Chapter 13 - Stalling Flashcards
What happens at a stall
AOA is too steep, separation point and transition point move forward. adverse pressure gradient increases causing the turbulent layer to separate and stall.
Also note speed reduces as the AOA increases using more energy up.
Sharp leading edges require how much energy at the LE
High
High Aspect wing has what size induced angle?
small
In straight and level flight before stall a High AOA has what effect on Lift and Drag
Lift remain constant
Drag increases
IAS decreasing
at stall point lift will decrease as well
A glider will stall at which AOA and where
low and at the tip
A highly tapered/ swept wing has what effects on the buffet tip CofP and pitch Downwash to the tail plane
No natural buffet
tip stall causes wing drop
CofP moves forward causing a pitch up
Downwash increases the downforce on the tailplane adding to pitch up
Where does a rectangle wing stall first and how big are the vortices
Root and small
Where does a swept wing stall first and the vortices are?
Tip and small
Which is the worse combination for deep stall
T tail with swept back wings
Wing fences, vorticons, sawtooth and knotch all reduce what
spanwise flow
Which speed aerofoil do we get a progressive stall
low speed
What does VS0 represent
Stall speed for landing config
What does VSR represent
Stall speed reference which is given by the manufacture
VS1G
Stall speed at load factor of 1G
How can we ensure the root stalls first artificially?
Sharpen the LE
Wing loading is
wing area
Cessna is said to have which type of wing loading and stall speed
Low wing loading
Small stall speed
In a manoeuvre what happens to stall speed and stall AOA
Stall speed increases
Stall AOA decreases
Leading edge flaps do what to stall AOA
increase the stalling AOA
Dropping the gear will increase the stall speed why
because the CofG moves forward requiring more downforce from the tail plane to stay straight and level.
Requiring more speed
Swept back will pitch in a stall
up
When using TAS the streamlines are effected by?
Compressibility and lose much more energy being closer to the wings surface
At 40,000 TAS is what of IAS
double
