Numerical Simulation And Investigation Of Aircraft Flutter

Flutter is one of the most important problems for aircraft and it has large impact on vehicle performance ,especially for new aircraft. The purpose of this thesis is to study numerical methods, develop analytic software for simulate flutter numerically in transonic region and provide service for aircraft design.Computation of aircraft flutter in time domain is studied in this thesis. The unsteady aerodynamic forces obtained from high-level Computational Fluid Dynamics(CFD) methods are coupled with structural dynamics tools to simulate the character of aircraft structure.The first chapter is the introduction, in which the development and status of numerical simulation for flutter are reviewed , the present research work of this thesis is also introduced briefly in this chapter.In the second chapter, the numerical methods for simulating unsteady flows are introduced ,which are validated through two unsteady airfoil examples ,the influence of turbulent model ,time accuracy and grid resolution are discussed.Charter 3 presents the numerical methods for simulating of airfoil flutter. NACA64A006 airfoil is selected as an example, and the effect of grid resolution, time-step sizes ,rigid grid and flexible grid are also discussed.Charter 4 presents numerical methods for simulating of wing flutter and dynamic mesh technology which used in this thesis. The AGARD 445.6 standard aeroelastic wing test case is applied to validate the resulting aeoelastic solver. The aeroelastic boundaries are calculated from subsonic to supersonic flow, and the effect of grid resolution, time-step sizes ,initial flow field to flutter velocity are studied.The last chapter is the concluding remarks ,the deficiency of present work and future work are pointed out.