涡扇发动机二元喷管模型吹风对比试验

在多功能热喷流实验台,进行了某型涡扇发动机二元喷管模型试验件与常规轴对称喷管模型试验件吹风对比试验。试验结果表明:与常规轴对称喷管相比,采用二元喷管后,其尾喷流的流场速度快速衰减,其温度比常规轴对称喷管衰减得快得多,射流的高温区沿轴向大幅减少(大约为原来的1/5),这对红外辐射的抑制十分有利。     

超音通流风扇发动机初探

从不同的角度对超音通流风扇发动机进行了探讨，介绍了超音通流风扇（ＳＴＦＦ）的工作模式及超音通流风扇与涡轮喷气发动机（ＳＴＦＦ－ＴＪ）、空气涡轮火箭组合发动机（ＳＴＦＦ－ＡＴＲ）的性能优势，讨论了ＳＴＦＦ发动机与飞机的一体化问题，分析了影响安装阻力的主要因素。指出ＳＴＦＦ发动机比传统的涡轮风扇发动机（ＴＢＥ）的摩擦阻力系数低，升阻比高，说明这是一种有巨大潜力的新型发动机。     

涡扇发动机转速鲁棒控制器设计及试验

在分析某型涡扇发动机试验数据的基础上，给出了涡扇发动机在不同转速下频率特性的变化，得到了涡扇发动机数学模型参数摄动的权函数，设计了一个满足给定鲁棒性能指标的控制器。通过试验验证了涡扇发动机控制系统的鲁棒性能。     

变几何涡扇发动机加速控制规律优化设计

首先建立了一种变几何通道涡扇发动机数学模型,该模型中,风扇及压气机在不同进口导流叶片角度下的特性是通过对基准特性的修正而获得的。然后根据变几何涡扇发动机的特点,利用非线性规划中的约束变尺度法（ＣＶＭ）设计了最优加速规律。研究结果表明：用约束变尺度法优化设计出的发动机加速控制规律,可以保证发动机在全飞行包线范围内稳定工作,且加速时间最短。     

Limit protection design in turbofan engine acceleration control based on scheduling command governor

A new limit protection method based on Scheduling Command Governor (SCG) is proposed for imposing multiple constraints on a turbofan engine during acceleration process. A Gain Scheduling Controller (GSC) is designed for the transient state control and its stability proof is developed using Linear Matrix Inequalities (LMIs). The SCG is an add-on control scheme which manages engine limits effectively based on reference trajectory optimization. Unlike the traditional min–max architecture with switching logic, the SCG method utilizes the Linear Parameter Varying (LPV) closed-loop model to form a prediction of future constraint violation and per instant solves a constraint-admissible reference within an approximate Maximal Output Admissible Set (MOAS). The influence of the variation of engine dynamic characteristics and equilibrium points during transient state control is handled by the design of contractive sets. Simulation results on a turbofan engine component-level model show the applicability and effectiveness of the SCG method. Compared to the traditional min–max method, the SCG method has less conservativeness. In addition, the design of contractive sets makes conservativeness tunable.     

蚌壳式反推装置打开时反推性能参数计算

根据自由流线理论建立了蚌壳式反推装置二维流动数学模型,得到蚌壳式反推装置打开时反向气流偏转角 与蚌壳式反推装置几何参数间的关联关系。将该模型和涡扇发动机性能计算模型耦合,得到了蚌壳式反推装置打开时反推参数的计算模型。以某型涡扇发动机为例,计算了着陆时反推气流角和反推装置几何参数,以及反推力随马赫数、发动机转速的变化关系,并与测量数据进行了对比分析。表明本文给出的蚌壳式反推装置打开时反推性能计算模型具有较好的计算精度。     

高空长航时无人机用涡扇发动机技术分析

为了研制能在高空稳定工作、且耗油率低的、高空长航时用的涡扇发动机,借助数值计算和试验数据,对此类发动机在高空工作时,其压缩系统、燃烧系统、涡轮、控制系统、润滑系统和内部空气系统所遇到的问题作了较为系统、深入的探讨和分析。结果表明,高空低Re使压缩系统、燃烧系统和涡轮性能下降,控制系统必须调整所有与飞行高度有关的参数,滑油箱压力、油泵气蚀和滑油冷却问题必须予以考虑,内部空气系统会影响冷却和封严效果。对每一个问题都提出了相应的解决办法。     

Simulation of the secondary air system of turbofan engines: Insights from 1D-3D modeling

Focusing on the internal flow and heat transfer analysis, a platform for the performance evaluation of the Secondary Air System (SAS) is developed. A multi-fidelity modeling technique has been developed in a turbofan engine model under different flight conditions. A turbine blade cooling model which integrates external heat transfer calculations and coolant side modeling with common components is proposed. In addition, the Computational Fluid Dynamics (CFD) method is selected to capture the complex flow field structure in the preswirl system. The validity of the SAS models is compared with publicly available data. An elaborately designed cooling system for the AGTF30 engine is analyzed through three main branches. It is found that the 1D-3D modeling technique can provide more accurate predictions of the SAS for the AGTF30 engine. The results demonstrate the versatility and flexibility of the SAS models, thereby indicating the capacity of meeting most of the demands of flow and thermal analysis of the SAS.