A Laboratory Investigation into the Fuel Atomization Process in a Diesel Engine for Different Configurations of the Injector Nozzles and Flow Conditions

This paper reports a laboratory investigation of the fuel injection process in a diesel engine.The atomization process of the considered fuel(a hydrocarbon liquid)and the ensuing mixing with air is studied experimentally under high-pressure conditions.Different types of injector nozzles are examined,including(two)new configurations,which are compared in terms of performances to a standard injector manufactured by the Bosch company.For the two alternate configurations,the intake edges of one atomizing hole(hole No.1)are located in the sack volume while for the other(hole No.2)they are located on the locking cone of the needle valve.The injection process,the fuel atomization fineness and fuel supply speed characteristics are studied as functions of high-pressure fuel pump camshaft speed and rotation angle.The results obtained show that a decrease in the high-pressure fuel pump camshaft speed can produce fuel redistribution depending on the injector operation.In general,however,the hole No.1 can ensure fuel flow with higher speed with respect to the hole No.2 for all the operation modes of the injector.Based on such an analysis,we conclude that the use of certain injectors can enable a fine tuning of the propagation process of fuel sprays into various areas of the diesel engine combustion chamber.

引射喷嘴流量系数的计算方法

Based on flow analysis of jet exhausting atomization nozzle,a simplification model and calculating method are put forward to determine flow rate coefficient for jet exhausting atomization nozzle.The method considers the structure of nozzle,properties of fluid and flow state,it overcomes the shortcomings of selecting experimential values.The calculation agrees with the experiment results basically,and calculating errors are all under 3 percent.Therefore the method has wide application.

喷嘴流量特性对直接空冷机组喷雾增湿系统冷却效果影响的数值研究

为研究雾化喷嘴的流量特性对喷雾增湿系统冷却效果的影响,对喷嘴采购提供参考,以计算流体力学理论为基础,建立了某600MW直接空冷单元数值计算模型,采用离散相模型对液滴轨迹进行跟踪,以"有效水份额"来衡量喷雾增湿系统的冷却效果,并确立了汽轮机排汽压力计算方法。结合喷嘴在空冷单元内的布置位置,以普通工业实心锥形喷嘴为对象,分别研究了雾化压力、雾化角、流量系数及喷嘴孔径对冷却效果的影响,结果发现雾化压力、流量系数和雾化角对冷却效果有很大的影响,而喷嘴孔径对冷却效果的影响却不大。

WDH型气泡雾化喷嘴的流量特性研究

ＷＤＨ型气泡雾化柴油、重油、渣油及奥里油燃烧器已在各行业的工业炉窑上得到了广泛的应用。本文对ＷＤＨ型气泡雾化喷嘴的流量特性进行了实验研究。此项研究结果对进一步开发ＷＤＨ型气泡雾化喷嘴的应用领域将发挥重要的作用。

引射雾化喷嘴性能研究

对新型引射雾化喷嘴的流量系数、雾化角、雾粒分布均匀性进行了研究,提出了喷嘴流量系数、雾化角、雾粒大小计算方法。研究表明,这些方法的计算结果与实际很接近,对新型引射雾化喷嘴的设计计算十分有益,具有重要的工程意义。

旋流雾化喷嘴雾化特性的数值模拟

为了掌握旋流雾化喷嘴的雾化特性,基于CFD软件建立了该喷嘴的几何模型进行数值模拟,在验证了网格无关性和数值模拟结果可靠性之后,通过VOF和Realizablek-ε模型对不同压差工作条件下和不同结构的喷嘴分别进行数值模拟。结果表明:旋流雾化喷嘴的雾化流量、雾化锥角和流量系数会随着进、出口压差的增大而增大;喷嘴的旋流强度会随着喷嘴进、出口压差的增大而减小;当喷嘴的出口直径和出口长度增大时,喷嘴的各项雾化参数与理论值更接近,相应的雾化效果变好。

WDH型气泡雾化油枪的流量特性研究

WDH型气泡雾化柴油、重油、渣油及奥里油燃烧器已在各行业的工业炉窑上得到广泛的应用。本文对WDH型气泡雾化喷嘴的流量特性进行了实验研究，此项研究结果对进一步开发WDH型气汇雾化喷嘴的应用领域将发挥重要的作用。

WDH型气泡雾化喷嘴的流量特性研究

WDH型气泡雾化柴油、重油、渣油及奥里油燃烧器已在各行业的工业炉窑上得到了广泛的应用。本文对WDH型气泡雾化喷嘴的流量特性进行了实验研究，此项研究结果对进一步开发WDH型气泡雾化喷嘴的应用领域将发挥重要的作用。

煤矿雾化喷嘴内气液两相流动的CFD数值模拟

应用FLUENT软件,对2种不同K系数的雾化喷嘴进行了数值模拟计算。分析了不同入口压力方案,得出如下结论:相对于K=0的喷嘴,K=0.3的喷嘴可有效地抑制喷嘴口气穴的形成,提高了喷嘴流量的均匀性,更好地实现了流体的有效雾化。