气口参数对环形串联直缸发动机缸内压力的影响

Influences of Gas Port Parameters on In-cylinder Pressures of Annular Connecting Straight Cylinder Engines

针对新构型环形串联直缸发动机介绍了一种基于气道复用的动态位置配气系统。结合双转子气缸差速旋转特性,建立了动态位置配气结构的数学模型及环形串联直缸发动机工作过程的热力学模型,分析了配气系统不同结构参数(气口位置角、尺寸和形状)对环形串联直缸发动机缸内压力变化的影响。采用数值计算方法求解热力学方程组,结果表明,中央配气轴进排气口位置角对缸内压力变化的影响较大,而对气口尺寸的影响较小,旋转配气阀气口尺寸对缸内压力变化的影响较大,而对气口形状的影响较小。发动机高压气动实验结果表明,当中央配气轴进气口位置角为78°、排气口位置角为30°、进气口尺寸为10 mm、排气口尺寸为14 mm、旋转配气阀气道口直径为6 mm时,发动机能够处于正确配气状态并稳定工作。

A dynamic position gas distribution system was introduced based on airway reuse for an innovative ACSCE.Combined with the differential rotation characteristics of dual rotor cylinders,a mathematical model of the dynamic position gas distribution structure and a thermodynamic model of the working processes of ACSCEs were established,and the influences of different structural parameters of the gas distribution system,including the position angle,size and shape,on in-cylinder pressures of ACSCEs were analyzed.The numerical calculation method was used to solve the thermodynamic equations,and the results show that the position angle of the intake and exhaust ports of the central valve shaft(CVS)has a greater impact on in-cylinder pressures,while the port size of CVS has a relatively small effect,and the port size of the rotary valve(RV)also has a great impact on in-cylinder pressures,while the port shape has less effect.The results of high-pressure pneumatic experiments on the engine indicate that when the intake port position angle is as 78°,the exhaust port position angle is as 30°,the intake port size is as 10 mm,the exhaust port size of CVS is as 14 mm and the port size of RV is as 6 mm,the ACSCE may be in correct gas distribution state and work stably.