针对高空长航时无人机的动力性和安全性要求,首先应用MATLAB/Simulink对某型一级航空活塞发动机涡轮增压系统建立联合仿真模型.模型主要分为四部分:涡轮增压器模型、发动机平均值模型、中冷器模型和废气阀模型,并根据实验数据对仿真结果进行了校核,确保模型的可行性.在此基础上从整个系统的角度出发研究活塞发动机涡轮增压系统的安全边界,通过发动机级的安全边界要求给出增压器级的安全要求,同时分析主要参数对系统安全性的影响.最后,建立基于安全边界的废气阀的调节规律,使整个活塞发动机涡轮增压系统运行在安全边界之内.结果表明:基于模型的活塞发动机涡轮增压系统的安全边界研究方法给可以给出系统安全运行边界,同时可以在保证安全的前提下为下一步改善发动机涡轮增压系统的性能提供依据,进一步在设计阶段确保系统的安全性.
Aiming to safety and power requirements for unmanned aerial vehicle(UAV) during high altitude long endurance,a simulation model was initially established for a certain aircraft piston turbocharger engine through using the MATLAB/Simulink.The model was constituted by four parts:turbocharger model,mean value engine model,intercooler model and waste gate model.The feasibility of model was verified by empirical data.Then,according to analysis safety margin of turbocharger engine level,the safety requirement for turbocharger engine was proposed,and the impact of key parameters on system safety have been researched.Finally,based on safety margins principles for waste gate was demonstrated,which made the whole turbocharger system of aircraft piston engine performed within the safety margins.The result indicates that the model-based research on turbocharger engine system can obtain safety margin of system,provide reference for further improvement of turbocharger engine system at an acceptable safety level,and ensure the safety requirement during design period.