Computation of external flow around rotating bodies

Gönç, L. Oktay
A three-dimensional, parallel, finite volume solver which uses Roe's upwind flux differencing scheme for spatial and Runge-Kutta explicit multistage time stepping scheme for temporal discretization on unstructured meshes is developed for the unsteady solution of external viscous flow around rotating bodies. The main aim of this study is to evaluate the aerodynamic dynamic stability derivative coefficients for rotating missile configurations. Arbitrary Lagrangian Eulerian (ALE) formulation is adapted to the solver for the simulation of the rotation of the body. Eigenvalues of the Euler equations in ALE form has been derived. Body rotation is simply performed by rotating the entire computational domain including the body of the projectile by means of rotation matrices. Spalart-Allmaras one-euqation turbulence model is implemented to the solver. The solver developed is first verified in 3-D for inviscid flow over two missile configurations. Then inviscid flow over a rotating missile is tested. Viscous flux computation algorithms and Spalarat-Allmaras turbulence model implementation are validated in 2-D by performing calculations for viscous flow over flat plate, NACA0012 airfoil and NLR 7301 airfoil with trailing edge flap. The ALE formulation is validated in 2-D on a rapidly pitching NACA0012 airfoil. Afterwards three-dimensional validation studies for viscous, laminar and turbulent flow calculations are performed on 3-D flat plate problem. At last, as a validation test case, unsteady laminar and turbulent viscous flow calculations over a spinning M910 projectile configuration are performed. Results are qualitatively in agreement with the analytical solutions, experimental measurements and previous studies for steady and unsteady flow calculations.


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Gönç, L.O.; Ak, M.A.; Tuncer, İsmail Hakkı; Aksel, M.H. (2006-01-01)
This paper presents the development of a 3-D parallel flow solver for turbulent flows around rotating bodies using unstructured grids. Cell centered finite volume solver which employs Roe's upwind flux differencing scheme, Spalart-Allmaras turbulence model and Runge-Kutta explicit multistage time stepping scheme is presented. Arbitrary Lagrangian Eulerian (ALE) formulation is implemented for moving grids. The computational grid is partitioned by METIS and PVM is used for inter-process communication. The mai...
Mathematical Modeling of Turbulent Flows of Newtonian Fluids in a Concentric Annulus with Pipe Rotation
SORGUN, MEHMET; Aydın, İsmail; ÖZBAYOĞLU, Evren; SCHUBERT, J J (2012-03-01)
In this study, a mathematical model is proposed to predict flow characteristics of Newtonian fluids inside a concentric horizontal annulus. A numerical solution, including pipe rotation, is developed for calculating frictional head losses in concentric annuli for turbulent flow. Navier-Stokes equations are numerically solved using the finite differences technique to obtain the velocity field. Experiments with water are performed in a concentric annulus with and without pipe rotation. Average fluid velocitie...
Exact analytical solution of the internal friction associated with a geometric kink chain oscillating in an atmosphere of paraelastic interstitials and decorated by a dragging point defect
Oğurtanı, Tarık Ömer (American Physical Society (APS), 1989-8-15)
The partial differential equation which describes the geometric kink chain oscillating in an atmosphere of uniformly distributed paraelastic interstitials and, in addition, decorated by a dragging point defect at the midpoint, is solved exactly with use of the Laplace-transformation technique. The internal friction coefficient and the modulus defect are obtained in closed forms which indicate the existence of two separate peaks. The Cole-Cole diagrams are also investigated which show irrevocably the splitti...
Citation Formats
L. O. Gönç, “Computation of external flow around rotating bodies,” Ph.D. - Doctoral Program, Middle East Technical University, 2005.