0
Research Papers: Gas Turbines: Combustion, Fuels, and Emissions

Sensitivity of the Numerical Prediction of Turbulent Combustion Dynamics in the LIMOUSINE Combustor

[+] Author and Article Information
Mina Shahi

e-mail: m.shahi@utwente.nl

J. C. Roman Casado

Laboratory of Thermal Engineering Enschede,
Faculty of Engineering Technology,
University of Twente,
Enschede 7500 AE, Netherlands

Thomas Sponfeldner

Department of Mechanical Engineering,
Imperial College London,
London SW7 2AZ, UK

Contributed by the Combustion and Fuels Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received July 15, 2013; final manuscript received August 12, 2013; published online October 28, 2013. Editor: David Wisler.

J. Eng. Gas Turbines Power 136(2), 021504 (Oct 28, 2013) (12 pages) Paper No: GTP-13-1261; doi: 10.1115/1.4025373 History: Received July 15, 2013; Revised August 12, 2013

The objective of this study is to investigate the sensitivity and accuracy of the reaction flow-field prediction for the LIMOUSINE combustor with regard to choices in computational mesh and turbulent combustion model. The LIMOUSINE combustor is a partially premixed, bluff body-stabilized natural gas combustor designed to operate at 40–80 kW and atmospheric pressure and used to study combustion instabilities. The transient simulation of a turbulent combusting flow with the purpose to study thermoacoustic instabilities is a very time-consuming process. For that reason, the meshing approach leading to accurate numerical prediction, known sensitivity, and minimized amount of mesh elements is important. Since the numerical dissipation (and dispersion) is highly dependent on, and affected by, the geometrical mesh quality, it is of high importance to control the mesh distribution and element size across the computational domain. Typically, the structural mesh topology allows using much fewer grid elements compared to the unstructured grid; however, an unstructured mesh is favorable for flows in complex geometries. To explore computational stability and accuracy, the numerical dissipation of the cold flow with mixing of fuel and air is studied first in the absence of the combustion process. Thereafter, the studies are extended to combustible flows using standard available ansys-cfx combustion models. To validate the predicted variable fields of the combustor's transient reactive flows, the numerical results for dynamic pressure and temperature variations, resolved under structured and unstructured mesh conditions, are compared with experimental data. The obtained results show minor dependence on the used mesh in the velocity and pressure profiles of the investigated grids under nonreacting conditions. More significant differences are observed in the mixing behavior of air and fuel flows. Here, the numerical dissipation of the (unstructured) tetrahedral mesh topology is higher than in the case of the (structured) hexahedral mesh. For that reason, the combusting flow, resolved with the use of the hexahedral mesh, presents better agreement with experimental data and demands less computational effort. Finally, in the paper, the performance of the combustion model for reacting flow is presented and the main issues of the applied combustion modeling are reviewed.

Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Weatherill, N. P., 1988, “A Method for Generating Irregular Computational Grids in Multiply Connected Planar Domains,” Int. J. Numer. Methods Fluids, 8(2), pp. 181–197. [CrossRef]
Koomullil, R., Soni, B., and Singh, R., 2008, “A Comprehensive Generalized Mesh System for CFD Applications,” Math. Comput. Simul., 78(5–6), pp. 605–617. [CrossRef]
Mavriplis, D. J., 1997, “Unstructured Grid Techniques,” Ann. Rev. Fluid Mech., 29, pp. 473–514. [CrossRef]
Kikuchi, N., 1986, “Adaptive Grid-Design Methods for Finite Element Analysis,” Comput. Methods Appl. Mech. Eng., 55(1–2). pp. 129–160. [CrossRef]
Beam, R. M., and Warming, R., 1982, “Implicit Numerical Method for the Compressible Navier–Stokes and Euler Equations,” lecture notes, Von Karman Institute for Fluid Dynamics, Sint-Genesius-Rode, Belgium.
Caughey, D. A., and Hafez, M. M., 1994, Frontiers of Computational Fluid Dynamics, Wiley, New York.
Çete, A. R., Yükselen, M. A., and Kaynak, Ü., 2008, “A Unifying Grid Approach for Solving Potential Flows Applicable to Structured and Unstructured Grid Configurations,” Comput. Fluids, 37(1), pp. 35–50. [CrossRef]
Hansen, R. P., and Forsythe, J. R., 2003, “A Comparison of Structured and Unstructured Grid Solutions for Flow Over a Circular Cylinder,” Proceedings of the 2003 DoD User Group Conference, Bellevue, WA, June 9–13, pp. 104–112. [CrossRef]
Hua, Z.-L., Xing, L.-H., and Gu, L., 2008, “Application of a Modified Quick Scheme to Depth-Averaged κ–ε Turbulence Model Based on Unstructured Grids,” J. Hydrodynam., 20(4), pp. 514–523. [CrossRef]
Tomita, J. T., Silva, L. M. D., and Silva, D. T. D., 2012, “Comparison Between Unstructured and Structured Meshes With Different Turbulence Models for a High Pressure Turbine Application,” Proceedings of ASME Turbo Expo, Copenhagen, Denmark, June 11–15, ASME Paper No. GT2012-69990. [CrossRef]
Rijke, P. L., 1859, “On the Vibration of the Air in a Tube Open at Both Ends,” Philos. Mag., 17, pp. 419–422. [CrossRef]
Patankar, S. V., 1980, Numerical Heat Transfer and Fluid Flow, Hemisphere, New York.
Rhie, C. M., and Chow, W. L., 1982, “A Numerical Study of Turbulent Flow Past an Isolated Airfoil With the Trailing Edge Separation,” AIAA J., 21, pp. 1525–1532. [CrossRef]
Majumdar, S., 1988, “Role of Underrelaxation in Momentum Interpolation for Calculation of Flow With Nonstaggered Grids,” Numer. Heat Transfer, 13(1), pp. 125–132. [CrossRef]
Menter, F. R., 1994, “2-Equation Eddy-Viscosity Turbulence Models for Engineering Applications,” AIAA J., 32(8), pp. 1598–1605. [CrossRef]
Menter, F. R. and Egorov, Y., 2010, “The Scale-Adaptive Simulation Method for Unsteady Turbulent Flow Predictions. Part 1: Theory and Model Description,” Flow Turbul. Combust., 85(1), pp. 113–138. [CrossRef]
Combest, D. P., Ramachandran, P. A., and Dudukovic, M. P.2011, “On the Gradient Diffusion Hypothesis and Passive Scalar Transport in Turbulent Flows,” Ind. Eng. Chem. Res., 50(15), pp. 8817–8823. [CrossRef]
Liu, M., 2012, “Age Distribution in the Kenics Static Micromixer With Convection and Diffusion,” Ind. Eng. Chem. Res., 51(20), pp. 7081–7094. [CrossRef]
Pozarlik, A., 2010, Vibro-Acoustical Instabilities Induced by Combustion Dynamics in Gas Turbine Combustors, University of Twente, Enschede, Netherlands.
Heckl, M., 2010, “The Rijke Tube: A Green's Function Approach in the Frequency Domain,” Acta Acust. Acust., 96(4), pp. 743–752. [CrossRef]
Roman Casado, J. C., and Kok, J. B. W., 2012, “Non-Linear Effects in a Lean Partially Premixed Combustor During Limit Cycle Operation,” Proceeding of ASME Turbo Expo 2012, Copenhagen, Denmark, June 11–15, ASME Paper No. GT2012-69164. [CrossRef]
Altunlu, A. C., Shahi, M., Pozarlik, A. K., van der Hoogt, P. J. M., Kok, J. B. W., and de Boer, A., 2012, “Fluid-Structure Interaction on the Combustion Instability,” 19th International Congress on Sound and Vibration (ICSV19), Vilnius, Lithuania, July 8–12.
Vera, I. H., 2011, “Soot Modeling in Flames and Large-Eddy Simulations of Thermo-Acoustic Instabilities,” Ph.D. thesis, Universite de Toulouse, Toulouse, France.
Ozcan, E., 2012, “Tuning the Self-Excited Thermo-Acoustic Oscillations of a Gas Turbine Combustor to Limit Cycle Operations by Means of Numerical Analysis,” Master's thesis, University of Twente, Enschede, Netherlands.
Rayleigh, J., 1878, “The Explanation of Certain Acoustic Phenomena,” Nature, 18, pp. 319–321. [CrossRef]
Shahi, M., Kok, J. B. W., and Alemela, P. R., 2012, “Simulation of 2-Way Fluid Structure Interaction in a 3D Model Combustor,” Proceedings of ASME Turbo Expo, Copenhagen, Denmark, June 11–15, ASME Paper No. GT2012-69681. [CrossRef]
Ansys, 2010, Release 11.0 Documentation for ANSYS, Ansys Inc., Canonsburg, PA.
Veynante, D., and Vervisch, L., 2002, “Turbulent Combustion Modeling,” Prog. Energy Combust. Sci, 28, pp. 193–266. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

(a) Experimental setup; (b) LIMOUSINE burner

Grahic Jump Location
Fig. 2

A schematic representation of the model combustor: (a) computational domain in CFD calculation; (b) an enlarged view around the wedge; (c) cross-sectional area of the combustor (view from the top)

Grahic Jump Location
Fig. 3

Mesh-dependency studies of structured grid (st) at different locations: (a) y = 10 cm, (b) y = 20 cm, (c) y = 30 cm and unstructured mesh (unst): (d) y = 10 cm, (e) y = 20 cm, (f) y = 30 cm based on the streamwise velocity

Grahic Jump Location
Fig. 4

Comparison of streamwise velocity for the chosen grids taken from cross section A-A at: (a) y = 10 cm, (b) y = 20 cm, (c) y = 30 cm

Grahic Jump Location
Fig. 5

Comparison of streamwise velocity for the chosen grids taken from cross section B-B at: (a) y = 0.5 cm, (b) y = 10 cm, (c) y = 20 cm

Grahic Jump Location
Fig. 6

Comparison of structured (st) (on top) and unstructured mesh (unst) (on bottom) on the mixing behavior of CH4 concentration at: (a) y = 10 cm, (b) y = 20 cm, (c) y = 30 cm

Grahic Jump Location
Fig. 7

Comparison of turbulent eddy viscosity calculated by structured (st) (on top) and unstructured mesh (unst) (on bottom) at (a) y = 10 cm, (b) y = 20 cm, (c) y = 30 cm

Grahic Jump Location
Fig. 8

Streamwise velocity component for 40 kW thermal power and air factor 1.4: experiment (left), structured mesh (middle), unstructured mesh (right)

Grahic Jump Location
Fig. 9

Streamwise velocity component on the cross-sectional area B-B: (a) structured mesh; (b) unstructured mesh

Grahic Jump Location
Fig. 10.

Streamwise velocity component on the cross-sectional area B-B using BVM model power = 60 kW and λ = 1.2

Grahic Jump Location
Fig. 11

Details of mesh around the bluff body for structured mesh

Grahic Jump Location
Fig. 12

Details of mesh around the bluff body for unstructured mesh

Grahic Jump Location
Fig. 13

Numerical residuals using structured (top) and unstructured mesh (bottom)

Grahic Jump Location
Fig. 14

Pressure and temperature monitoring points in the CFD domain: upstream and downstream of the wedge

Grahic Jump Location
Fig. 15

FFT for 40 kW thermal power and air factor 1.4: experiment, structured mesh, unstructured mesh for different locations: (a) p4, (b) p5, (c) p6

Grahic Jump Location
Fig. 16

Pressure (black line) and velocity (gray line) mode shape at the first fundamental frequency (top) and at the third quarter wave mode (bottom) for the structured grid calculations

Grahic Jump Location
Fig. 17

Pressure fluctuations time history (left column) and FFT (right column) at power = 40 kW and λ = 1.4 measured at a location 200 mm downstream of the wedge from experiment ((a) and (b)), BVM ((c) and (d)), Pdf ((e) and (f)), EDM ((g) and (h)), and EDM-FRC ((i) and (j))

Grahic Jump Location
Fig. 18

Stability map of the LIMOUSINE combustor

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In