Exam 1 Definitions in
Aerodynamics ME3611 Aircraft
Design Spring 2014
Completely define the following terms. TYPE your answers!
1.
Zerolift drag coefficient In aerodynamics, the zerolift drag coefficient is a
dimensionless parameter which relates an ai
a
ao =
,u=o=t=1t = 2.643per radian = 0.0461 per degree
r , ao l+1.27G6
:
toAR
This gives
Cr
: 0.0461 (7.2) = 0.332.
Prandtl's lifting line rezults, which are not valid for low aspect ratio wings, gives a rezult that is
[(0.332 0.261yO.261] x 100 =27,Zo/
2.12 From Fig.2.5a, for the F102,
syo
=3
s
From Fig, 2.55, making the assumption that the F102 is comparable in size to the F100 and
F105, we have
Cr. = 0.0035
From Eq, (2.37),
co,o=
3.1 The inlet
(L* ) cr,=(3xo.oo3s)[email protected]
area is A
=
o d'
44=tr
Mass f
5.1 The thrust available, T,q, versus velocity is a constant value. Tlre thrust required, Ts" is
calculated as shown in Example 5.1 in the toct. The results are plotted below.
N
\
h,k
/oo
b
t$
200
.?nt
W (ft/so".)
/4oooff
2oo
cfw_
kr
/oo
tt
t;
(
;r
a
(
[r
Trrulwxw/s)
+
(w/s)&
Po
P Cop
,
(rn,
/wxw/s) + (w/tlJtr^"
/wz)#
Co,o
a)
Examining Eq. (2), the only term in which po appears is in the last term. As altitude increases,
p,
decreases, the
tt"L
term ,O
(p

increases, and because this term is
Po)'
Vn.* d
2.1 This is a problem involving dynamic similarity. To measure lift and drag coefficients in the
wind tunnel that pertain to those in actual flight, the Mach and Reynolds numbers must be the
same between flight and the wind tunnel. Let M and Re.denote th
Note the lar$e diffFerence between the two sets of rezults. This underscores the importance
of
taking into account the velocity variation of Te for a high bypass ratio turbofan in order to
obtain reatistic results. Recall that the worked examples in the
1.4
)
Q,
The lift at the quarter chord and I\4"/cfw_ must create the same force and moment effect as the lift
placed at the aerodynamic cnter md M,.o. I.e., if moments are taken about the leading edge,
the same value must hold whether the lift is placed a
Course Syllabus
ME 3611 Aircraft Design
Spring 2014
Instructor:
Text:
Dr. Jed E. Marquart, Professor of Mechanical Engineering
Office:
Biggs 138
Phone:
x2384
Email:
[email protected]
Office Hours: 910 AM (W,F), 1011 AM (M,W,F)
Aircraft Performance and
Definitions in Aerodynamics
ME3611 Aircraft Design
Spring 2014
Completely define the following terms. TYPE your answers!
Zerolift drag coefficient
Lift curve slope
Aerodynamic center
Center of pressure
Drag divergence Mach number
Airfoil camber
Airfoil c