船用柴油机进气道类型及结构参数对流通性能的影响

The influence of intake ports type and geometric parameters on flow field characteristics of marine diesel engine

以船用柴油机进气道为研究对象,用经试验验证的数值模拟方法研究了不同类型进气道的流通特性及串联进气道主要结构参数对气道流通性能的影响。研究结果表明,不同类型气道中,并联气道进气能力较串联气道要大,但并联气道形成的涡流比很弱;串联气道流量系数比对称型并联气道稍小,但能形成一定的涡流比;在进气道喉口面积一定的情况下,气道进口面积大小是影响气道流量系数最明显的结构参数,其余结构参数对气道流量系数影响都很小;进气道各结构参数对气道涡流比都有影响,其中气阀座高对涡流比影响最大,气道进口高度对涡流比影响也比较明显;气道出口处气流分布情况影响进气涡流大小,沿缸套周向速度分量越大,形成进气涡流的能力越大。

In this paper,the intake ports of marine diesel engine are studied.The validated numerical simulation method is used to research the flow characteristics of different types of intake ports and the influences of series-wound intake ports structural parameters on their flow characteristics.The results show that：in different types of intake ports,the shunt-wound intake ports＇ ability of air charge is larger than series-wound intake ports,but the swirl ratio it generated is weak;the flow ratio of the series-wound intake ports is smaller than the symmetrical shunt-wound intake ports,but it can generate a certain degree of swril ratio;as the intake ports＇ throat area is fixed,the intake ports＇ inlet area is the most obvious structural factor that influence the intake ports flow ratio,other fators have little influence;all the structural factors have influence on swril ratio,among which the height of the valve seat influence most obviously,the height of the intake ports＇ inlet also has obvious influence;the intake ports outlet＇s airflow velocity distribution influence the magnitude of swril ratio,the higher the circumferential velocity component is,the larger the swril ratio can be.