Aeroelasticity Analysis Method And Optimization Design For Aircraft Wing With Variable Camber Continuous Trailing Edge

The aerodynamic characteristics of airplane with elastic wing are influenced by the aeroelastic deformations because of the aerodynamic loads.If the loads distribution and stiffness distribution can be designed,the aeroelastic deformations of elastic-wing airplane can make advantage influences to its aerodynamics characteristics.So,the flight efficiency can be improved using the aeroelastic deformations.For the elastic-wing airplane with Variable Camber Continuous Trailing Edge Flaps(VCCTEF),the flaps can deflect according to flight conditions.So,the wing shape can change realtimely,and will influence the aerodynamics characteristic of airplane tremendously.The optimization design for flaps deflection angles of VCCTEF system under defferent flight conditions can make the airplane having good aerodynamics characteristics at multi-task profiles.However,the accuracy and efficiency of static aeroelasticity analysis method can influence the accuracy,reliability and design cycle of aeroelsticity optimization design directly.The core problem for aeroelasticity optimization design is how to couple static aeroelasticity analysis method with high-efficiency and highprecision,and optimization design method.Considering there are so many uncertainty elements in the real flight considtions,it is very important for improving flight performance under real flight conditions to do robust optimization design of flaps deflection angles of VCCTEF system considering the uncertainty elements.For above proplems,the nonlinear static aeroelasticity analysis method with high-efficiency and high-precision,the robust design optimization have been studied in this paper.The flaps deflection angles of VCCTEF system have been designed using deterministic and robust aeroelasticity optimization methods under different flight conditions.The approaches of aeroelsticity optimization for flaps deflection angles with deterministic and robust are established.The main works of this study are as follows:1.The high accuracy nonlinear computational aeroelasticity method is established,which considers aerodynamics nonlinear and structural geometry nonlinear.The RANS equations and linear or nonlinear static structural equations are coupled in this method.The RBF method is used for loads and displacements transferring in this method,which can keep the interpolation accuracy.Then,the interpolation method by coupling whole area and local area is established for the loads and displacements transferring of complex configurations.The interpolation method can make the loads and displacement transfer have more efficiency and accuracy.The mesh deformation method base on RBF&TFI technology has been improved in this paper,which considered the deformation ability and deformation efficiency.Three cases have been chosen to do the test of nonlinear static aeroleasticity analysis method in this paper.The F6 wing body configuration is used for testing the computational aeroelasticity method base on linear static structural equations.The effect of lift characteristic of high-lift configuration because of the aeroelastic deformation is studied.For the problem of structural large elastic deformation,the Common Research Model is studied by the computational aeroelasticity method base on linear and nonlinear structural solver.The difference of two results are studied.2.The two robust aeroelsticity optimization design systems are established base on the DKM and SKM respectively.First,the surrogate model modules base on DKM and SKM are built respectively after studing the deterministic Kriging surrogate model and Stochastic Kriging surrogate model.Then,the NFFD parameterized method module and NSGA-Ⅱ Genetic Algorithm module are built.The robust aeroelsticity optimization design systems are established by coupling all the modules.For the case of M6 wing,the aerodynamics robust optimizations are studied by considering the aeroelastic deformations.Two robust optimization are done base on the deterministic Kriging surrogate model and Stochastic Kriging surrogate model,respectively.The results show the robust optimization base on Stochastic Kriging surrogate model has better aerodynamics characteristic.3.The aerodynamics optimization design for VCCTEF system is done under the different flight conditions base on the deterministic Kriging surrogate model.The wing shape can deform with different flap deflection angles of VCCTEF system.In this paper,three flight conditions during cruise range are considered,i.e.,start point,middle point and end point of cruise range.The optimization design of flap deflection angles under the three flight conditions are done.During the optimizations,the influence of difference deflection angles between neighbouring flaps is considered.The optimization results show the drag characteristics of optimal configurations under three flight conditions have been improved abviously.Otherwise,the influence for lift characteristic of high-lift configurations with VCCTEF system is studied.The results show the difference flap deflection angles can influence the lift characteristic of high-lift configurations abviously,and have the potential to improve the lift characteristic of high-lift configurations.4.Based on the POD method and Kriging surrogate method,the reduced order model for static aeroelasticity computational method(SAEROM)is established.Three steps are taken during building SAEROM: A.The original aerodynamics are predicted according the design variables.The pressure coefficient for surface wall can be described by POD bases and its coefficients by using POD technology.The coefficient of POD bases can be predicted using Kriging surrogate model.Then the pressure coefficient for surface wall of original aerodynamics can be formed with very less time.B.Transferring the aerodynamics to the structral element model,do the static structral analysis.Then the aeroelastic deformations of servaral sections can be picked up.C.The aerodynamic distribution can be predicted base on the design variables and the aeroelastic formations of servaral sections using POD&Kriging method.Taking the underform Common Research Model(u CRM)as the test case,the efficient and accuracy of SAREROM are studied by comparing the results of full-order aeroelasticity solver and the solver base on the reduced order model.The influence for accurency of SAEROM of aeroelastic deformation sections distribustions and surrogate models.5.A system of aeroelasticity optimization design is established base on SAEROM.The SAEROM can be used to build the samples which are used during aeroelasticity optimization design.The SAEROM also can be used to update the surrogate model during the aeroelasticity optimization design.Comparing to the full-order aeroelasticity analysis,it can save 60% computation times of compuating the samples by using the SAEROM.Base on the u CRM configuration,the flap deflection angles of VCCTEF system are optimized using the aeroelasticity optimization design system base on SAEROM.Comparing to the original u CRM configuration,the drag coefficient of optimal u CRM+VCCTEF configuration reduce 2 counts.Comparing to the optimization without SAEROM,the efficiency of this aeroelasticity optimization design system base on SAEROM shows goodness.6.The aerodynamics robust design optimization for VCCTEF system is done base on the Stochastic Kriging surrogate model by considering the flight condition uncertainty and structural properties uncertainty.The u CRM+VCCTEF cruise configuration is optimized using the robust optimization system base in Stochastic Kriging model.After the robust optimization,the sensitiveness for freeflow Mach number and structral properties of optimal u CRM+VCCTEF configurations reduces obviously,and the robust improves.