Combustion Analysis of Unsteady Diffusion Flame of Spray by Means of Measurement of Spatial Distribution of Chemical Species and Soot

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The outline of research results conducted during the term of this project is as follows :1)Modeling of unsteady and evaporating spray impinging on a flat and hot wallThe evaporating process of an unsteady spray impinging on a flat and hot wall is simulated precisely by use of new three models, that is, droplet breakup model, droplet dispersion model and heat transfer model, as the significant step of the simulation of its flame. They can express all the evaporation phenomena of non-boiling, nucleate, transition and filmboilings. The objective spray is simulated by KIVA-II original code applying these models. The simulated results of distributions of fuel vapor concentration and droplet parcels agree very well the experimental results detected by the laser induced method.2)Combustion analysis of unsteady diffusion flame of spray in direct injection diesel engine with optical accessThe simultaneous application of methods of laser induced scattering and laser induced incandescence, that o … More f two-color method and the measurement of the natural emission of OH radicalas the representative of chemical species were carried out in the objective flame generating in a direct injection diesel engine with the optical access to detect distributions of soot, OH radical and flame temperature. The following main conclusions are drawn :(1)The mean relative soot diameter increases as the passage of the time during the period of diffusion burning.(2) The mean relative soot number density has the peak when combustion turns from the pre-mixed burning to the diffusion burning.(3)In the central region of the combustion chamber a great deal of soots with small diameter produce by the pre-mixed burning.(4)The first appearance of the natural emission of OHI radical is later than that of soot.3)Combustion analysis of unsteady diffusion flame of spray in in-direct injection diesel engine with optical accessThe distribution of the natural emission of OH radical and those of soot and flame temperature by means of the two-color method were measured in the obj ective flame. The following main conclusions are obtained :(1)The counter clock wise flow appears in the swirl chamber during the initial combustion stage.(2)The flame temperature is low near the passage way between both swirl and main chambers during the middle combustion stage.(3)The natural emission of OH radical breaks out near the passage way and the flame tip region. Less