• Title/Summary/Keyword: clipped Gaussian distribution

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On the Effect of Presumed PDF and Intermittency on the Numerical Simulation of a Diffusion Flame

  • Riechelmann, Dirk;Fujimori, Toshiro
    • Journal of the Korean Society of Combustion
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    • v.6 no.2
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    • pp.23-28
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    • 2001
  • In the present work, the effect of PDF selection and intermittency on the result of the numerical simulation are examined by the simulation of a turbulent methane-air jet diffusion flame. As to the PDFs, beta-function and clipped Gaussian are considered. Results for the pure mixing jet are compared with experimental results. Then, the turbulent flame is calculated for the same conditions and the results obtained for the several models are compared. It is found that the clipped Gaussian distribution coupled with consideration of intermittency recovers the experimental data very well. As to the reacting flow results, the main overall properties of the turbulent jet diffusion flame such as maximum flame temperature are less affected by the choice of the PDF. Flame height and NO emissions, on the contrary, appear to be significantly influenced.

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Analysis of Flows in the Combustor with Recirculating Flow Regime (재순환영역을 가지는 연소기내의 연소유동해석)

  • 신동신;허남건
    • Journal of the Korean Society of Propulsion Engineers
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    • v.1 no.2
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    • pp.22-31
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    • 1997
  • We developed a general purpose program for the analysis of flows in the combustor with recirculating flow regime and simulated the flows. The program uses non-staggered grids based on finite volume method and the primitive variables are cartesian velocities. The combustion model is irreversible one step reaction with infinite chemistry The Favre averaged governing equations are considered and the clipped gaussian distribution is considered as a probability density function of the conserved scalar. We calculated turbulent diffusion flame with recirculating flow regime. Simulation shows two recirculating regions like experimental results. Velocity, turbulent kinetic energy, temperature and concentration distribution in simulation agree well with experimental data.

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