基于定容燃烧弹的单孔主动预燃室几何参数对燃烧特性的影响研究

Effect of Geometrical Parameters on Combustion Characteristics for Single-Orifice Active Pre-Chamber Based on Volume Constant Combustion Vessel

基于定容燃烧弹试验平台,采用燃烧可视化方法研究了预混式单孔主动预燃室的几何参数对预燃室点火特性的影响。在火焰发展初期的定压燃烧过程中,将从点火开始到火焰面积达到燃烧弹可视窗口面积一半所用的时间定义为初期火焰发展时间,作为衡量不同几何参数下主动预燃室点火效果的参考指标:在不同喷孔孔径(2.0~4.0 mm)、不同预燃室通道内径(3.0~5.5 mm)、不同下端开口角度(0°~75°)的试验条件下,初期火焰发展时间的最大差异分别为9.3 ms、6.8 ms、2.9 ms,最终得出3个几何参数对单孔主动预燃室点火效果的影响程度排序由大到小依次为喷孔孔径、预燃室通道内径、下端开口角度。

Based on the test platform of volume constant combustion bomb,the influence of geometrical parameters of the premixed single-orifice active pre-chamber on the ignition characteristics of the pre-chamber were investigated by the combustion visualization method.During the pressure constant combustion process in the early stage of flame development,the time from the start of ignition until the flame area reaches half of the visible window area of the combustion vessel is defined as the initial flame development time,which is used as a reference index to measure the ignition effect of the active pre-chamber under different geometrical parameters:under the test conditions of different orifice diameters(2.0~4.0 mm),different inner diameters of the pre-chamber channel(3.0~5.5 mm),and different open angles of the lower end(0°~75°),the maximal differences of initial flame development time are 9.3 ms,6.8 ms,and 2.9 ms,respectively.Therefore,the effect of the three geometrical parameters on the ignition effect of the single-orifice active pre-chamber are,in descending order,the orifice diameter,the inner diameter of the pre-chamber channel and the opening angle of the lower end of the pre-chamber.