Accession Number : ADA299979

Title :   An Incompressible 3-D Navier-Stokes Method with Adaptive Hybrid Grids.

Descriptive Note : Doctoral thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Chen, Alice J.

PDF Url : ADA299979

Report Date : 22 SEP 1995

Pagination or Media Count : 231

Abstract : A numerical method has been developed for the unsteady Navier-Stokes equations of incompressible flow in three dimensions. The momentum equations, combined with a pressure correction equation, are solved employing a non-staggered grid which results in a simpler formulation compared to the classical approach of using staggered meshes. The momentum equations are solved explicitly using a finite volume algorithm, while the pressure Poisson equation is discretized using the Galerkin finite element method and implicitly solved. The grid is formed with hybrid (prismatic/tetrahedral) elements. Equation adaptation is utilized, the Navier-Stokes equations are solved in the prismatic region, which includes the viscous region, and the Euler equations are solved in the tetrahedral region, which is inviscid. Adaptive local grid refinement of the prism and tetrahedral cells is employed in order to optimize the mesh to the flow solution. Validation of the algorithm is performed using experimental and other numerical data, and demonstrate the accuracy and robustness of the unsteady three-dimensional method. An additioual study is conducted using an existing two-dimensional incompressible Navier-Stokes solver. The two-dimensional solver is applied to predict the hydrodynamic forces on a circular cylinder due to reversing flows.

Descriptors :   *COMPUTATIONAL FLUID DYNAMICS, *NAVIER STOKES EQUATIONS, *INCOMPRESSIBLE FLOW, *THREE DIMENSIONAL FLOW, MATHEMATICAL MODELS, ALGORITHMS, COMPUTERIZED SIMULATION, OPTIMIZATION, FINITE ELEMENT ANALYSIS, GRIDS, ACCURACY, THESES, VORTICES, MESH, INTERPOLATION, CONVERGENCE, TWO DIMENSIONAL FLOW, UNSTEADY FLOW, NUMERICAL METHODS AND PROCEDURES, INVISCID FLOW, FREE STREAM, VISCOUS FLOW, HYDRODYNAMICS, PRESSURE DISTRIBUTION, REYNOLDS NUMBER, POISSON EQUATION, STEADY FLOW, CAVITATION, PRISMATIC BODIES.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE