The temporal stability and growth characteristics of three-dimensional supersonic shear layers are numerically investigated. An explicit time-marching scheme that is second-order accurate in time and fourth-order accurate in space is used to study this problem. The shear layer is excited by instability waves computed from a linear stability analysis and random initial disturbances. At low convective Mach numbers, organized vortical structures develop both for the random disturbance and the modal disturbance cases. At supersonic convective Mach numbers, vortical structures develop initially but are not sustained in time. Temporal growth of disturbances is found to be a strong function of the convective Mach number.


Analysis of stability and trasitionin flat plate compressible boundary layers using linear stability theory
Atalayer, H. Senem; Özge, Serkan; Department of Aerospace Engineering (2004)
In this study, numerical investigations of stability and transition problems were performed for 2D compressible boundary layers over a flat plate in adiabatic wall condition. Emphasis was placed on linear stability theory. The mathematical formulation for 3D boundary layers with oblique waves including detailed theoretical information was followed by use of the numerical techniques for the solution of resulting differential system of the instability problem, consequently an eigenvalue problem. First, two-di...
Kayran, Altan (1990-07-01)
An analysis is presented for the free vibration characteristics of isotropic and laminated composite truncated circular conical shells including transverse shear deformation. All components of translatory and rotatory inertia are included. The applicability of linear shell theory due to Reissner is assumed, and governing equations are solved for the natural frequencies and mode shapes by using a combination of modal iteration and transfer matrix approach for different boundary conditions. Natural frequencie...
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...
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...
Aerodynamic design and optimization of horizontal axis wind turbines by using bem theory and genetic algorithm
Ceyhan, Özlem; Tuncer, İsmail Hakkı; Department of Aerospace Engineering (2008)
An aerodynamic design and optimization tool for wind turbines is developed by using both Blade Element Momentum (BEM) Theory and Genetic Algorithm. Turbine blades are optimized for the maximum power production for a given wind speed, a rotational speed, a number of blades and a blade radius. The optimization variables are taken as a fixed number of sectional airfoil profiles, chord lengths, and twist angles along the blade span. The airfoil profiles and their aerodynamic data are taken from an airfoil datab...
Citation Formats
İ. H. Tuncer, “NUMERICAL-SIMULATION OF 3-DIMENSIONAL SUPERSONIC FREE SHEAR LAYERS,” AIAA JOURNAL, pp. 871–872, 1992, Accessed: 00, 2020. [Online]. Available: