FLOW FEATURE NEAR UNSWEPT AND SWEPT FINIT SPAN WING WITH SMOOTH AND WAVY SURFACE AT STALL ANGLE OF ATTACK

Incompressible flow feature at near stall angle off attack on classical and wavy surface wing with aspect ratio λ = 3,7 at Reynolds number 1,5 · 10⁵ was investigated. Such kinds of the wings at the same Reynolds number are employing on micro air vehicle. Vitality of the small aircraft at near ground atmospheric condition flight depends from predictable wing behavior at near stall angle of attack. Separation and attached flow structure at lee surface of wavy and classical wing was shown by oil-film visualization at sweep and no sweep angle condition. It was shown the wavy wing at no sweep condition has the stall angle of attack lager than classical one. At post-stall angle of attack α = 9º for classical wing sweep angle increasing from 15º to 45º results to changing from separation flow regime to attached one. On wavy wing at the same angle of attack and sweep angle from 0º to 45º the attached flow is observed only. In practice, this means that micro air vehicle will easy controlling by automatic system and will fall in stall regime rarely.

Keywords:
low Reynolds number, swept wing streamlining, wavy surface, boundary layer, separation bubble, laminarturbulent transition, oil-film visualization. 
УДК 533.69.048

FLOW FEATURE NEAR UNSWEPT AND SWEPT FINIT SPAN WING WITH SMOOTH AND WAVY SURFACE AT STALL ANGLE OF ATTACK