VORTEX FLOW-CONTROL USING FILLETS ON A DOUBLE-DELTA WING

This article presents results from a subsonic numerical investigation on the effects of geometry modifications at the junction of the leading edge extension (LEX) and wing of a flat-plate cropped double-delta wing at moderate to high angles of attack. The baseline planform of the double-delta wing configuration consisted of a strake with a 76-deg leading-edge sweep and a wing with a 40-deg leading-edge sweep with sharp, beveled leading edges. The geometry modifications included various fillet shapes with planform areas equal to 1% of the baseline wing reference area. A hyperbolic grid generation method was developed and used in conjunction with an existing interactive grid generation system to create high quality C-O type multiblock grids about the configurations studied. The Euler and Reynolds averaged Navier-Stokes (RANS) equations were solved numerically using two finite-volume production flow solvers. The baseline configuration numerical results correlated well with existing published experimental data. Grid refinement using the RANS revealed vortex sheet tearing on the wing. Fillets enhanced the lift by 14% at low angle of attack, and 18% at high angle of attack with a slight improvement in lift-to-drag ratio. The fillets may be good candidates for roll control devices.