Journal of the Combustion Society of Japan
Online ISSN : 2424-1687
Print ISSN : 1347-1864
ISSN-L : 1347-1864
Volume 48 , Issue 144
Showing 1-7 articles out of 7 articles from the selected issue
FEATURE—Formation and Discharge of Particulate Matter
SERIAL LECTURE—Fuel Cells and Combustion Engineering IV
ORIGINAL PAPER
  • Mukundan N. DEEPU, Sadanand. S. GOKHALE, Simon JAYARAJ
    Type: ORIGINAL PAPER
    2006 Volume 48 Issue 144 Pages 187-197
    Published: 2006
    Released: October 24, 2019
    JOURNALS FREE ACCESS

    Numerical simulation of supersonic combustion of hydrogen in air has been done using point implicit finite volume method. This method treats all chemical species terms implicitly and all other terms explicitly. Solver is based on the solution of unsteady, compressible, turbulent Navier-Stokes equations, using Unstructured Finite Volume Method (UFVM) incorporating RNG based κ-ε two equation model and time integration using three stage Runge-Kutta method. Reaction of hydrogen with air is modeled using an eight-step reaction mechanism. The preconditioning has found to be effective in overcoming the stiffness in chemically reacting flows. The method is validated against standard experiments for CFD code validation. The predicted values of temperature and species production were in good agreement with experimental results. The code is used to simulate the combustion of hydrogen injected to the wake region formed by a wedge shaped strut.

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  • Akira YOSHIDA, Hiroyoshi NAITO, Debi P. MISHRA
    Type: ORIGINAL PAPER
    2006 Volume 48 Issue 144 Pages 198-205
    Published: 2006
    Released: October 24, 2019
    JOURNALS FREE ACCESS

    The flame structure at small Damkohler number and large Karlovitz number is still unknown. In the present study, the reaction zone structure in a well-stirred reactor was investigated extensively. The OH-PLIF images suggested that there are no thin laminar flamelets and that the reacting eddies are distributed throughout the reactor. With the cross-correlation of ion signals, the scale of the reacting eddies was determined to be of the order of 4mm, and the convection velocity of these eddies or zones was found to coincide with the mean flow velocity of the order of 100m/s. In this combustion regime, NOx concentration was extremely low and this is very attractive for the practical use to meet the environmental requirements.

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  • Takehiko SEO, Fumiteru AKAMATSU, Masahiko SHIBAHARA, Masashi KATSUKI
    Type: ORIGINAL PAPER
    2006 Volume 48 Issue 144 Pages 206-213
    Published: 2006
    Released: October 24, 2019
    JOURNALS FREE ACCESS

    Combinations of optical interference band-pass filter and photomultiplier are often used for detecting OH* and CH* chemiluminescences in examining the correlation between chemiluminescent intensities and the combustion quantities, such as equivalence ratio and temperature. Since we consider that the influence of continuous background emission on chemiluminescent emission intensities should not be ignored, we propose a technique for removing those influences on OH* and CH* chemiluminescent emission intensities measured by the combination of optical band-pass filters and photomultipliers. Moreover, the correlation between the actual chemiluminescent emission intensities without the influence of continuous background emission and the physical quantities has been investigated in the present study. By separating chemiluminescent emission intensities of OH* and CH* from continuous background emission intensities, it becomes possible to measure equivalence ratio using chemiluminescent emission intensities at any positions of a flame. This technique holds wider applicability than the conventional methods.

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