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=Internal combustion engine flows for motored operation=
 
=Internal combustion engine flows for motored operation=
 
==Application Area 2: Combustion==
 
==Application Area 2: Combustion==
===Application Challenge AC2-09===
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===Application Challenge AC2-10===
 
=Abstract=
 
=Abstract=
This document contains the specifications of the Application  Challenge
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This test case provides data on the in-cylinder flow for an IC engine under motored operation. The Technische Universität Darmstadt engine features a typical design of a modern spark-ignition direct injection engine. It is an optically accessible single cylinder engine especially designed to provide well characterized boundary conditions and reproducible engine operation, a prerequisite for any comparison of experiments and simulations. The in-cylinder flow is characterized by various particle image velocimetry (PIV) techniques to provide measurements at high spatial and temporal resolution.
proposed by the team of the Institute of Thermal Machinery, Częstochowa
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The database for validation includes the first two statistical moments (mean and rms) of velocities, spatial flow structures and the temporal evolution of the flow field over the entire engine cycle in the central tumble plane. Information on the 3D flow is available within a volume up to 8 mm thick centered on the central tumble plane. Important boundary conditions such as the in-cylinder, intake- and exhaust-port pressures as well as temperatures are given. Simulation results obtained from three investigations using LES (Large Eddy Simulation) and hybrid URANS (unsteady Reynolds-averaged Navier-Stokes)/LES are presented and compared with the experimental results.
University of Technology. This team performed LES  predictions  of  the
 
Sandia Flame D within the EU-project MOLECULES FP5, Contract N° G4RD-CT-2000-00402.
 
The computations were performed with  the  BOFFIN-LES code
 
developed at Imperial College by the group of Professor W.P. Jones. The
 
software for the Conditional Moment Closure model used in  calculations
 
was developed by Professor E. Mastorakos at  Cambridge  University  and
 
implemented in the BOFFIN-LES code by the team  of  the  Institute  of
 
Thermal Machinery.
 
  
Sandia Flame D is a  widely  used  test  case  for  the  validation  of
 
numerical models of non-premixed  combustion.  This  flame  is  of  the
 
flamelet regime type in which  a  scale  separation  appears  i.e.  the
 
smallest scales of the  turbulent  flow,  the  Kolmogorov  scales,  are
 
significantly larger than the scales characteristic  for  the  reaction
 
zone.  Such  a  flame  facilitates  the  study  of  models  of
 
turbulence/chemistry interaction, allowing to separate the influence of
 
turbulence  and  turbulence/chemistry  interaction  models  from  the
 
influence of chemical kinetics models applied. Non-premixed  combustion
 
is limited by turbulent mixing and dominated by large scale structures.
 
The quality of unsteady flow dynamics predictions seems to  be  crucial
 
for the quality of the overall combustion process. Hence,  within  this
 
document attention is restricted to LES calculations and  neither  RANS
 
nor URANS predictions are included or analyzed.
 
  
To evaluate the sensitivity of the  subgrid-scale-modeling  quality  on
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<div id="figure1"></div>
turbulent combustion predictions, two subgrid-scale models were tested:
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{|align="center" width=650px
the classical Smagorinsky  model and the  dynamic  version. Turbulent
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|[[Image:AC2-10_engine.png]]
mixing features are then transmitted  to  the  reaction  front  through
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|-
turbulence/combustion  interaction  models  that  also  influence  the
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|align="left"|'''Figure 1:''' Photograph of the optically accessible engine. The in-cylinder volume is illuminated by the green laser-sheet used for the flow field measurements using particle image velocimetry (PIV).
overall  combustion  process  predictions.   As  turbulence/combustion
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|}
interaction model, two different approaches were  studied:  the simple
 
and efficient steady flamelet model and the more  advanced  simplified
 
Conditional  Moment  Closure-CMC  (In  simplified  CMC  approach,  the
 
convective terms in physical space were  neglected,  making  the  model
 
very close to the unsteady flamelet approach).
 
 
 
DOAPs for this type of reacting flow are  velocity,  mixture  fraction,
 
temperature and species concentration  mean  and  fluctuating  profiles
 
quantified by their local maxima.
 
 
<br/>
 
<br/>
 
----
 
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{{ACContribs
 
{{ACContribs
|authors=Andrzej Boguslawski, Artur Tyliszczak
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|authors=Carl Philip Ding, Rene Honza, Elias Baum, Benjamin Böhm, Andreas Dreizler
|organisation=Częstochowa University of Technology
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|organisation=Fachgebiet Reaktive Strömungen und Messtechnik (RSM),Technische Universit&auml;t Darmstadt, Germany
 +
}}
 +
{{ACContribs
 +
|authors=Brian Peterson
 +
|organisation=School of Engineering, University of Edinburgh, Scotland UK
 +
}}
 +
{{ACContribs
 +
|authors=Chao He, Wibke Leudesdorff, Guido Kuenne, Amsini Sadiki, Johannes Janicka
 +
|organisation=Fachgebiet Energie und Kraftwerkstechnik (EKT), Technische Universität Darmstadt, Germany
 +
}}
 +
{{ACContribs
 +
|authors=Peter Janas, Andreas Kempf
 +
|organisation=Institut für Verbrennung und Gasdynamik (IVG), Lehrstuhl für Fluiddynamik, Universität Duisburg-Essen, Germany
 +
}}
 +
{{ACContribs
 +
|authors=Stefan Buhl, Christian Hasse
 +
|organisation=Fachgebiet Simulation reaktiver Thermo-Fluid Systeme (STFS), Technische Universität Darmstadt, Germany; former: Professur Numerische Thermofluiddynamik (NTFD), Technische Universität Bergakademie Freiberg, Germany
 
}}
 
}}
 
{{ACHeader
 
{{ACHeader

Latest revision as of 15:47, 2 November 2018

Front Page

Description

Test Data

CFD Simulations

Evaluation

Best Practice Advice

Internal combustion engine flows for motored operation

Application Area 2: Combustion

Application Challenge AC2-10

Abstract

This test case provides data on the in-cylinder flow for an IC engine under motored operation. The Technische Universität Darmstadt engine features a typical design of a modern spark-ignition direct injection engine. It is an optically accessible single cylinder engine especially designed to provide well characterized boundary conditions and reproducible engine operation, a prerequisite for any comparison of experiments and simulations. The in-cylinder flow is characterized by various particle image velocimetry (PIV) techniques to provide measurements at high spatial and temporal resolution. The database for validation includes the first two statistical moments (mean and rms) of velocities, spatial flow structures and the temporal evolution of the flow field over the entire engine cycle in the central tumble plane. Information on the 3D flow is available within a volume up to 8 mm thick centered on the central tumble plane. Important boundary conditions such as the in-cylinder, intake- and exhaust-port pressures as well as temperatures are given. Simulation results obtained from three investigations using LES (Large Eddy Simulation) and hybrid URANS (unsteady Reynolds-averaged Navier-Stokes)/LES are presented and compared with the experimental results.


AC2-10 engine.png
Figure 1: Photograph of the optically accessible engine. The in-cylinder volume is illuminated by the green laser-sheet used for the flow field measurements using particle image velocimetry (PIV).




Contributed by: Carl Philip Ding, Rene Honza, Elias Baum, Benjamin Böhm, 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, 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

Front Page

Description

Test Data

CFD Simulations

Evaluation

Best Practice Advice


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