【摘 要】
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Effect of the ambient O2 concentration and the injection duration on the spray combustion characteristics of diesel fuel was experimentally examined in this study.The detailed combustion characteristi
【机 构】
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Department of Mechanical Engineering,Tokai University,Japan
【出 处】
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13th International Conference on Liquid Atomization and Spra
论文部分内容阅读
Effect of the ambient O2 concentration and the injection duration on the spray combustion characteristics of diesel fuel was experimentally examined in this study.The detailed combustion characteristics were evaluated using a high-temperature,high-pressure combustion vessel.Ambient high-pressure and high-temperature conditions in the vessel were achieved by the combustion of hydrogen in an enriched-oxygen air mixture.The sequential images were obtained by using a high-speed color video camera and were analyzed using the two color method to quantify soot temperature and KL factor.The temperature and pressure within the combustion vessel at the injection timing as well as the fuel injection pressure were held at constant values of 985 K,3 MPa and 100 MPa respectively.The O2 concentration was changed from 21%to 9%and the injection duration was varied from 0.4 ms to 1.2 ms.Based on a series of systematic experiments,we confirmed that O2 concentration is a dominant factor affecting the ignition delay and the flame temperature.As the decrease in O2 concentrations,the ignition delay was elongated and the flame temperature was decreased,while the change of the injection duration has a slight effect on the ignition delay and the temporal variation of the flame temperature.On the contrary not only the O2 concentration but also the injection duration have a large effect on the soot distribution in flame.It is found that the soot distribution was subdivided in two regions,i.e.,the soot cloud at the flame tip region and the quasi-steady flame tail region.The injection duration has a large effect on the temporal variation of the soot distribution in the quasi-steady region while the soot cloud at the flame tip was almost constant under the injection duration examined in this study.
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