Abstract The paper deals with the issue of determining the geometry of fuel spray generated by the outward-opening type of injectors. The design of the outward-opening type injector is the reason for the initial fuel flow taking a circular shape (an empty cone). With increasing pressure of the injected fuel this geometry changes into a square one. The aim of the research was to determine the conditions of these changes and to propose how to define the geometry in the form of an indicator z (accepting positive values – for circular geometry, and negative values – for square geometry) as well as to generalize the equation zeq making it possible to determine the indicator of the fuel spray geometric structure changes. The defined indicator z shows that fuel injection pressure exceeding 15 MPa plays an important role in changing the geometric structure of the fuel spray. The back pressure of the medium into which the fuel is injected does not affect the determined value of the indicator. Additionally, an indicator of variation of radial penetration of the fuel spray CoV(Sr) and the indicator of linear to radial fuel spray penetration Sl/Sr-av were determined, which only under certain conditions can replace the z indicator.

中文翻译：

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汽油喷射参数对外开式喷油器喷射的燃油喷雾几何结构的影响

摘要 本文研究了确定外开式喷油器产生的燃油喷雾几何形状的问题。外开式喷油器的设计是初始燃油流呈圆形（空锥体）的原因。随着喷射燃料压力的增加，这种几何形状变为方形。研究的目的是确定这些变化的条件，并提出如何以指标 z 的形式定义几何（接受正值 - 对于圆形几何，和负值 - 对于方形几何）以及概括方程 zeq 使得确定燃料喷雾几何结构变化的指标成为可能。定义的指标 z 表明，超过 15 MPa 的燃油喷射压力对改变燃油喷雾的几何结构起着重要作用。注入燃料的介质的背压不影响指标的确定值。此外，确定了燃料喷雾径向穿透变化的指标 CoV(Sr) 和线性到径向燃料喷雾穿透的指标 Sl/Sr-av，只有在某些条件下才能替代 z 指标。