Accession Number : ADA298050

Title :   Large Eddy Simulation of Turbulent Flow Over an Airfoil.

Descriptive Note : Final technical rept. 30 Sep 93-29 Mar 95,

Corporate Author : STANFORD UNIV CA DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Moin, Parviz

PDF Url : ADA298050

Report Date : MAY 1995

Pagination or Media Count : 17

Abstract : The turbulent flow over a NACA 4412 airfoil at angle of incidence corresponding to maximum lift (12 degree) has been computed via large-eddy simulation. Two different numerical approaches, one based on a conventional structured mesh and one with a more economical unstructured mesh, have been employed. Results from both simulations differ considerably from each other and from the available experimental data. Differences are found with respect to occurrence of transition near the suction peak and with respect to the amount of backflow (incipient separation) near the trailing edge. The unstructured mesh code predicts rapid boundary layer growth and separation near the trailing edge, whereas the flow remains attached in the structured mesh simulation. It was concluded that a better matching of the transition mechanism (boundary layer tripping) which was employed in the experiments is paramount for an accurate simulation of this flow and for convergence of solutions from the two codes. (AN)

Descriptors :   *TURBULENT FLOW, *EDDIES(FLUID MECHANICS), *FLOW VISUALIZATION, *HYDRODYNAMIC CODES, MATHEMATICAL MODELS, COMPUTERIZED SIMULATION, FINITE ELEMENT ANALYSIS, COMPUTATIONAL FLUID DYNAMICS, VORTEX SHEDDING, MESH, FINITE DIFFERENCE THEORY, FLOW FIELDS, CONVERGENCE, NUMERICAL METHODS AND PROCEDURES, BOUNDARY LAYER TRANSITION, NAVIER STOKES EQUATIONS, ANGLE OF INCIDENCE, FLOW SEPARATION, INCOMPRESSIBLE FLOW, TRAILING EDGES, BACKFLOW, GASEOUS DIFFUSION SEPARATION.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE