A method for static aeroelastic trim analysis and flight loads computation of a flexible aircraft with large deformations has been presented in this paper,which considers the geometric nonlinearity of the structure an...A method for static aeroelastic trim analysis and flight loads computation of a flexible aircraft with large deformations has been presented in this paper,which considers the geometric nonlinearity of the structure and the nonplanar effects of aerodynamics.A nonplanar vortex lattice method is used to compute the nonplanar aerodynamics.The nonlinear finite element method is introduced to consider the structural geometric nonlinearity.Moreover,the surface spline method is used for structure/aerodynamics coupling.Finally,by combining the equilibrium equations of rigid motions of the deformed aircraft,the nonlinear trim problem of the flexible aircraft is solved by iterative method.For instance,the longitudinal trim analysis of a flexible aircraft with large-aspect-ratio wings is carried out by both the nonlinear method presented and the linear method of MSC Flightloads.Results obtained by these two methods are compared,and it is indicated that the results agree with each other when the deformation is small.However,because the linear method of static aeroelastic analysis does not consider the nonplanar aerodynamic effects or structural geometric nonlinearity,it is not applicable as the deformations increase.Whereas the nonlinear method presented could solve the trim problem accurately,even the deformations are large,which makes the nonlinear method suitable for rapid and efficient analysis in engineering practice.It could be used not only in the preliminary stage but also in the detail stage of aircraft design.展开更多
A method for static aeroelastic analysis based on the high-order panel method and modal method is presented. The static aeroelastic characteristics of flexible wings are investigated using this method. Three-dimension...A method for static aeroelastic analysis based on the high-order panel method and modal method is presented. The static aeroelastic characteristics of flexible wings are investigated using this method. Three-dimensional aerodynamic models of flexible wings are constructed based on the geometry of wing configuration, and the modal method is adopted to achieve the fluid-structure coupling. The static aeroelastic characteristics of the AGARD445.6 wing and a low-aspect-ratio wing are investigated in this study. The influences of elastic structural deformation on aerodynamic forces are studied with an emphasis analyzing the aerodynamic coefficients, wing root loads, structural deformation and pressure distribution of different sections, and results are compared with the results from wind-tunnel tests and the elastic results based on experimental aerodynamic forces. It is concluded that aerodynamic forces can be accurately calculated with the high-order panel method. The method presented in this study is feasible, credible and efficient. Comprehensive static aeroelastic characteristics can be provided by the method for early phases of aircraft design.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11172025,91116005)the Research Fund for the Doctoral Program of Higher Education of China (Grant No.20091102110015)
文摘A method for static aeroelastic trim analysis and flight loads computation of a flexible aircraft with large deformations has been presented in this paper,which considers the geometric nonlinearity of the structure and the nonplanar effects of aerodynamics.A nonplanar vortex lattice method is used to compute the nonplanar aerodynamics.The nonlinear finite element method is introduced to consider the structural geometric nonlinearity.Moreover,the surface spline method is used for structure/aerodynamics coupling.Finally,by combining the equilibrium equations of rigid motions of the deformed aircraft,the nonlinear trim problem of the flexible aircraft is solved by iterative method.For instance,the longitudinal trim analysis of a flexible aircraft with large-aspect-ratio wings is carried out by both the nonlinear method presented and the linear method of MSC Flightloads.Results obtained by these two methods are compared,and it is indicated that the results agree with each other when the deformation is small.However,because the linear method of static aeroelastic analysis does not consider the nonplanar aerodynamic effects or structural geometric nonlinearity,it is not applicable as the deformations increase.Whereas the nonlinear method presented could solve the trim problem accurately,even the deformations are large,which makes the nonlinear method suitable for rapid and efficient analysis in engineering practice.It could be used not only in the preliminary stage but also in the detail stage of aircraft design.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60736025, 90716006 and 10902006)the Doctoral Program Foundation of Institutions of Higher Education of China (Grant No. 20091102110015)the Major Programs of China National Space Administration (Grant No. D2120060013)
文摘A method for static aeroelastic analysis based on the high-order panel method and modal method is presented. The static aeroelastic characteristics of flexible wings are investigated using this method. Three-dimensional aerodynamic models of flexible wings are constructed based on the geometry of wing configuration, and the modal method is adopted to achieve the fluid-structure coupling. The static aeroelastic characteristics of the AGARD445.6 wing and a low-aspect-ratio wing are investigated in this study. The influences of elastic structural deformation on aerodynamic forces are studied with an emphasis analyzing the aerodynamic coefficients, wing root loads, structural deformation and pressure distribution of different sections, and results are compared with the results from wind-tunnel tests and the elastic results based on experimental aerodynamic forces. It is concluded that aerodynamic forces can be accurately calculated with the high-order panel method. The method presented in this study is feasible, credible and efficient. Comprehensive static aeroelastic characteristics can be provided by the method for early phases of aircraft design.
