1.16 From Eq. (1.59), in the text,
w =
or,
As given in Section 1.11, at standard sea level temperature is
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1.17 From Eq. (1.60)
The heat transfer into the surface is -0.03 MW/m2, and from Section 1.11, the
thermal conductivity at standard sea level temperature is
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k = 2.53 x 10-2 J/(m)(s)(K)
= -0.03 MW/m2 = -0.03 x 106 W/m2
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1.18 (a) At standard sea level, from Appendix E, ρ∞ = 0.002377 slug/(ft3). Also,
from Section 1.11, μ∞ = 3.7373 x 10-7 slug/(ft)(s). Putting the velocity in
consistent units,
V∞ = (200) = 293.3 ft/sec
Thus,
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1.19 From Figure 1.65, we have the normal and tangential force coefficients at
3-degres angle of attack given as 0.546 and 0 respectively. From Eqs. (1.1) and
(1.2), written in terms of force coefficients, and using Lilienthal’s nomenclature:
The ratio of lift-to-drag is
At α = 2o, from the Lilienthal Table, η = 0.489 and θ = 0.008
At α = 1o, η = 0.434 and θ = 0.016
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At α = 4o, η = 0.6 and θ = 0.007
So we have the following tabulation:
The Wright brothers chose a three-degree angle of attack for their design point
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