Comparison of Finite Difference Calculations of a Large Region of Recirculating Flow Near an Airfoil Trailing Edge,

Abstract

Calculations are presented for a turbulent boundary layer which separates upstream of a sharp trailing edge and results in a large region of recirculating flow and a curved downstream wake. The solutions obtained from two procedures that solve finite difference equations formulated with hybrid combinations fo upwind central and bounded skew upwind central difference approximations for convective terms, are compared. Numerical error was smaller, and accordingly less false diffusion was apparent, in the bounded skew calculations although there was no significant improvement in the agreement with experiment. Agreement between measured and calculated values of the lift coefficient was within 3 per cent and required representation of momentum transport and pressure gradient normal to the surface, but the measured drag coefficient was less than 80 per cent of that obtained in both calculations. Deficiencies are attributable, in part, to turbulence-model assumptions which do not represent the effects of stabilizing and destabilizing streamline curvature and the complex interaction of the backflow, pressure side and curved suction-side boundary layers in the vicinity of the rear stagnation point downstream of the trailing edge.

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1986
Accession Number
ADP005126

Entities

People

  • B. E. Thompson
  • L. Reis

Organizations

  • Imperial College London

Tags

DTIC Thesaurus Topics

  • Boundary Layer
  • Computational Fluid Dynamics
  • Difference Equations
  • Diffusion
  • Equations
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Layers
  • Mathematical Analysis
  • Pressure Gradients
  • Stagnation Point
  • Trailing Edges
  • Turbulent Boundary Layer

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Calculus or Mathematical Analysis
  • Fluid Mechanics and Fluid Dynamics.