AMT 280 - Lab 5 - Airfoil Flap & Slat Effectiveness(1).pptx...

AMT 280 Laboratory Period 5
Slats and Flaps

Increasing Camber or Energy Additions to the Boundary Layer
Wind
tunnel
split
Wind
tunnel
Movable slat

AMT 280 Laboratory
Airfoil Slat & Flap Effects
•
One of the ways to improve the versatility and flight
characteristics of an airplane is to install wing flaps and
slats. Flaps are designed so that when extended they
not only provide higher lift but also have higher drag.
This allows a steep angle of descent at slow airspeeds
with but keeps the engines spooled up power output-
go-around
•
Objectives
–
Observe the effects of the flap and the slat on a model airfoil
with respect to lift and drag.
–
Observe the general airflow pattern over the airfoil while using
flaps and slats.
–
To observe the creation of wing tip vortices

Airfoil Slat & Flap Effects
Effect of high lift devices
•
The primary purpose of high lift devices
(flaps, slots, slats, etc.) is to increase the
C
Lmax
of the aircraft and to reduce the stall
speed.
•
Take-off and landing speeds are also
reduced and engines are spooled up.

Krueger/Leading edge flap
•
Krüger flaps were invented by
Werner Krüger in 1943 and
evaluated in the wind tunnels in
Göttingen, Germany. One of the
earliest applications was the
Boeing 707 in 1954.
•
The flap was added to prevent
wing stall with an extreme attitude
take-off with the tail dragging on
the runway, a scenario that had
already caused two deHavilland
Comet accidents.

Slotted flap – high-
energy air from the
lower surface is ducted
to the flap upper
surface.
This air from the slot
accelerates the upper
surface boundary layer
and delays airflow
separation to some
higher lift coefficient.
This flap causes much
greater increases in
C
Lmax
than the plain or
split flap and section
drags are much lower
Fowler-Flap

Slats also called leading edge
devices