report typos and errors to W.H.
Mason
Appendix D: Programs D-61
D.7 DesCam Users Manual
This program provides the camber line required to obtain the user input chord loading distribution for two-dimensional incompressible flow using thin airfoil theory. Lans quasi vortex lattice
method is used.
The program prompts the user for the name of the data set defining the chord load of interest.
The user is also prompted to enter the number of points at which a solution is required. Fifty is
enough for an extremely accurate answer. The maximum is 121.
INPUT DESCRIPTION
Card
Field
(all numeric input is in 2F10.5 format)
Variable
Description
Title
Up to 80 characters describing the data set/case (A79)
FNQ
number of x/c, Cp pairs describing design chord load
(the maximum is 101)
1
2
XQ
DC
the x/c input station for a given chord load
the design chord load at this x/c
************ CARD 3 is repeated FNQ times ************
Sample input:
NACA 6 series a = .4 mean line loading
3.0
0.0
1.42857
0.4
1.42857
1.0
0.00000
Sample output:
enter name of input data file
descam.inp
camber line design using quasi-vortex lattice method
case title:
NACA 6 series a = .4 mean line loading
design chord load
n
1
2
3
x/c
0.00000
0.40000
1.00000
CL =
1.0000
Delta Cp
1.4286
1.4286
0.0000
Cm =
0.0357
enter the number of points to be computed:
30.
Design angle of attack =
Friday, November 17, 1995
3.4113 degrees
D-62 Applied Computational Aerodynamics
i
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
x/c
0.00000
0.00274
0.01093
0.02447
0.04323
0.06699
0.09549
0.12843
0.16543
0.20611
0.25000
0.29663
0.34549
0.39604
0.44774
0.50000
0.55226
0.60396
0.65451
0.70337
0.75000
0.79389
0.83457
0.87157
0.90451
0.93301
0.95677
0.97553
0.98907
0.99726
1.00000
z/c
0.05961
0.06192
0.06636
0.07203
0.07837
0.08496
0.09144
0.09750
0.10287
0.10730
0.11054
0.11237
0.11252
0.11052
0.10600
0.09932
0.09115
0.08195
0.07213
0.06208
0.05213
0.04259
0.03370
0.02569
0.01868
0.01279
0.00804
0.00443
0.00193
0.00047
0.00000
dz/dx
1.07277
0.61767
0.46497
0.37212
0.30444
0.25031
0.20439
0.16374
0.12646
0.09118
0.05671
0.02174
-0.01581
-0.06321
-0.11174
-0.14406
-0.16858
-0.18725
-0.20102
-0.21052
-0.21624
-0.21864
-0.21813
-0.21515
-0.21016
-0.20365
-0.19616
-0.18831
-0.18084
-0.17476
-0.17179
(z-z0)/c
0.000000
0.002478
0.007398
0.013875
0.021338
0.029344
0.037524
0.045550
0.053125
0.059976
0.065838
0.070447
0.073504
0.074520
0.073080
0.069511
0.064456
0.058341
0.051540
0.044399
0.037228
0.030300
0.023843
0.018032
0.012991
0.008792
0.005459
0.002972
0.001279
0.000311
0.000000
STOP
Note: The data in the z/c column is the surface shape including both angle of attack and camber.
This means that the surface starts at positive (normally) value of z. To obtain a traditional camber
line distribution that starts and stops at z = 0, the shape is rotated down by the value of the design angle of attack. The result is given in the column listed as (z-z0)/c, which is now a pure
camber surface, with the camber at both the leading and trailing edges equal to zero. The equations are given in Section 6.11 of the text. In particular, see Eq. (6-109) for the details of the rotation.
Friday, November 17, 1995