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{{ACHeader
{{ACHeader
|area=2
|area=2
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=Abstract=
=Abstract=
This document contains the specifications of the Application  Challenge
This document contains the specifications of the Application  Challenge
proposed by the team of the Institute of Thermal Machinery, Cz?stochowa
proposed by the team of the Institute of Thermal Machinery, Częstochowa
University of Technology. This team performed LES  predictions  of  the
University of Technology. This team performed LES  predictions  of  the
Sandia Flame D within the EU-project MOLECULES FP5, Contract N° G4RD-CT-
Sandia Flame D within the EU-project MOLECULES FP5, Contract N° G4RD-CT-2000-00402.
2000-00402. The computations were performed with  the  BOFFIN-LES  code
The computations were performed with  the  BOFFIN-LES  code
developed at Imperial College by the group of Professor W.P. Jones. The
developed at Imperial College by the group of Professor W.P. Jones. The
software for the Conditional Moment Closure model used in  calculations
software for the Conditional Moment Closure model used in  calculations
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nor URANS predictions are included or analyzed.
nor URANS predictions are included or analyzed.


    To evaluate the sensitivity of the  subgrid-scale-modeling  quality  on
To evaluate the sensitivity of the  subgrid-scale-modeling  quality  on
    turbulent combustion predictions, two subgrid-scale models were tested:
turbulent combustion predictions, two subgrid-scale models were tested:
    the classical Smagorinsky  model and the  dynamic  version.  Turbulent
the classical Smagorinsky  model and the  dynamic  version.  Turbulent
    mixing features are then transmitted  to  the  reaction  front  through
mixing features are then transmitted  to  the  reaction  front  through
    turbulence/combustion  interaction  models  that  also  influence  the
turbulence/combustion  interaction  models  that  also  influence  the
    overall  combustion  process  predictions.  As  turbulence/combustion
overall  combustion  process  predictions.  As  turbulence/combustion
    interaction model, two different approaches were  studied:  the  simple
interaction model, two different approaches were  studied:  the  simple
    and efficient steady flamelet model and the  more  advanced  simplified
and efficient steady flamelet model and the  more  advanced  simplified
    Conditional  Moment  Closure-CMC  (In  simplified  CMC  approach,  the
Conditional  Moment  Closure-CMC  (In  simplified  CMC  approach,  the
    convective terms in physical space were  neglected,  making  the  model
convective terms in physical space were  neglected,  making  the  model
    very close to the unsteady flamelet approach).
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.


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/>
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{{ACContribs
{{ACContribs
|authors=Andrzej Boguslawski
|authors=Andrzej Boguslawski, Artur Tyliszczak
|organisation=Technical University of Czestochowa
|organisation=Częstochowa University of Technology
}}
}}
{{ACHeader
{{ACHeader

Latest revision as of 11:36, 14 January 2022

Front Page

Description

Test Data

CFD Simulations

Evaluation

Best Practice Advice

SANDIA Flame D

Application Area 2: Combustion

Application Challenge AC2-09

Abstract

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.



Contributed by: Andrzej Boguslawski, Artur Tyliszczak — Częstochowa University of Technology

Front Page

Description

Test Data

CFD Simulations

Evaluation

Best Practice Advice


© copyright ERCOFTAC 2011