The influence of cavitation on the internal flow and the spray characteristics in diesel injection nozzles
The influence of cavitation on the internal flow and the spray characteristics in diesel injection nozzles
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DOI：
10.1016/j.fuel.2003.09.010
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发表时间：
2004-03-01
期刊：
影响因子：
7.4
通讯作者：
Salvador, FJ
中科院分区：
文献类型：
--
作者：
Payri, F;Bermúdez, V;Salvador, FJ
本文研究了柴油机喷油嘴内空化对内部流动和喷雾宏观特性的影响。在这项研究中，使用了两个双孔喷嘴，一个是圆柱形的，另一个是收敛的（圆锥形的）。从空化的角度来看，所选的两个喷嘴非常不同，因为第一个喷嘴更倾向于空化，而第二个喷嘴抑制空化现象。首先，为了找到两个喷嘴的精确内部几何形状，使用了一种非破坏性的表征方法，该方法基于硅树脂模具的创建。一旦喷嘴在尺寸上被表征，则进行液压表征。该水力特性的结果与预定的尺寸特性一起能够确定流量系数和临界空化条件。通过确定临界空化条件，可以完成有无空化条件下喷雾宏观参数的研究，从而可以研究空化对喷雾宏观行为的影响，从喷雾宏观行为的角度，本文的主要结论是空化导致喷雾锥角的增大。另一方面，从内部流动的角度来看，孔出口速度增加时，空化出现。这种现象可以通过孔的出口部分中的液相的横截面的减小来解释。(C)2004爱思唯尔有限公司保留所有权利。
A study was carried out on the influence of cavitation on the internal flow and the macroscopic behaviour of the spray in Diesel injection nozzles. For this study, two bi-orifice nozzles were used, one cylindrical, and the other convergent (conical). From the point of view of cavitation, the two chosen nozzles are very different, as the first nozzle is much more inclined to cavitate, whereas the second nozzle inhibits the cavitation phenomenon.First, in order to find the exact internal geometry of the two nozzles, a non-destructive characterisation method is used, which is based on the creation of silicone moulds. Once the nozzles are characterised dimensionally, a hydraulic characterisation is made. The results of this hydraulic characterisation, together with the predetermined dimensional characterisation, enable the discharge coefficient and the critical cavitation conditions to be determined. By identifying the critical cavitation conditions, it is possible to complete a study of the macroscopic parameters of the spray, with cavitating and non-cavitating conditions, and therefore a study can be carried out examining the influence of cavitation on the macroscopic spray behaviour.From the point of view of the spray macroscopic behaviour, the main conclusion of the paper is that cavitation leads to an increment of the spray cone angle. On the other hand, from the point of view of the internal flow, the hole outlet velocity increases when cavitation appears. This phenomenon can be explained by the reduction in the cross section of the liquid phase in the outlet section of the hole. (C) 2004 Elsevier Ltd. All rights reserved.