Development of a closely coupled approach for solution of static and dynamic aeroelastic problems

Başkut, Erkut
In this thesis a fluid-structure coupling procedure which consists of a commercial flow solver, FLUENT, a finite element structural solver, MSC/NASTRAN, and the coupling interface between the two disciplines is developed in order to solve static and dynamic aeroelastic problems. The flow solver relies on inviscid Euler equations with finite volume discretization. In order to perform faster computations, multiple processors are parallelized. Closely coupled approach is used to solve the coupled field aeroelastic problems. For static aeroelastic analysis Euler equations and elastic linear structural equations are coupled to predict deformations under aerodynamic loads. Linear interpolation using Alternating Digital Tree data structure is performed in order to exchange the data between structural and aerodynamic grid. Likewise for dynamic aeroelastic analysis, a numerical method is developed to predict the aeroelastic response and flutter boundary. Modal approach is used for structural response and Newmark algorithm is used for time-marching. Infinite spline method is used to exchange displacement and pressure data between structural and aerodynamic grid. In order to adapt the new shape of the aerodynamic surface at each aeroelastic iteration, Computational Fluid Dynamic mesh is moved based on spring based smoothing and local remeshing method provided by FLUENT User Defined Function. AGARD Wing 445.6 and a generic slender missile are modeled and solved with the developed procedure and obtained results are compared with numerical and experimental data available in literature.


Assessment of an iterative approach for solution of frequency domain linearized euler equations for noise propagation through turbofan jet flows
Dizemen, İlke Evrim; Yörükoğlu, Yusuf; Department of Aerospace Engineering (2007)
This study, explores the use of an iterative solution approach for the linearized Euler equations formulated in the frequency domain for fan tone noise propagation and radiation through bypass jets. The aim is to be able to simulate high frequency propagation and radiation phenomena with this code, without excessive computational resources. All computations are performed in parallel using MPI library routines on a computer cluster. The linearized Euler equations support the Kelvin-Helmholtz type convective ...
Nonlinear flutter calculations using finite elements in a direct Eulerian-Lagrangian formulation
Seber, Guclu; Bendiksen, Oddvar O. (American Institute of Aeronautics and Astronautics (AIAA), 2008-06-01)
A fully nonlinear aeroelastic formulation of the direct Eulerian-Lagrangian computational scheme is presented in which both structural and aerodynamic nonlinearities are treated without approximations. The method is direct in the sense that the calculations are done at the finite element level, both in the fluid and structural domains, and the fluid-structure system is time-marched as a single dynamic system using a multistage Runge-Kutta scheme. The exact nonlinear boundary condition at the fluid-structure...
Time-domain calculation of sound propagation in lined ducts with sheared flows
Özyörük, Yusuf (American Institute of Aeronautics and Astronautics (AIAA), 2000-05-01)
A recent application of the time-domain equivalent of the classical acoustic impedance condition, i.e., the particle displacement continuity equation, to numerical simulations of a Bow-impedance tube in the time domain yielded reasonably good results with uniform mean flows. The present paper extends this application to include sheared mean-flow effects on sound propagation over acoustically treated walls. To assess the prediction improvements with sheared flows, especially at relatively high Mach numbers, ...
AKGUN, MA (American Institute of Aeronautics and Astronautics (AIAA), 1994-02-01)
A new family of modal methods for the calculation of eigenvector derivatives in non-self-adjoint systems with a singular coefficient matrix is developed. The family contains the modal and modified modal methods as a subset. In the family, the component of the mth eigenvector in the expansion of the derivative of the jth eigenvector is multiplied by various powers of the eigenvalue ratio lambda(i)/lambda(m), thereby accelerating convergence. The family of methods is applied to a self-adjoint example problem,...
Computational study of subsonic flow over a delta canard-wing-body configuration
Tuncer, İsmail Hakkı (American Institute of Aeronautics and Astronautics (AIAA), 1998-07-01)
Subsonic flowfields over a close-coupled, delta canard-wing-body configuration at angles of attack of 20, 24,2, and 30 deg are computed using the OVERFLOW Navier-Stokes solver Computed flowfields are presented in terms of particle traces, surface streamlines, and leeward-side surface pressure distributions for the canard-on and -off configurations. The interaction between the canard and the wing vortices, wing vortex breakdown, and the influence of the canard on vortex breakdown are identified, The comparis...
Citation Formats
E. Başkut, “Development of a closely coupled approach for solution of static and dynamic aeroelastic problems,” M.S. - Master of Science, Middle East Technical University, 2010.