A dragonfly wing airfoil is essentially a thin plate, whose upper and lower surface velocities can be closely approximated by
ue(x)V∞ = (xc)−b(upper surface) (E1.22)
ue(x)V∞ = (xc)+b(lower surface) (E1.23)
Use the following case-sensitive typed names for the various symbols.
Symbol
x
c
b
V∞
Typed
x
c
b
V
Note: For each of the questions in this Problem, there is more than one solution method which can be used. Any of the methods, if applied correctly, will be marked correct.
LIFT (2 points possible)
1) If this airfoil were to be modeled as a simple vortex sheet, what would be the appropriate sheet strength (defined positive clockwise)?
γ(x)=- unanswered
2) Determine the 2D lift coefficient of this airfoil for b=0.05.
Round your answer to two significant digits.
cℓ=- unanswered
You have used 0 of 2 submissions
DRAG (4 points possible)
3) The dragonfly has a wing chord of 0.01 m, and can fly at 10 m/s. Assume roughly sea level viscosity ν=1.45×10−5m2/s. Determine the momentum thickness θ on the upper and lower surfaces at the trailing edge, again for b=0.05. Specify the results in meters.
Round your answer to two significant digits.
upper surface θTE=- unanswered
lower surface θTE= - unanswered
4) What is the overall 2D profile drag for this airfoil in this condition? Round your answer to two significant digits.
cd=- unanswered
5) What is the 2D lift-to-drag ratio for this airfoil in this condition? Round your answer to two significant digits.
cℓcd=- unanswered
1 answer