基于CFD/CSD耦合的TEF旋翼气弹特性高精度模拟  

High-precision simulation of aeroelastic characteristics of TEF rotor based on CFD/CSD coupling

作　　者：王华龙 张夏阳 赵国庆[1] 招启军[1] 马砾 WANG Hualong;ZHANG Xiayang;ZHAO Guoqing;ZHAO Qijun;MA Li(National Key Laboratory of Helicopter Aeromechanics,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)

机构地区：[1]南京航空航天大学直升机动力学全国重点实验室,南京210016

出　　处：《航空学报》2024年第18期147-162,共16页Acta Aeronautica et Astronautica Sinica

基　　金：国家重点实验室基金(61422202201);国家自然科学基金(12102186,12032012);中国科协青年人才托举工程(2022QNRC001)。

摘　　要：为分析前飞状态带有后缘小翼的旋翼的气弹特性,建立了一套基于计算流体力学/计算结构动力学(CFD/CSD)耦合的高精度分析方法。基于参数化建模发展了一套含动态后缘小翼的旋翼运动嵌套网格方法。在气动分析方面,在传统气动模型的基础上引入高精度CFD方法,可以精确模拟旋翼非定常流场和气动特性。在结构方面,建立了刚性后缘小翼动力学模型,以附加质量、阻尼、刚度等矩阵的形式考虑刚性后缘小翼运动对旋翼系统的影响,基于Hamilton原理和Timoshenko梁模型建立了系统的非线性动力学方程。采用基于代数变换的弹性网格变形方法,在此基础上发展流固非定常耦合策略。通过对比模型旋翼和SA349/2旋翼气弹响应的计算结果,验证了CFD/CSD耦合方法的有效性。以带后缘小翼的SMART旋翼为算例,与桨叶剖面等效法向力系数的计算结果进行了对比;着重开展Fulton模型旋翼的计算分析,分别研究悬停状态下桨根扭矩和前飞状态下挥舞弯矩幅值的变化规律,并与文献结果进行对比。结果表明:所建立的CFD/CSD耦合方法可以提高旋翼非定常气弹载荷的分析精度,精确捕捉低速前飞旋翼的桨-涡干扰(BVI)现象,挥舞弯矩平均误差可控制在11.68%;同时计算得到的带后缘小翼的桨叶固有频率误差不超过4.0%,桨根挥舞弯矩幅值平均误差为15.15%,能够有效模拟后缘小翼的气弹特性。在单一后缘小翼操纵规律下,Fulton旋翼的桨毂垂向力Fz能够得到有效控制,载荷幅值的降幅可达80%以上。To analyze the aeroelasticity of Trailing Edge Flap(TEF) rotors in forward flight, a high-precision analysis method based on Computational Fluid Dynamics/Computational Structural Dynamics(CFD/CSD) coupling is established. A set of moving-embedded grid method for rotors with TEF is developed by the parametric method. In terms of aerodynamic analysis, the high-precision CFD method, based on the traditional aerodynamic model, is introduced to accurately simulate the unsteady flow field and aerodynamic characteristics of the rotor. In terms of structure, the dynamic model of rigid TEFs is established, the influence of the rigid TEF motion on the rotor system is considered in the form of additional mass, damping, stiffness and other matrices, and the nonlinear dynamic equation of the rotor system is derived based on Hamilton's principle and Timoshenko beam model. An elastic grid deformation method based on algebraic transformation is adopted, and the unsteady fluid-solid coupling strategy is developed. Results comparison of the aeroelastic loads of the model rotor and the SA349/2 rotor verifies the effectiveness of the CFD/CSD coupling method. On this basis, taking the SMART rotor with TEF as an example, the calculation results are compared with the equivalent normal force coefficient of the blade sections. Emphasis is placed on the analysis of the Fulton model rotor, studying the variation of blade root torque in hover and flap moment amplitude in forward flight, and comparing them with literature results. Results show that the proposed CFD/CSD coupling method can improve the analysis accuracy of the unsteady aeroelastic load of the rotor, and accurately capture the Blade-Vortex Interaction(BVI) phenomenon of the low-speed forward flight rotor, with the average error of flap bending moment controlled at 11. 68%. Meanwhile, the natural frequency error of the blade with TEF is smaller than 4. 0%, and the average error of flap bending moment amplitude of the blade root is 15. 15%, meaning that the aeroelastic characteri

关 键 词：旋翼动力学 后缘小翼 气动弹性 CFD/CSD方法 气弹载荷 

分 类 号：V211.52[航空宇航科学与技术—航空宇航推进理论与工程]