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Cartes-fiches
Assuming ISA Conditions, and no compressibility effects, if an aeroplane maintains straight and level flight at the same anlge of attack at two different altitudes, the:
IAS is the same at both altitudes.
two different altitudes, same AoA = IAS is the same.
Assuming ISA Conditions, and no compressibility effects, if an aeroplane maintains straight and level flight at the same anlge of attack at two different altitudes, the:
TAS is lower at the lower altitude.
Altitude ~ TAS
An Aeroplanes AoA is the angle between:
speed vector and lonitudinal axis.
AIRPLANES AoA is between:
speed vector and lonitudinal axis.
Which of the following planforms gives the HIGHEST local profile lift coefficient at the wingroot?
Rectangular
Highest lift coefficient = Rectangular!
The fundemental difference between the areodynamic charecteristics of two and three-dimensional flow is that, in a three-dimensional flow about a wing:
a spanwise component exists in addition to the chordwise speed component.
in 3-D: a spanwise component + chordwise speed component!
flow on the upper surface:
The flow on the upper surface of the wing has a component in wing root dircetion.
flow above the wing has a component in wing root direction.
Airplane accerlerates from 80 to 160 with load factor 1.
The induced drag coefficient alters with factor 1:16
and induced drag with factor 1/4.
Acceleration: doubles
CDi: 1/16
Di 1/4
increasing AR on induced Drag:
it is reduced because the effect of wing-tip vortices is reduced.
increasing AR # decreasing induced Drag.
Induced drag is created by the:
spanwise flow pattern* resulting in the tip vortices.
*bilden
Di = spanwise flow pattern = tip vortices.
AR and induced Drag (Relationship)
a decrease in AR increases the induced drag
AR "^" : Di "v"
What is the effect on induced drag of mass and speed changes?
Induced Drag decreases with increasing speed and
induced drag decreases with decreasing weight!
DI ~ Weight
DI anti ~ speed
The induced drag increases as the lift coefficient increases.
DI ~ CL (lift coefficient)
High AR, as compared with Low AR has the effect:
decreasing induced drag and critical angle of attack.
High AR = decreased DI and AoA
TAS & Induced Drag
"TAS increases - DI decreases"
TAS anti ~ DI ((Diagramm) x und TAS))
CDi (The induced drag coefficient) is proportional with:
CL²
CDi ~ CL²
Induced AoA is the result of:
downwash due to tip vortices.
Induced angle of attack results from downwash due to tip vortices.
The span-wise flow on an unswept wing is from the:
lower to the upper surface via wing tip.
span-wise flow on an unswept wing:
lower to the upper surface via the wing tip!
local flow pattern:
By fitting winglets to the wing tip the strength of the wing tip vortices is reduced, which in turn reduces induced drag.
fitting winglets, reduces induced drag.
