基于循环间变动的排气温度建立了一个发动机循环变动模型 .在这个模型中 ,第n个循环的排气温度作为模型的输入 ,通过定压进气过程、绝热压缩过程、定容燃烧过程、绝热膨胀过程、定容放热过程和定压排气过程来近似汽缸内的热力学过程 ,最后得出第n +1个循环的排气温度 .由于把发动机运行参数 ,如转速、点火角、计量比、进气压力和进气温度等加入该模型 ,可定量地估计这些参数对发动机循环变动的影响 .因为循环间排气温度的波动反映了循环变动程度 ,对排气温度影响最敏感的参数最可能被用于循环变动控制 .模型仿真结果表明 ,对于接近化学计量比的混合气 ,循环变动不明显 ,对于稀薄混合气 ,在部分负荷和较大点火角的情况下 ,循环变动以混沌或分岔的形式出现 A model of engine cycle variation is established based on the exhaust temperature fluctuating between cycles. In this model, the exhaust temperature of the nth cycle is taken as the input of the model. Through the process of constant pressure intake, adiabatic compression and constant volume combustion, Adiabatic expansion process, constant volume exothermic process and constant pressure exhaust process to approximate the thermodynamic process within the cylinder, and finally reached the n +1 +1 cycle of the exhaust temperature.Because the engine operating parameters, such as speed, ignition angle, measurement Ratio, intake pressure and intake air temperature are added to the model to quantitatively estimate the effect of these parameters on engine cycle variation, because fluctuations in the exhaust temperature between cycles reflect the extent of cyclic fluctuations and the parameters that are most sensitive to the exhaust temperature Which is most likely to be used in the control of cyclic variation.The simulation results show that for the near stoichiometric mixture, the cyclic variation is insignificant. For the lean mixture, under the partial load and large ignition angle, Bifurcated form appears