Time-Domain Analysis of Body Freedom Flutter Based on 6DOF Equation  

作　　者：Zhehan Ji Tongqing Guo Di Zhou Zhiliang Lu Binbin Lyu 

机构地区：[1]Key Laboratory of Unsteady Aerodynamics and Flow Control,Ministry of Industry and Information Technology,Nanjing University of Aeronautics and Astronautics,Nanjing,210016,China [2]High Speed Aerodynamics Institute,China Aerodynamics Research and Development Center,Mianyang,621000,China

出　　处：《Computer Modeling in Engineering & Sciences》2024年第1期489-508,共20页工程与科学中的计算机建模（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(No.11872212)and a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.

摘　　要：The reduced weight and improved efficiency of modern aeronautical structures result in a decreasing separation of frequency ranges of rigid and elastic modes.Particularly,a high-aspect-ratio flexible flying wing is prone to body freedomflutter(BFF),which is a result of coupling of the rigid body short-periodmodewith 1st wing bendingmode.Accurate prediction of the BFF characteristics is helpful to reflect the attitude changes of the vehicle intuitively and design the active flutter suppression control law.Instead of using the rigid body mode,this work simulates the rigid bodymotion of the model by using the six-degree-of-freedom(6DOF)equation.A dynamicmesh generation strategy particularly suitable for BFF simulation of free flying aircraft is developed.An accurate Computational Fluid Dynamics/Computational Structural Dynamics/six-degree-of-freedom equation(CFD/CSD/6DOF)-based BFF prediction method is proposed.Firstly,the time-domain CFD/CSD method is used to calculate the static equilibrium state of the model.Based on this state,the CFD/CSD/6DOF equation is solved in time domain to evaluate the structural response of themodel.Then combinedwith the variable stiffnessmethod,the critical flutter point of the model is obtained.This method is applied to the BFF calculation of a flyingwing model.The calculation results of the BFF characteristics of the model agree well with those fromthe modalmethod andNastran software.Finally,the method is used to analyze the influence factors of BFF.The analysis results show that the flutter speed can be improved by either releasing plunge constraint or moving the center ofmass forward or increasing the pitch inertia.

关 键 词：Body freedom flutter time-domain CFD/CSD/6DOF method dynamic mesh generation strategy aeroelasticity 

分 类 号：V21[航空宇航科学与技术—航空宇航推进理论与工程]