柔性飞行器在气动力作用下会发生大变形,产生结构几何非线性,线性小变形方法难以获得准确的气动弹性分析结果。基于RANs的三维N-S流场控制方程耦合非线性结构静力学方程时域分析方法,用于考虑结构几何非线性的静气动弹性分析。该方法在结构静力学方程求解上采用非线性增量有限元方法进行迭代求解,考虑结构刚度矩阵随结构位形的变化,采用径向基函数方法实现气动/结构界面的数据交换和动网格变形。在建立某型宽体客机复材机翼三维有限元模型的基础上,对其静气动弹性进行了数值仿真,分析了线性结构和考虑结构几何非线性的结构在静气动弹性作用下翼面扭转、展向位移、垂向位移以及升力系数等物理量。算例结果表明,与线性结果相比,非线性结构由于结构几何非线性的影响,在展向和垂向变形上两者存在显著差异。为准确进行柔性结构的气动弹性分析,必须考虑结构几何非线性的影响。
Abstract
Flexible aircrafts tend to undergo large deformation under aerodynamic forces, as a result, structural geometric nonlinearity occurs. The linear small deformation theory cannot give accurate results for analysis of static aeroelasticity. Fluid structure coupling method based on three dimensional RANs Navier-Stokes equations and nonlinear static equation is used for static aeroelastic analysis with structural geometric nonlinearity. The mentioned approach adopts nonlinear incremental finite element method to solve nonlinear static equation with assembled structure stiffness matrix. Moreover, RBF method is used for data interpolation and mesh deformation. Based on multi-material wing finite element model, the numerical simulations were made to analyse the static aeroelastic behavior. The comparisons of twist angles, vertical displacements, spanwise displacements and life coefficients between linear and nonlinear structure were made. The results show that geometric nonlinearity cannot be neglected for predicting accurate static aeroelastic behavior for large flexible airplanes.
关键词
静气动弹性 /
结构几何非线性 /
柔性飞行器
{{custom_keyword}} /
Key words
static aeroelastic analysis /
geometric nonlinearity /
flexible aircrafts
{{custom_keyword}} /
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] Patil MJ, Hodges DH. Limit cycle oscillations in high-aspect-ratio Wings. AIAA-99-1464,1999.
[2] Patil MJ, Hodges DH. On the importance of aerodynamic and structural nonlinearities in aeroelastic behavior of high -aspect-ratio wings. AIAA 2000-1448, 2000.
[3] Patil MJ, Hodges DH, Cesnik C. Characterizing the effects of geometrical nonlinearities on aeroelastic behavior of high-aspect-ratio wings. International Forum on Aeroelasticity and Structural Dynamics. 22 June -25 June 1999,Williamsburg, USA.
[4] 杨智春, 张惠,谷迎松等.考虑几何非线性效应的大展弦比机翼气动弹性分析[J].振动与冲击,2014,33(16):72-75. Yang Zhi-chun, Zhang Hui, Gu Ying-song, et al. Aeroelastic analysis of the high aspect ratio wing considering the geometric nonlinearity[J]. Vibration and Shock, 2014,33(16):72-75.
[5] Simth M J, Patil M J and Hodges D H. CFD-based analysis of nonlinear aeroelastic behavior of high-aspect ratio wing [C]. AIAA 2001-1582,2001.
[6] Garcia J A,Guruswamy G P. Aeroelastic analysis of transonic wings using Navier-Stokes equations and a nonlinear beam finite element model[C]. AIAA 1999-1215,1999.
[7] Palacios R and Cesnik CES. Static nonlinear aeroelasticity of flexible slender wings in compressible flow[C]. AIAA 2005-1945,2005
[8] Roe PL. Approximate Riemann solvers, parameter vectors, and difference schemes. Journal of Computational Physics,43,357-372,1981.
[9] 王勖成.有限单元法[M].北京:清华大学出版社,2002.
Wang Xu-cheng. Finite Element Method[M]. Beijing: Tsinghua University Press, 2002.
[10] 张伟伟,高传强,叶正寅. 气动弹性计算中网格变形方法研究进展. 航空学报. 2014(35):303-319.
Zhang Wei-wei,Gao Chuan-qiang,Ye Zheng-yin. Research progress on mesh deformation method in computational aeroelasticity. Acta Aeronautica et Astronautica Sinica. 2014(35):303-319.
[11] Michler A K. Aircraft Control Surface Deflection Using RBF-based Mesh Deformation[J]. International Journal for Numerical Methods in Engineering ,2001,88:996-1007.
[12] Beckert A and Wendland H. Multivariate interpolation for fluid–structure interaction problems using radial basis functions[J]. Aerospace Science and Technology ,2001,5:125–134.
[13] Rendall TCS and Allen CB. Reduced surface point selection options for efficient mesh deformation using radial basis functions[J]. Journal of Computational Physics,2010,229: 2810-2820.
[14] Mian H H, Wang Gang, Ye Zheng-yin. Numerical Investigation of Structural Geometric Nonlinearity Effect in High-Aspect-Ratio Wing using CFD/CSD Coupled Approach[J]. Journal of Fluids and Structures, 2014,49:186-201.
{{custom_fnGroup.title_cn}}
脚注
{{custom_fn.content}}