一体化小涡扇发动机系统的气动热力数值模拟

Aerothermodynamic numerical simulation of integrated small turbofan engine system

关键词:  涡轮风扇发动机  涡轮叶栅  压气机部件  粘性流  气动热力学  一体化设计  数值仿真

Key words:  Turbofan engine  Turbine cascade  Compressor part  Viscous flow  Aerothermodynamics  Integrated design  Numerical simulation

摘要:

建立了一体化弹用小涡扇发动机系统含粘性力项的准三维欧拉流动模型。燃烧室中给出了燃油相对浓度系数和燃烧不完全程度系数经验分布 ;用代数和椭圆形偏微分方程混合方法分别生成叶栅通道和燃烧室内贴体坐标网格 ;分别针对压气机转子、静子和涡轮叶栅 ,定义了三种不同损失系数 ;采用高阶精度 Godunov格式和时间推进法 ,交替使用显 /隐格式 ,收敛速度快 ,计算准确度高。预测了巡航条件下发动机节流特性、内涵喷口几何面积对发动机性能影响 ,结果与其它有效数据相吻合。数值试验表明 ,建立的程序可以预测发动机其他稳态条件下各种特性。经过推广可应用于过渡态的模拟 ,奠定了准三维数值试验台建设的基础

Abstract:

A quasi three dimensional flow Euler model with viscous force terms was constructed for integrated small turbofan engine systems. In the combustor , relative fuel mass chroma coefficient and non full combustion coefficient were suggested empirically.Grids in the flow passage and combustion chamber were generated by employing algebraic and elliptically partial differential equation composite methods.Three viscous losses coefficients in accordance with compressor rotors ,stators and turbine blades were defined separately.Flow calculating from engine inlet to exit were executed using high order Godunov scheme,time matching method and alternatively explicit/implicit schemes. Convergence was fast and the accuracy was satisfactory.The flow control characteristics and the effects of inner duct exit dimension on overall engine performances were presented by the program.The code could forecast the arbitrary steady characteristics of engine systems and be extended to simulations of transient states.