Description AC2-10
Internal combustion engine flows for motored operation
Application Challenge AC2-10 © copyright ERCOFTAC 2024
Abbreviations
ALE | Arbitrary Lagrangian-Eulerian |
aTDC | after top dead center |
bTDC | before top dead center |
BDC | bottom dead center |
CA | crank angle |
CAD | crank angle degreeCCD charge-coupled device |
CCV | cycle-to-cycle variation |
CDS | central differencing scheme |
CFD | computational fluid dynamics |
CFL | Courant-Friedrichs-Lewy |
ENO | Essentially Non-Oscillatory |
ERG | exhaust-gas-recirculation |
EVC | exhaust valve closing |
EVO | exhaust valve opening |
HS-PIV | high speed particle image velocimetry |
IC | internal combustion |
IVC | intake valve closing |
IVO | intake valve opening |
LES | large eddy simulation |
MRV | magnetic resonance velocimetry |
PIV | particle image velocimetry |
POV | field-of-view |
QSOU | quasi-second-order upwind |
QUICK | Quadratic Upwind Interpolation for Convective Kinematics |
RANS | Reynolds-averaged Navier-Stokes |
RMS | root mean square |
RPM | rounds per minute |
SAS | scale-adaptive simulation |
SRS | scale-resolving simulation |
SST | shear stress transport |
TDC | top dead center |
TUBF | Technische Universität Bergakademie Freiberg |
TUD | Technische Universität Darmstadt |
TVD | total variation diminishing |
UDE | Universität Duisburg-Essen |
URANS | unsteady Reynolds-averaged Navier-Stokes |
WG | wall-guided |
Description
Introduction
The TU Darmstadt engine is an optically accessible single cylinder spark-ignition direct injection engine. It is embedded in an especially designed test bench to provide well characterized boundary conditions and reproducible engine operation. A reproducible engine operation is needed to characterize the variety of in-cylinder processes and is a prerequisite for any comparison of experiments and simulations. The in-cylinder processes are characterized using advanced laser-diagnostics to provide measurements at high spatial and temporal resolutions. The aim of this effort is, to build up a comprehensive data set
- to give insights into the underlying physics for a better understanding of the relevant in-cylinder processes and
- for the validation of CFD simulations especially for large eddy simulations (LES).
The validation of CFD simulations for IC engines requires a variety of physical and chemical quantities and a comprehensive dataset consisting of systematic hierarchical sub-datasets. Such a validation sequence typically starts with the comparison of the non-reacting flow field and increases complexity stepwise by the addition of processes such as, combustion of perfect homogeneous air/fuel mixtures, in-cylinder mixture preparation using direct-injection and combustion of these mixtures. The presented test case is part of an ongoing effort at TU Darmstadt aiming for a detailed characterization of engine combustion addressing the non-reacting flow field \cite{Baum2014,Baum2013,Zentgraf2016}, combustion of homogenous air/fuel mixtures \cite{Peterson2015} and mixture preparation by direct injection \cite{Peterson2017}. The here presented test-case includes the sub-dataset on the non-reacting flow field (motored engine operation) providing a comprehensive data set on the first two statistical moments of flow velocities, spatial flow structures, and the dynamics of the turbulent in-cylinder flow field. The following sections summarize the work which has been presented within \cite{Baum2014}. Further details on the experimental setup and flow field data can be found in \cite{Baum2014,Baum2013,Zentgraf2016}. Additionally, simulation results obtained from three investigations using LES (Large Eddy Simulation) and hybrid URANS (unsteady Reynolds-averaged Navier-Stokes)/LES described in section \ref{sec:simulation} are presented and compared with experimental data, see section \ref{sec:evaluation}.
Relevance to industrial sector
Design or assessment parameters
Engine test bench
Engine
Flow physics and Fluid Dynamics Data
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