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AIRFOIL: NACA 0021
DATA: Drag Coefficients
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ORIGINAL SOURCE: Sheldahl, R. E. and Klimas, P. C., Aerodynamic
Characteristics of Seven Airfoil Sections Through
180 Degrees Angle of Attack for Use in Aerodynamic
Analysis of Vertical Axis Wind Turbines, SAND80-2114,
March 1981, Sandia National Laboratories, Albuquerque,
New Mexico.

NOTES: The data herein were synthesised from a combination of
experimental results and computer calculations.

The original report contains data for lower Reynolds numbers
than contained herein, but there are some anomalies, in
particular with CL at small angles of attack.

Data extended to 360 degrees of attack and glaring anomalies
corrected by L. Lazauskas. All deviations from the original
are due to L. Lazauskas.

Please refer to the original report for more details.

------------------------------------------------------------------------ 
Drag Coefficient
-------------------------------- REYNOLDS NUMBER -----------------------
ALPHA 40000 80000 160000 360000 700000 1000000 2000000 5000000
------------------------------------------------------------------------
0 0.0232 0.0177 0.0139 0.0111 0.0094 0.0089 0.0082 0.0078
1 0.0233 0.0178 0.0140 0.0111 0.0094 0.0089 0.0083 0.0078
2 0.0237 0.0181 0.0143 0.0113 0.0096 0.0090 0.0084 0.0079
3 0.0243 0.0186 0.0148 0.0117 0.0098 0.0092 0.0086 0.0081
4 0.0253 0.0194 0.0155 0.0122 0.0103 0.0096 0.0089 0.0083
5 0.0264 0.0204 0.0163 0.0129 0.0109 0.0101 0.0092 0.0086
6 0.0279 0.0217 0.0174 0.0138 0.0117 0.0108 0.0098 0.0091
7 0.0297 0.0233 0.0187 0.0149 0.0126 0.0117 0.0105 0.0097
8 0.0319 0.0252 0.0204 0.0163 0.0138 0.0128 0.0114 0.0104
9 0.0343 0.0273 0.0222 0.0178 0.0152 0.0140 0.0124 0.0112
10 0.0620 0.0297 0.0243 0.0195 0.0166 0.0154 0.0135 0.0121
11 0.0925 0.0700 0.0266 0.0215 0.0184 0.0170 0.0148 0.0132
12 0.1230 0.1230 0.0292 0.0237 0.0202 0.0187 0.0162 0.0143
13 0.1405 0.1405 0.0860 0.0260 0.0223 0.0206 0.0179 0.0156
14 0.1580 0.1580 0.1580 0.0286 0.0244 0.0226 0.0196 0.0170
15 0.1770 0.1770 0.1770 0.1040 0.0269 0.0248 0.0215 0.0186
16 0.1960 0.1960 0.1960 0.1960 0.0295 0.0273 0.0236 0.0205
17 0.2170 0.2170 0.2170 0.2170 0.1250 0.0300 0.0260 0.0224
18 0.2380 0.2380 0.2380 0.2380 0.2380 0.1350 0.0285 0.0245
19 0.2600 0.2600 0.2600 0.2600 0.2600 0.2085 0.1450 0.0268
20 0.2820 0.2820 0.2820 0.2820 0.2820 0.2820 0.2820 0.0293
21 0.3055 0.3055 0.3055 0.3055 0.3055 0.3055 0.3055 0.1792
22 0.3290 0.3290 0.3290 0.3290 0.3290 0.3290 0.3290 0.3290
25 0.4050 0.4050 0.4050 0.4050 0.4050 0.4050 0.4050 0.4050
30 0.5700 0.5700 0.5700 0.5700 0.5700 0.5700 0.5700 0.5700
35 0.7450 0.7450 0.7450 0.7450 0.7450 0.7450 0.7450 0.7450
40 0.9200 0.9200 0.9200 0.9200 0.9200 0.9200 0.9200 0.9200
45 1.0750 1.0750 1.0750 1.0750 1.0750 1.0750 1.0750 1.0750
50 1.2150 1.2150 1.2150 1.2150 1.2150 1.2150 1.2150 1.2150
55 1.3450 1.3450 1.3450 1.3450 1.3450 1.3450 1.3450 1.3450
60 1.4700 1.4700 1.4700 1.4700 1.4700 1.4700 1.4700 1.4700
65 1.5750 1.5750 1.5750 1.5750 1.5750 1.5750 1.5750 1.5750
70 1.6650 1.6650 1.6650 1.6650 1.6650 1.6650 1.6650 1.6650
75 1.7350 1.7350 1.7350 1.7350 1.7350 1.7350 1.7350 1.7350
80 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800
85 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000
90 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000
95 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800
100 1.7500 1.7500 1.7500 1.7500 1.7500 1.7500 1.7500 1.7500
105 1.7000 1.7000 1.7000 1.7000 1.7000 1.7000 1.7000 1.7000
110 1.6350 1.6350 1.6350 1.6350 1.6350 1.6350 1.6350 1.6350
115 1.5550 1.5550 1.5550 1.5550 1.5550 1.5550 1.5550 1.5550
120 1.4650 1.4650 1.4650 1.4650 1.4650 1.4650 1.4650 1.4650
125 1.3500 1.3500 1.3500 1.3500 1.3500 1.3500 1.3500 1.3500
130 1.2250 1.2250 1.2250 1.2250 1.2250 1.2250 1.2250 1.2250
135 1.0850 1.0850 1.0850 1.0850 1.0850 1.0850 1.0850 1.0850
140 0.9250 0.9250 0.9250 0.9250 0.9250 0.9250 0.9250 0.9250
145 0.7550 0.7550 0.7550 0.7550 0.7550 0.7550 0.7550 0.7550
150 0.5750 0.5750 0.5750 0.5750 0.5750 0.5750 0.5750 0.5750
155 0.4200 0.4200 0.4200 0.4200 0.4200 0.4200 0.4200 0.4200
160 0.3200 0.3200 0.3200 0.3200 0.3200 0.3200 0.3200 0.3200
165 0.2300 0.2300 0.2300 0.2300 0.2300 0.2300 0.2300 0.2300
170 0.1400 0.1400 0.1400 0.1400 0.1400 0.1400 0.1400 0.1400
175 0.0550 0.0550 0.0550 0.0550 0.0550 0.0550 0.0550 0.0550
180 0.0250 0.0250 0.0250 0.0250 0.0250 0.0250 0.0250 0.0250
185 0.0550 0.0550 0.0550 0.0550 0.0550 0.0550 0.0550 0.0550
190 0.1400 0.1400 0.1400 0.1400 0.1400 0.1400 0.1400 0.1400
195 0.2300 0.2300 0.2300 0.2300 0.2300 0.2300 0.2300 0.2300
200 0.3200 0.3200 0.3200 0.3200 0.3200 0.3200 0.3200 0.3200
205 0.4200 0.4200 0.4200 0.4200 0.4200 0.4200 0.4200 0.4200
210 0.5750 0.5750 0.5750 0.5750 0.5750 0.5750 0.5750 0.5750
215 0.7550 0.7550 0.7550 0.7550 0.7550 0.7550 0.7550 0.7550
220 0.9250 0.9250 0.9250 0.9250 0.9250 0.9250 0.9250 0.9250
225 1.0850 1.0850 1.0850 1.0850 1.0850 1.0850 1.0850 1.0850
230 1.2250 1.2250 1.2250 1.2250 1.2250 1.2250 1.2250 1.2250
235 1.3500 1.3500 1.3500 1.3500 1.3500 1.3500 1.3500 1.3500
240 1.4650 1.4650 1.4650 1.4650 1.4650 1.4650 1.4650 1.4650
245 1.5550 1.5550 1.5550 1.5550 1.5550 1.5550 1.5550 1.5550
250 1.6350 1.6350 1.6350 1.6350 1.6350 1.6350 1.6350 1.6350
255 1.7000 1.7000 1.7000 1.7000 1.7000 1.7000 1.7000 1.7000
260 1.7500 1.7500 1.7500 1.7500 1.7500 1.7500 1.7500 1.7500
265 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800
270 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000
275 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000 1.8000
280 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800 1.7800
285 1.7350 1.7350 1.7350 1.7350 1.7350 1.7350 1.7350 1.7350
290 1.6650 1.6650 1.6650 1.6650 1.6650 1.6650 1.6650 1.6650
295 1.5750 1.5750 1.5750 1.5750 1.5750 1.5750 1.5750 1.5750
300 1.4700 1.4700 1.4700 1.4700 1.4700 1.4700 1.4700 1.4700
305 1.3450 1.3450 1.3450 1.3450 1.3450 1.3450 1.3450 1.3450
310 1.2150 1.2150 1.2150 1.2150 1.2150 1.2150 1.2150 1.2150
315 1.0750 1.0750 1.0750 1.0750 1.0750 1.0750 1.0750 1.0750
320 0.9200 0.9200 0.9200 0.9200 0.9200 0.9200 0.9200 0.9200
325 0.7450 0.7450 0.7450 0.7450 0.7450 0.7450 0.7450 0.7450
330 0.5700 0.5700 0.5700 0.5700 0.5700 0.5700 0.5700 0.5700
335 0.4050 0.4050 0.4050 0.4050 0.4050 0.4050 0.4050 0.4050
338 0.3290 0.3290 0.3290 0.3290 0.3290 0.3290 0.3290 0.3290
339 0.3055 0.3055 0.3055 0.3055 0.3055 0.3055 0.3055 0.1792
340 0.2820 0.2820 0.2820 0.2820 0.2820 0.2820 0.2820 0.0293
341 0.2600 0.2600 0.2600 0.2600 0.2600 0.2085 0.1450 0.0268
342 0.2380 0.2380 0.2380 0.2380 0.2380 0.1350 0.0285 0.0245
343 0.2170 0.2170 0.2170 0.2170 0.1250 0.0300 0.0260 0.0224
344 0.1960 0.1960 0.1960 0.1960 0.0295 0.0273 0.0236 0.0205
345 0.1770 0.1770 0.1770 0.1040 0.0269 0.0248 0.0215 0.0186
346 0.1580 0.1580 0.1580 0.0286 0.0244 0.0226 0.0196 0.0170
347 0.1405 0.1405 0.0860 0.0260 0.0223 0.0206 0.0179 0.0156
348 0.1230 0.1230 0.0292 0.0237 0.0202 0.0187 0.0162 0.0143
349 0.0925 0.0700 0.0266 0.0215 0.0184 0.0170 0.0148 0.0132
350 0.0620 0.0297 0.0243 0.0195 0.0166 0.0154 0.0135 0.0121
351 0.0343 0.0273 0.0222 0.0178 0.0152 0.0140 0.0124 0.0112
352 0.0319 0.0252 0.0204 0.0163 0.0138 0.0128 0.0114 0.0104
353 0.0297 0.0233 0.0187 0.0149 0.0126 0.0117 0.0105 0.0097
354 0.0279 0.0217 0.0174 0.0138 0.0117 0.0108 0.0098 0.0091
355 0.0264 0.0204 0.0163 0.0129 0.0109 0.0101 0.0092 0.0086
356 0.0253 0.0194 0.0155 0.0122 0.0103 0.0096 0.0089 0.0083
357 0.0243 0.0186 0.0148 0.0117 0.0098 0.0092 0.0086 0.0081
358 0.0237 0.0181 0.0143 0.0113 0.0096 0.0090 0.0084 0.0079
359 0.0233 0.0178 0.0140 0.0111 0.0094 0.0089 0.0083 0.0078
------------------------------------------------------------------------