Coupling of ChemApp and OpenFOAM Messig, Danny; Rehm, Markus; Meyer, Bernd 19th May 2009
Contents 1 Introduction 2 Software OpenFOAM ChemApp Cantera 3 Coupling of chemistry packages and OpenFOAM 4 Testcases Plug flow reactor Coalgas 5 Conclusion / outlook 2
Contents 1 Introduction 2 Software OpenFOAM ChemApp Cantera 3 Coupling of chemistry packages and OpenFOAM 4 Testcases Plug flow reactor Coalgas 5 Conclusion / outlook 3
Introduction Aim of my work: Numerical simulation of an industrial coal gasifier with respect to the influence of mineral matter Disadvantages of commercial codes: Difficulties to incorporate surface mechanism Less transparency and flexibility (surface reaction models) Solution: Use of OpenFOAM [1] and the chemistry packages ChemApp and Cantera 4
Contents 1 Introduction 2 Software OpenFOAM ChemApp Cantera 3 Coupling of chemistry packages and OpenFOAM 4 Testcases Plug flow reactor Coalgas 5 Conclusion / outlook 5
Software OpenFOAM [1] Since 2004: public domain software for CFD calculations FOAM: Field Operation And Manipulation developed at Imperial College London since 1993 Download: http://www.openfoam.org Flexible set of C++ modules Structure of OpenFOAM: 6
Software ChemApp [2] Fortran-library (with C++ Interface) for the calculation of complex multicomponent, multiphase chemical equilibrium Thermochemical data for mineral matters (slag) available Operating principles: 7
Software Cantera [3] Open-source software package for kinetic controlled reactionrates and equilibrium calculations Interfaces for MATLAB, Python, C++ or Fortran 8
Contents 1 Introduction 2 Software OpenFOAM ChemApp Cantera 3 Coupling of chemistry packages and OpenFOAM 4 Testcases Plug flow reactor Coalgas 5 Conclusion / outlook 9
Coupling of chemistry packages and OpenFOAM Overview [4] Only for homogenous phases 10
Contents 1 Introduction 2 Software OpenFOAM ChemApp Cantera 3 Coupling of chemistry packages and OpenFOAM 4 Testcases Plug flow reactor Coalgas 5 Conclusion / outlook 11
Plug flow reactor (PFR) Data Premixed combustible mixture at inlet: Y H2 = 0.009, Y O2 = 0.026, Y Ar = 0.965, T = 1600 K, p = 1 bar Tube idealised as 2D-domain x max = 1 m, y max = 0.1 m, 10 100 cells 12
PFR Solver settings: SIMPLE algorithm k-ɛ turbulence model Axisymmetric and steady state Available 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) 13
PFR Temperature profile along the axis of PFR Temperatures on outlet nearly identical, differences results from different thermodata between Chemkin and other CP Discrepancy between kinetic und equal calculations determined 14
PFR y H2 profile along the axis of PFR Concentration on outlet nearly identical Differences between kinetic und ideal calculations are due to coarse grid 15
Coalgas Settings: (refering to Sydney Bluff-body Flame (HM1)[5]) Diameter: D jet = 3.6mm; D bluffbody = 50mm Grid: x max = 0.54mm, y max = 0.075mm, 1095 cells Turbulence: 8.5 % (2.5%) turbulence intensity, 0.135 mm (5.625 mm) mixing length for jet (co-flow) Velocity U jet = 118m/s, U coflow = 40m/s Pressure: 30 bar Temperature: 900 K at inlets 16
Coalgas Fuel Coalgas has same quantity of elements and heat of combustion like a real coal at 900 K and 30 bar Massfractions of coalgas: Y CH4 0.13, Y H2 0.05, Y N2 0.02, Y H2 O 0.21, Y CO 0.34, Y CO2 0.25 Flowsheet: 17
Coalgas Fluent vs. OpenFOAM Fluent settings: SIMPLE algorithm k-ɛ turbulence model Non-premixed combustion with equilibrium chemistry (PDF, 17 species) Axisymmetric and steady state OpenFOAM settings: SIMPLE algorithm k-ɛ turbulence model Equilibrium calculations with Cantera and ChemApp (53/77 species) Axisymmetric and steady state 18
Coalgas Points of data generation for comparison 19
Coalgas Results: Temperature profiles Curves show same behaviour, but peak values differ because of different transport data and number of species 20
Coalgas Results: y CO -profiles Curves show same behaviour 21
Contents 1 Introduction 2 Software OpenFOAM ChemApp Cantera 3 Coupling of chemistry packages and OpenFOAM 4 Testcases Plug flow reactor Coalgas 5 Conclusion / outlook 22
Conclusion / outlook Conclusion: Coupling of ChemApp and OpenFOAM successful Equilibrium calculations in OpenFOAM could be done with ChemApp 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 under development by B.Gschaider [6]) with ChemApp for the influence of mineral matter 23
Acknowledgement The results described above were obtained in the research project HotVeGas. The project was supported with public funding by the German Federal Ministry of Economics and Technology (Project ID 0327773B) 24
Thank you for your attention! Questions? 25
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 into openfoam. 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-Body Stabilized Nonpremixed Flames. Combustion and Flame, 114(1-2):119 148, 1998. 26
Literatur II [6] Strömungsforschungs GmbH, http://www.ice-sf.at/cfd.shtml. 27