Journal of Mechanical Science and Technology

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지

Effects of a Swirling and Recirculating Flow on the Combustion Characteristics in Non- Premixed Flat Flames

  • Published : 2004.03.01
Download PDF
⟨ Previous Next ⟩

Abstract

The effects of swirl intensity on non-reacting and reacting flow characteristics in a flat flame burner (FFB) with four types of swirlers were investigated. Experiments using the PIV method were conducted for several flow conditions with four swirl numbers of 0, 0.26, 0.6 and 1.24 in non-reacting flow. The results show that the strong swirling flow causes a recirculation, which has the toroidal structures, and spreads above the burner exit plane. Reacting flow characteristics such as temperature and the NO concentrations were also investigated in comparison with non-reacting flow characteristics. The mean flame temperature was measured as the function of radial distance, and the results show that the strong swirl intensity causes the mean temperature distributions to be uniform. However the mean temperature distributions at the swirl number of 0 show the typical distribution of long flames. NO concentration measurements show that the central toroidal recirculation zone caused by the strong swirl intensity results in much greater reduction in NO emissions, compared to the non-swirl condition. For classification into the flame structure interiorly, the turbulence Reynolds number and the Damkohler number have been examined at each condition. The interrelation between reacting and non-reacting flows shows that flame structures with swirl intensity belong to a wrinkled laminar-flame regime.

Keywords

References

  1. Adrian R. J., 1991, 'Particle Imaging Techniques for Experimental Fluid Mechanics.' Annu. Rev. Fluid Mech., Vol. 23, pp. 201-304 https://doi.org/10.1146/annurev.fl.23.010191.001401
  2. Armstrong, N. W. H. and Bray, K. N. C., 1992, 'Premixed Turbulent Combustion Flow-field Measurement Using PIV and LST and Their Application to Flamelet Modeling of Engine Combustion,' SAE, No. 922322
  3. Buckley, P. L., Craig, R. R., Davis, D. L. and Schwartzkopf, K. G., 1983, 'The Design and Combustion Performance of Practical Swirless for Integral Rocket/Ramjets,' AIAA, 21(5), pp. 740-743
  4. Chang, T. P., 1985, 'Image Processing of Tracer Particle Motion as Applied to Mixing and Turbulent Flow,' Chemical Engineering Science, Vol. 40, No. 2
  5. Chaturvedi, M. C., 1963, 'Flow Characteristics of Axisymmetric Expansion,' Proceedings J. of the Hydraulics Division, ASCE, Vol. 89, No. HY3, pp. 61-92
  6. Chiger, N. A. and Yule, A. J., 'The Physical Structure of Turbulent Flame,' AIAA 1979-0217, pp. 1-8
  7. Choi, G. M. and Katsuki, M., 2001, 'Advanced low Nox Combustion Using Highly Preheated Air,' Energy conversion and Management, Vol. 42, pp. 639-652 https://doi.org/10.1016/S0196-8904(00)00074-1
  8. Gupta, A. K., Lilley, D. G. and Syred, N., 1984, Swirl Flows, Abacus Press, Turnbridge wells
  9. Hall, M. G., 1972, 'Vortex Breakdown,' Annual review of Fluid Mechanics 4, pp. 195-218 https://doi.org/10.1146/annurev.fl.04.010172.001211
  10. Hoffmann, S., Lenze, B. and Eickhoff, H., 1998, 'Results of Experiments and Models for Predicting Stability Limits of Turbulent Swirling Flames,' Journal of Engineering for Gas Turbines and Power, Transactions of the ASME, Vol. 120, No. 2, pp. 311-316 https://doi.org/10.1115/1.2818122
  11. Lee, S. G., Song, K. K. and Rho, B. J., 2002, 'Investigation of Turbulent Spray Disintegration Characteristics Depending on the Nozzle Configuration,' KSME (Int.), Vol. 16, No. 4, pp. 572-579
  12. Lee, S. J., 1999, PIV-Velocity Field Measurement, POSTECH
  13. Lee, S. N., Yoon, H. K. and Ryu, J. I., 1996, 'Flow Field Characteristics of a High Load Combustor,' KSME, pp. 58-63
  14. Lefebvre, A. H., 1983, Gas Turbine Combusion, Hemishere, Washington, DC
  15. Mathur, M. L. and Maccallum, N. R. L., 1976, 'Swirling Air Tests Issuing from Vane Swirlers,' J. of the Institute of Fuel, Vol. 41, pp. 238-240
  16. Ralph, A., Dalla, B. and Thomas, R. N., 1999, 'Application of Catalytic Combustion to a 1.5 MW Industrial Gas Turbine,' Catalysis Today, Vol. 47, Issues 1-4, pp. 369-375 https://doi.org/10.1016/S0920-5861(98)00319-8
  17. Ryan, B. W. and John, K. E., 2001, 'Structure of a Swirling, Recircilating Coaxial Free Jet and Its Effect on Particle Motion,' Int. J. Multiphase Flow 27, pp. 949-970 https://doi.org/10.1016/S0301-9322(00)00061-6
  18. Saad, A. A. 1998, 'Velocity Mesurements and Turbulence Statistics of a Confined Isothermal Swirling Flow,' Experimental Thermal and Fluid Science, Vol. 17, pp. 256-264 https://doi.org/10.1016/S0894-1777(97)10039-5
  19. Stephan, E. S. and Paul, O. H., 1995, 'CARS Temperature and LDA Velocity Measurements in a Turbulent, Swirling, Premixed Propane/Air Fueled Model Gas Turbine Combustor,' ASME 95-GT-64
  20. Turns, S. R., 2000, An Introduction to Combustion Concepts and Applications, McGRAW-HILL
  21. Yegian, D. T. and Cheng, R. K., 1998, 'Developement of a Lean Premixed Low-Swirl Burner for Low NOx Practical Applications,' Com. Sci. and Tech., Vol. 139, No. 1, pp. 207-238 https://doi.org/10.1080/00102209808952088