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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 typically 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 resolutions.  
This test case provides data on the in-cylinder flow for an IC engine under motored operation. The Technische Universität Darmstadt engine features a typically 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 resolutions.  
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 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.
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 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.
This document contains the specifications of the Application  Challenge
proposed by the team of the Institute of Thermal Machinery, Częstochowa
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
turbulent combustion predictions, two subgrid-scale models were tested:
the classical Smagorinsky  model and the  dynamic  version.  Turbulent
mixing features are then transmitted  to  the  reaction  front  through
turbulence/combustion  interaction  models  that  also  influence  the
overall  combustion  process  predictions.  As  turbulence/combustion
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.
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Revision as of 12:09, 9 October 2018

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Description

Test Data

CFD Simulations

Evaluation

Best Practice Advice

Internal combustion engine flows for motored operation

Application Area 2: Combustion

Application Challenge AC2-09

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 typically 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 resolutions. 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 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.


Contributed by: Carl Philip Ding — Technische Universität Darmstadt

Front Page

Description

Test Data

CFD Simulations

Evaluation

Best Practice Advice


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