed discussion about this deviation can be found in \cite{Janas2017,JanasDiss2017}. | ||
Revision as of 14:05, 16 October 2018
Internal combustion engine flows for motored operation
Application Challenge AC2-10 © copyright ERCOFTAC 2024
Evaluation
Comparison of CFD Results with Experimental Data
In-Cylinder Pressure
The in-cylinder pressure curves are shown in Figure 18. All groups match the experimental data well. Only for the peak pressure one can observe deviations due to its sensitivity in respect to the boundary conditions. The peak pressure was typically overestimated by the simulations. The influence of the piston top-land crevice is shown considering the data obtained using Ansys CFX, where simulations were carried out with and without the crevice volume. The specific treatment of the crevice volume considering the different computational codes can be found in chapter \ref{sec:BC}. It was found, that the lower temperature inside the crevice is decreasing the overall in-cylinder temperature and hence the in-cylinder pressure. A detailed discussion about this deviation can be found in \cite{Janas2017,JanasDiss2017}.
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| Figure 18: In-Cylinder pressure curve with enlargement at 0\,CAD |
Further, the trapped mass inside the cylinder after the intake valves are closed was calculated by all groups, see Table \ref{tab:trappedmass}. Unfortunately, the trapped mass was not determined experimentally wherefore no comparison can be performed here.
Contributed by: Carl Philip Ding,Rene Honza, Elias Baum, Andreas Dreizler — Fachgebiet Reaktive Strömungen und Messtechnik (RSM),Technische Universität Darmstadt, Germany
Contributed by: Brian Peterson — School of Engineering, University of Edinburgh, Scotland UK
Contributed by: Chao He , Wibke Leudesdorff, Guido Kuenne, Benjamin Böhm, Amsini Sadiki, Johannes Janicka — Fachgebiet Energie und Kraftwerkstechnik (EKT), Technische Universität Darmstadt, Germany
Contributed by: Peter Janas, Andreas Kempf — Institut für Verbrennung und Gasdynamik (IVG), Lehrstuhl für Fluiddynamik, Universität Duisburg-Essen, Germany
Contributed by: Stefan Buhl, Christian Hasse — Fachgebiet Simulation reaktiver Thermo-Fluid Systeme (STFS), Technische Universität Darmstadt, Germany; former: Professur Numerische Thermofluiddynamik (NTFD), Technische Universität Bergakademie Freiberg, Germany
© copyright ERCOFTAC 2018