Accession Number : ADA191336

Title :   Tip Vortices of Isolated Wings and Helicopter Rotor Blades.

Descriptive Note : Final rept. Nov 84-Nov 87,

Corporate Author : JAI ASSOCIATES INC MOUNTAIN VIEW CA

Personal Author(s) : Srinivasan, Ganapathi R

PDF Url : ADA191336

Report Date : Dec 1987

Pagination or Media Count : 86

Abstract : Thin layer Navier-Stokes equations are solved numerically for simulating the flowfields of isolated wings and helicopter rotor blades with a particular emphasis on understanding the formation and roll-up of tip vortices in subsonic and transonic flows. Several test cases consisting of wings and rotor blades of different planforms have been considered to examine the influence of the tip-cap shape, the tip-planform, the freestream Mach number, and the effect of centrifugal forces of rotation. A fairly good definition of the formation and roll-up of the tip vortex is demonstrated for all the cases considered here. Finally, the calculated lift, drag and pitching-moment coefficients agree well with the experimentally determined values, where available. Alternate methods of simulating the hovering rotor flowfields in blade-fixed mode that have the circulation distribution as hovering blade are explored. The results and discussion are presented. Keywords: Viscous, Unsteady flows; Zonal grid topology; Thin layer Navier-Stokes; Tip vortices; Inertial reference frame; Three-dimensional flow separation; Steady flows, Fluid dynamics.

Descriptors :   *ROTOR BLADES(ROTARY WINGS), *VORTICES, *WING TIPS, BLADES, CENTRIFUGAL FORCE, CIRCULATION, DISTRIBUTION, DRAG, FLOW FIELDS, FLOW SEPARATION, FLUID DYNAMICS, FREE STREAM, GRIDS, HELICOPTER ROTORS, HOVERING, ISOLATION, LAYERS, MACH NUMBER, NAVIER STOKES EQUATIONS, ROTATION, ROTOR BLADES, ROTORS, STEADY FLOW, SUBSONIC FLOW, THINNESS, THREE DIMENSIONAL FLOW, TOPOLOGY, TRANSONIC FLOW, UNSTEADY FLOW, VISCOUS FLOW, WINGS, FRONT ENDS AND SURFACES

Subject Categories : Aerodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE