Coupling of ChemApp and OpenFOAM

Messig, Danny; Rehm, Markus; Meyer, Bernd

19th May 2009

Contents

1 Introduction2 Software

OpenFOAMChemAppCantera

3 Coupling of chemistry packages and OpenFOAM4 Testcases

Plug flow reactorCoalgas

5 Conclusion / outlook

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Contents

1 Introduction2 Software

OpenFOAMChemAppCantera

3 Coupling of chemistry packages and OpenFOAM4 Testcases

Plug flow reactorCoalgas

5 Conclusion / outlook

3

Introduction

Aim of my work:

Numerical simulation of an industrial coal gasifier with respectto the influence of mineral matter

Disadvantages of commercial codes:Difficulties to incorporate surface mechanismLess transparency and flexibility (surface reaction models)

Solution:Use of OpenFOAM [1] and the chemistry packages ChemAppand Cantera

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Contents

1 Introduction2 Software

OpenFOAMChemAppCantera

3 Coupling of chemistry packages and OpenFOAM4 Testcases

Plug flow reactorCoalgas

5 Conclusion / outlook

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Software

OpenFOAM [1]Since 2004: public domain software for CFD calculations

FOAM: Field Operation And Manipulationdeveloped at Imperial College London since 1993Download: http://www.openfoam.org

Flexible set of C++ modulesStructure of OpenFOAM:

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Software

ChemApp [2]Fortran-library (with C++ Interface) for the calculation ofcomplex multicomponent, multiphase chemical equilibriumThermochemical data for mineral matters (slag) availableOperating principles:

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Software

Cantera [3]Open-source software package for kinetic controlledreactionrates and equilibrium calculationsInterfaces for MATLAB, Python, C++ or Fortran

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Contents

1 Introduction2 Software

OpenFOAMChemAppCantera

3 Coupling of chemistry packages and OpenFOAM4 Testcases

Plug flow reactorCoalgas

5 Conclusion / outlook

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Coupling of chemistry packages and OpenFOAM

Overview [4]

Only for homogenous phases

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Contents

1 Introduction2 Software

OpenFOAMChemAppCantera

3 Coupling of chemistry packages and OpenFOAM4 Testcases

Plug flow reactorCoalgas

5 Conclusion / outlook

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Plug flow reactor (PFR)

DataPremixed combustible mixture at inlet: YH2 = 0.009, YO2 =0.026, YAr = 0.965, T = 1600 K, p = 1 barTube idealised as 2D-domainxmax = 1 m, ymax = 0.1 m, 10× 100 cells

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PFR

Solver settings:SIMPLE algorithmk-ε turbulence modelAxisymmetric and steady stateAvailable chemistry packages (CP):

Kinetic controlled reactions with Cantera (cantera-kinetic)Equilibrium calculations with Cantera (cantera-equal)Equilibrium calculations with ChemApp (chemapp)For validation: ideal calculations with Chemkin (chemkin)

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PFR

Temperature profile along the axis of PFR

Temperatures on outlet nearly identical, differences resultsfrom different thermodata between Chemkin and other CPDiscrepancy between kinetic und equal calculations determined

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PFR

yH2 profile along the axis of PFR

Concentration on outlet nearly identicalDifferences between kinetic und ideal calculations are due tocoarse grid

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Coalgas

Settings: (refering to Sydney Bluff-body Flame (HM1)[5])Diameter: Djet = 3.6mm; Dbluffbody = 50mmGrid: xmax = 0.54mm, ymax = 0.075mm, 1095 cellsTurbulence: 8.5 % (2.5%) turbulence intensity, 0.135 mm(5.625 mm) mixing length for jet (co-flow)Velocity Ujet = 118m/s, Ucoflow = 40m/sPressure: 30 barTemperature: 900 K at inlets

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Coalgas

FuelCoalgas has same quantity of elements and heat of combustionlike a real coal at 900 K and 30 barMassfractions of coalgas: YCH4 ≈ 0.13, YH2 ≈ 0.05,YN2 ≈ 0.02, YH2O ≈ 0.21, YCO ≈ 0.34, YCO2 ≈ 0.25Flowsheet:

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Coalgas

Fluent vs. OpenFOAMFluent settings:

SIMPLE algorithmk-ε turbulence modelNon-premixed combustion with equilibrium chemistry (PDF,17 species)Axisymmetric and steady state

OpenFOAM settings:SIMPLE algorithmk-ε turbulence modelEquilibrium calculations with Cantera and ChemApp (53/77species)Axisymmetric and steady state

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Coalgas

Points of data generation for comparison

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Coalgas

Results: Temperature profiles

Curves show same behaviour, but peak values differ because ofdifferent transport data and number of species

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Coalgas

Results: yCO-profiles

Curves show same behaviour

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Contents

1 Introduction2 Software

OpenFOAMChemAppCantera

3 Coupling of chemistry packages and OpenFOAM4 Testcases

Plug flow reactorCoalgas

5 Conclusion / outlook

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Conclusion / outlook

Conclusion:

Coupling of ChemApp and OpenFOAM successful⇒ Equilibrium calculations in OpenFOAM could be done withChemApp and Cantera (Cantera faster)Equilibrium calculations mostly inappropriate for gas-phase⇒ Necessity of coupling kinetic controlled phases(e.g. gas phase) with phases solved by equilibrium calculations(e.g. slag, since no kinetic data is available)

Outlook:

Coupling of coalFoam (solver for coal gasification is underdevelopment by B.Gschaider [6]) with ChemApp for theinfluence of mineral matter

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Acknowledgement

The results described above were obtainedin the research project „HotVeGas“.

The project was supported with public funding by theGerman Federal Ministry of Economics and Technology(Project ID 0327773B)

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Thank you for your attention!Questions?

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Literatur I

[1] OpenFOAM, www.opencfd.co.uk/openfoam/.

[2] http://gttserv.lth.rwth-aachen.de/˜cg/software/chemapp.

[3] DG Goodwin.Cantera: Object-oriented software for reacting flows.Technical report, California Institute of Technology, 2002.

[4] Gschaider B., Rehm M., Seifert P., Meyer B.Implementation of an alternative chemistry library intoopenfoam.In Open Source CFD International Conference 2008, Berlin,2008.

[5] BB Dally, AR Masri, RS Barlow, and GJ Fiechtner.Instantaneous and Mean Compositional Structure of Bluff-BodyStabilized Nonpremixed Flames.Combustion and Flame, 114(1-2):119–148, 1998.

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Literatur II

[6] Strömungsforschungs GmbH, http://www.ice-sf.at/cfd.shtml.

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