Transonic Non-steady Flow And The Value Of Flutter Analysis Technology Research

The research of this dissertation is focused on how to simulate numerically the steady and unsteady transonic inviscid flows around two-dimensional models, and viscous flows around wing, wing-body configuration, T-tail by computational fluid dynamics method. On the basis, the transonic flutter characteristics of aircraft are investigated.Two-dimensional unstructured grids is constructed by advanced-front method (AFM), classic linear spring analogy is used for generating moving grids. The unsteady integral Euler equations is solved by finite volume method, to research the characteristics of a new flutter exciter system and unsteady flow fields of two-dimensional fuselage with fuselage flap.Three-dimensional structured grids of aircraft are constructed by commercial software GRIDGEN, and the body-fitted viscous moving grids are generated by algebraic finite integration and a kind of grid modified technology. Then the steady and unsteady transonic viscous flows are numerically simulated. The three-dimensional unsteady Navier-Stokes equations are solved by using the implicit LU-NND algorithm, with Baldwin-Lomax turbulent model. On the basis of simulating unsteady viscous flows, coupling the structure dynamics equations, the problem of flutter is investigated for wings, empennage and wing-body configuration.On the basis, many examples, simulating the steady and unsteady viscous flows around wings, are given in this paper. The transonic flutter characteristics are investigated for several wings, empennage and wing-body configuration, flutter critical speeds are numerically simulated. Some numerical results are agreed well with other reference data. The method and the program presented in this paper areverified.