81 flow
result
of boundary layer separation dependant on pressure gradient
Flow separation only takes place in an Adverse pressure gradient
LOWSPEED AEROFOIL STALL
TrailingEdge stall t c 13
As α increases separation moves up
Marked as graduall fall of in C with α
Leading Edge Stall 9 t C 13
Sudden burst of a leading edge bubble
Marked by much more severefall off in
C with α
Separation bubble common on leading edges with local high curvature
Bubble length governed by Renumber
, Thin Aerofoil stall t C 10
Leading separation bubbleextending downstream
as α increases
Lower C and a gradualfalloff inC with α
COMPARISON
LIFT AUGMMENTATION
Increasing Max C
Methods
Trailing edge flap Increase camber
Slats flaps
flow control technology
Stagnation pointmovestolowersurface
moveddownto
C increased as
flap
increase camber
Sight decrease in α