Assessment of numerical uncertainty around shocks and corners on blunt trailing-edge supercritical airfoils

Numerical uncertainties are quantified to guide grid refinement in calculat ions of subsonic and transonic flow around supercritical airfoils with blun t and divergent trailing edges. The concept of grid convergence index (GCI) , which extrapolates error estimates from arbitrary grid refinement ratios to those equivalent to grid doubling, was used to assess the adequacy of gr id refinement. Values of grid convergence indices were calculated from aero dynamic-force and surface-pressure coefficients that were calculated by sol ution of compressible Reynolds-averaged Navier-Stokes equations on several grids, with emphasis placed on the effect of the shock and the corners on a ccuracy. The strategies described for grid refinement calculated base press ure to within 2% GCI and shock location within 1%, of chord, and shows nume rical factors are more significant to calculated values of aerodynamic drag than lift. (C) 2001 Elsevier Science Ltd. All rights reserved.