点火位置对X型转子发动机燃烧过程的影响  

Effects of Ignition Positions on the Combustion Process of an X-Type Rotary Engine

作　　者：邹润[1] 杨伟[1] 张磊[1] 苏铁熊[1] 张翼[1] 李良钰 ZOU Run;YANG Wei;ZHANG Lei;SU Tiexiong;ZHANG Yi;LI Liangyu(School of Energy and Power Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学能源与动力工程学院,太原030051

出　　处：《内燃机工程》2024年第3期50-58,69,共10页Chinese Internal Combustion Engine Engineering

基　　金：山西省基础研究计划项目(202203021222045)。

摘　　要：为探究X型转子发动机独特燃烧室内复杂湍流场与点火位置的耦合作用对混合气燃烧过程的影响,建立了X型转子发动机的三维计算流体动力学模型,并与试验结果进行对比验证,数值研究了不同点火位置下X型转子发动机缸内燃烧过程,揭示了点火位置对火焰传播、燃烧特性及污染物形成的影响规律。结果表明,在压缩末期,X型转子发动机燃烧室内形成了包括涡流和单向流的复杂湍流场,这与点火位置的耦合作用显著影响火焰传播过程。为了获得较高火焰传播速度,点火位置不宜布置在漩涡区处。点火位置位于凹坑中部时,可以充分利用四周空间和涡团与单向流场过渡处形成的较高速度场加速火焰传播,从而提前燃烧重心,增加放热速率,而且峰值压力提高了25%,指示热效率超过30%;同时其也具有较低的HC和CO排放量;但是由于其缸内峰值温度较大,导致NO排放量增加。In order to investigate the influences of coupling effect of the complex turbulent field and ignition positions in the unique combustion chamber of an X-type rotary engine on the mixture combustion process,a three-dimensional CFD model of the X-type rotary engine was established and validated with the test results.The in-cylinder combustion process of the X-type rotary engine under different ignition positions was numerically investigated,revealing the influences of ignition positions on the flame propagation,combustion characteristics and pollutant formation.Results show that at the late stage of compression stroke,the complex turbulence fields including vortex and unidirectional flow are formed in the combustion chamber of the X-type rotary engine,which significantly affects the flame propagation process by the coupling effect with the ignition position.In order to obtain the high flame propagation speed,the ignition position is not suitable to be located at the vortex region.When the ignition position is located in the middle of the recess,the flame propagation can be accelerated by taking full advantage of the surrounding space and the higher velocity field formed at the transition between the vortex mass and the unidirectional flow field,thus advancing the center of gravity of combustion and increasing the rate of heat release.And the peak pressure is increased by 25%,with an indicated thermal efficiency of more than 30%and low emissions of HC and CO.However,due to the larger peak in-cylinder temperature,it leads to an increase in NO emissions.

关 键 词：X型转子发动机 点火位置 计算流体动力学 仿真 燃烧过程 排放 

分 类 号：TK45[动力工程及工程热物理—动力机械及工程]