直喷涡轮增压汽油机动态响应特性理想恒速模拟及评价

Simulation and Evaluation for Dynamic Response of A Turbo-Charged GDI Engine under Ideal and Constant Speed Conditions

鉴于在发动机台架上难以实现发动机动态响应特性的直接测评,提出直喷涡轮增压汽油机动态响应特性的理想恒速模拟。基于稳态性能试验,建立发动机热力学模型并将其扩展以适用于瞬变过程模拟;假定平衡发动机动力输出的负载响应时间为零,模拟发动机恒定转速下动力输出随节气门开度的瞬变关系,并在此理想条件下评价发动机的动态响应特性。将该方法运用于评估J、P两型涡轮增压器对1.5T GDI发动机动态响应特性的影响,实现了发动机和增压器的合理匹配。

It is difficult to evaluate the engine dynamic response directly on the engine test bench. To overcome this difficulty, an ideal and constant speed simulation method for the dynamic response of a turbo-charged GDI engine is proposed. Based on the steady- state performance test, a thermodynamic model of the basic engine is established and adjusted for the transient process simulation. The transient relationship between the engine power output and the throttle opening at constant speed is simulated and the dynamic response characteristics of the basic engine is evaluated by assuming that the response time of balancing the engine power output is zero. The method is applied to evaluate the effects of J and P turbochargers on the dynamic response of a 1.5T GDI engine, achieving a logical match between the engine and the turbochargers.