Design of low Reynolds number airfoils. I

摘要: Low Reynolds number airfoils were designed for high lift-to-drag ratios. Design considerations of low Re-airfoils are discussed and design examples presented. It is shown that the performance advance critically depends on proper laminar separation transition control minimum profile drag coefficient with turbulator device drag. This close to possible by enforcing upper surface either directly means spanwise rows three-dimensional roughness elements, bleed or suction holes, indirectly destabilizing boundary layer backward facing steps, two-dimensional zig-zag tapes weak blowing. Pneumatic turbulators found be advantageous because they can adjusted different external flow conditions better than mechanical ones.