Numerical Study Of Active Control Of Slender Delta Wing Rock

When the modern fighter flies at high angle of attack,the aerodynamic force is strongly nonlinear and unsteady,which reduces the longitudinal and lateral instability of the aircraft.As a result,the problem of dynamic stability of aircraft,in which the wing rock(wing rock)is the main part,arises.When aircraft rock,aerodynamic,motion and control are further coupled,which limits the performance of the control system,thus affecting the combat effectiveness of fighter aircraft,and even threatening the safety of aircraft maneuvering flight.At present,a large number of literatures on the numerical simulation and experimental study of rock movement have been published at home and abroad,forming the basic understanding of rock phenomenon and physical mechanism.However,there are few literatures about the control of delta wing rock and roll,and most of them focus on the related control methods,lacking of enough attention on the aerodynamic,dynamic and control coupling.In this paper,based on the structural dynamic mesh deformation technique,the control surface deflection is realized for the delta wing rock problem.The N-S equation,the single-degree-of-freedom Euler rigid body dynamics equation and the classical control law are solved by coupling.The numerical simulation of the active control process of delta wing rock is realized,and the dynamic characteristic mechanism analysis of the coupling of delta wing rock and control is carried out,which provides support for realizing the roll control of delta wing.Firstly,for the unsteady problem with moving boundary,the equations of fluid motion in arbitrary Lagrangian coordinates are introduced,and the "geometric conservation law" is introduced to modify the discrete equations,and the rolling motion model of single degree of freedom is established.Secondly,based on the structured dynamic grid technology,the transfinite interpolation(TFI)method,the radial basis function(RBF)method and the RBF＿TFI method are studied,and the related grid motion programs are established.Then the numerical simulation of the free roll of delta wing and forced oscillation of NACA0012 airfoil is carried out to verify the computational ability of the program for dynamic problems and unsteady problems with moving boundary.On this basis,the motion characteristics of delta wing with 80 degree swept back belt control surface are analyzed by numerical simulation.Coupled with classical control method,the active control process of delta wing rock is numerically simulated,and the control effects of proportional,differential and proportional differential controllers on delta wing rock movement are further compared.It establishes the foundation for the control method research of delta wing rock movement.