001/* 002* NACA66Series -- An arbitrary NACA 66 series airfoil. 003* 004* Copyright (C) 2010-2025, by Joseph A. Huwaldt. All rights reserved. 005* 006* This library is free software; you can redistribute it and/or 007* modify it under the terms of the GNU Lesser General Public 008* License as published by the Free Software Foundation; either 009* version 2.1 of the License, or (at your option) any later version. 010* 011* This library is distributed in the hope that it will be useful, 012* but WITHOUT ANY WARRANTY; without even the implied warranty of 013* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014* Lesser General Public License for more details. 015* 016* You should have received a copy of the GNU Lesser General Public License 017* along with this program; if not, write to the Free Software 018* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 019* Or visit: http://www.gnu.org/licenses/lgpl.html 020*/ 021package jahuwaldt.aero.airfoils; 022 023import java.util.List; 024import java.awt.geom.Point2D; 025import java.text.DecimalFormat; 026import java.text.NumberFormat; 027 028 029/** 030* <p> This class represents an arbitrary NACA 66 series 031* airfoil section such as a NACA 66-020 airfoil. 032* </p> 033* 034* <p> Ported from FORTRAN "NACA6.FOR" to Java by: 035* Joseph A. Huwaldt, June 4, 2010 </p> 036* 037* <p> Original FORTRAN "NACA4" code had the following note: </p> 038* 039* <pre> 040* AUTHORS - Charles L.Ladson and Cuyler W. Brooks, NASA Langley 041* Liam Hardy, NASA Ames 042* Ralph Carmichael, Public Domain Aeronautical Software 043* Last FORTRAN version: 23Nov96 2.0 RLC 044* 045* NOTES - This program has also been known as LADSON and SIXSERIES and 046* as SIXSERIE on systems with a 8-letter name limit. 047* REFERENCES- NASA Technical Memorandum TM X-3069 (September, 1974), 048* by Charles L. Ladson and Cuyler W. Brooks, Jr., NASA Langley Research Center. 049* 050* "Theory of Wing Sections", by Ira Abbott and Albert Von Doenhoff. 051* </pre> 052* 053* <p> Modified by: Joseph A. Huwaldt </p> 054* 055* @author Joseph A. Huwaldt Date: June 5, 2010 056* @version February 22, 2025 057*/ 058public class NACA66Series extends NACA6Series { 059 060 //----------------------------------------------------------------------------------- 061 062 /** 063 * Create a NACA 66 series airfoil with the specified parameters. 064 * 065 * @param CLi Design lift coefficient (e.g.: 66-206 has CLi = 0.2). 066 * @param thickness The thickness to chord ratio (e.g.: 0.20 == 20% t/c). 067 * @param length The chord length. 068 */ 069 public NACA66Series(double CLi, double thickness, double length) { 070 super(CLi, thickness, length); 071 } 072 073 /** 074 * Returns a String that represents the profile type of this airfoil. 075 */ 076 @Override 077 public String getProfile() { 078 return "66"; 079 } 080 081 // Phi & eps vectors for 66 series airfoil. 082 private static final double[] philde = { 083 0.,.0157,.03139, 084 .04709,.06279,.07849,.0942,.10991, 085 .12563,.14135,.15708,.17277, 086 .18847,.20417,.21987,.23559,.2513, 087 .26701,.28273,.29844,.31416, 088 .32987,.34558,.36129,.37699,.3927, 089 .40841,.42411,.43982,.45553, 090 .47124,.48694,.50265,.51836,.53406, 091 .54977,.56548,.58119,.5969, 092 .61261,.62832,.64403,.65974,.67545, 093 .69116,.70686,.72257,.73828, 094 .75399,.76969,.7854,.80111,.81682, 095 .83253,.84824,.86394,.87965, 096 .89536,.91107,.92677,.94248,.95819, 097 .9739,.98961,1.00532,1.02103, 098 1.03673,1.05244,1.06815,1.08385, 099 1.09956,1.11527,1.13098,1.14669, 100 1.1624,1.17811,1.19381,1.20952, 101 1.22523,1.24093,1.25664,1.27235, 102 1.28806,1.30377,1.31948,1.33519, 103 1.3509,1.3666,1.38231,1.39802,1.41372, 104 1.42943,1.44514,1.46085,1.47656, 105 1.49227,1.50798,1.52368,1.53939, 106 1.5551,1.5708,1.58651,1.60223,1.61794, 107 1.63365,1.64936,1.66507,1.68077, 108 1.69648,1.71218,1.72788,1.74359, 109 1.75931,1.77501,1.79072,1.80643, 110 1.82214,1.83784,1.85355,1.86925, 111 1.88496,1.90066,1.91636,1.93206, 112 1.94776,1.96347,1.97918,1.99489, 113 2.0106,2.02632,2.04204,2.05773, 114 2.07343,2.08913,2.10484,2.12054, 115 2.13625,2.15196,2.16768,2.18339, 116 2.19911,2.21482,2.23052,2.24623, 117 2.26194,2.27765,2.29336,2.30906, 118 2.32477,2.34048,2.35619,2.37191, 119 2.38762,2.40333,2.41905,2.43476, 120 2.45046,2.46617,2.48187,2.49757, 121 2.51327,2.529,2.54473,2.56045,2.57616, 122 2.59188,2.60758,2.62328,2.63898, 123 2.65467,2.67035,2.68609,2.70183, 124 2.71756,2.73328,2.74899,2.76469, 125 2.78039,2.79608,2.81176,2.82743, 126 2.84317,2.85891,2.87463,2.89035, 127 2.90606,2.92176,2.93746,2.95315, 128 2.96883,2.98451,3.00023,3.01595, 129 3.03167,3.04738,3.06309,3.07879, 130 3.09449,3.11019,3.12589,3.14159 }; 131 132 private static final double[] epslde = { 133 0.,.00145,.0029, 134 .00433,.00574,.00712,.00847,.00978, 135 .01105,.01225,.0134,.01447, 136 .01547,.01638,.01719,.01789,.01847, 137 .01893,.01924,.0194,.0194, 138 .01924,.01893,.0185,.01799,.01741, 139 .01679,.01616,.01556,.01499, 140 .0145,.0141,.01379,.01356,.0134, 141 .01331,.01327,.01328,.01333, 142 .0134,.0135,.01361,.01373,.01387, 143 .01402,.01419,.01438,.01458, 144 .0148,.01504,.0153,.01558,.01588, 145 .0162,.01654,.01689,.01726, 146 .01765,.01805,.01847,.0189,.01934, 147 .0198,.02026,.02074,.02124, 148 .02174,.02226,.02279,.02334,.0239, 149 .02447,.02506,.02566,.02627, 150 .0269,.02754,.02819,.02885,.02952, 151 .0302,.03089,.0316,.03231, 152 .03304,.03378,.03453,.0353,.03608, 153 .03688,.0377,.03853,.03938, 154 .04025,.04113,.04202,.04293,.04386, 155 .04479,.04574,.0467,.04767, 156 .04866,.04966,.05067,.05171,.05277, 157 .05386,.05498,.05612,.0573, 158 .05851,.05976,.06103,.06231,.06362, 159 .06493,.06625,.06758,.06889, 160 .0702,.07149,.07277,.07402,.07524, 161 .07644,.0776,.07872,.07979, 162 .08082,.0818,.08272,.08359,.0844, 163 .08515,.08585,.08649,.08708, 164 .08761,.08808,.0885,.08886,.08916, 165 .08941,.08959,.08972,.08978, 166 .08978,.08972,.08959,.0894,.08914, 167 .08882,.08843,.08797,.08745, 168 .08687,.08622,.08551,.08474,.0839, 169 .083,.08203,.08101,.07991, 170 .07875,.07752,.07622,.07485,.07341, 171 .0719,.07031,.06864,.06691, 172 .0651,.06323,.06129,.05928,.05722, 173 .05509,.0529,.05064,.04833, 174 .04596,.04354,.04108,.03856,.03601, 175 .03341,.03077,.0281,.02539, 176 .02264,.01987,.01707,.01426,.01143, 177 .00858,.00573,.00287,0. }; 178 179 /** 180 * Fill in phi, eps vectors for 66 series airfoil. 181 * 182 * @param phi An existing array with 201 elements to be filled in 183 * by this method. 184 * @param eps An existing array with 201 elements to be filled in 185 * by this method. 186 */ 187 @Override 188 protected final void phep(double[] phi, double[] eps) { 189 System.arraycopy(philde, 0, phi, 0, 201); 190 System.arraycopy(epslde, 0, eps, 0, 201); 191 } 192 193 194 // Phi & eps vectors for 66 series airfoil. 195 private static final double[] philds = { 196 0.,.01573,.03145, 197 .04718,.0629,.07862,.09433,.11003, 198 .12572,.14141,.15708,.1728, 199 .18851,.20422,.21992,.23562,.25131, 200 .26701,.28272,.29844,.31416, 201 .32984,.34552,.36122,.37693,.39264, 202 .40835,.42407,.4398,.45552, 203 .47124,.48696,.50267,.51838,.53409, 204 .54979,.5655,.58121,.59691, 205 .61262,.62832,.64403,.65973,.67544, 206 .69115,.70686,.72257,.73827, 207 .75398,.76969,.7854,.80111,.81682, 208 .83252,.84823,.86394,.87965, 209 .89536,.91106,.92677,.94248,.95819, 210 .9739,.9896,1.00531,1.02102, 211 1.03673,1.05244,1.06814,1.08385, 212 1.09956,1.11527,1.13098,1.14668, 213 1.16239,1.1781,1.19381,1.20952, 214 1.22522,1.24093,1.25664,1.27235, 215 1.28806,1.30376,1.31947,1.33518, 216 1.35089,1.3666,1.3823,1.39801,1.41372, 217 1.42943,1.44514,1.46085,1.47655, 218 1.49226,1.50797,1.52368,1.53939, 219 1.55509,1.5708,1.58651,1.60222, 220 1.61793,1.63364,1.64934,1.66505, 221 1.68076,1.69647,1.71217,1.72788, 222 1.7436,1.75932,1.77504,1.79075, 223 1.80647,1.82217,1.83788,1.85358, 224 1.86927,1.88496,1.9007,1.91642, 225 1.93214,1.94786,1.96357,1.97927, 226 1.99497,2.01067,2.02636,2.04204, 227 2.05777,2.07349,2.0892,2.10492, 228 2.12062,2.13633,2.15203,2.16773, 229 2.18342,2.19911,2.21483,2.23055, 230 2.24626,2.26197,2.27768,2.29338, 231 2.30909,2.32479,2.34049,2.35619, 232 2.3719,2.38761,2.40331,2.41902, 233 2.43473,2.45043,2.46614,2.48185, 234 2.49756,2.51327,2.52897,2.54467, 235 2.56037,2.57607,2.59178,2.60749, 236 2.6232,2.63891,2.65463,2.67035, 237 2.68604,2.70173,2.71742,2.73312, 238 2.74882,2.76453,2.78025,2.79597, 239 2.8117,2.82743,2.84311,2.8588,2.87449, 240 2.89019,2.9059,2.92161,2.93733, 241 2.95305,2.96878,2.98451,3.0002,3.0159, 242 3.0316,3.04731,3.06302,3.07873, 243 3.09444,3.11016,3.12587,3.14159 }; 244 245 private static final double[] psilds = { 246 .16457,.16455,.16449, 247 .16437,.16416,.16386,.16345, 248 .16292,.16223,.16139,.16037,.15916, 249 .15779,.15631,.15475,.15316, 250 .15157,.15002,.14856,.14722,.14604, 251 .14506,.14427,.14364,.14316, 252 .14281,.14257,.14242,.14235,.14233, 253 .14236,.14241,.14248,.14257, 254 .14267,.1428,.14294,.1431,.14327, 255 .14346,.14366,.14387,.1441, 256 .14433,.14457,.14481,.14506,.1453, 257 .14554,.14578,.14601,.14623, 258 .14645,.14665,.14685,.14704,.14722, 259 .1474,.14757,.14774,.1479, 260 .14806,.14821,.14835,.14849,.14862, 261 .14875,.14886,.14897,.14908, 262 .14917,.14925,.14933,.1494,.14945, 263 .1495,.14954,.14957,.14959, 264 .14961,.14961,.1496,.14959,.14956, 265 .14953,.14948,.14943,.14936, 266 .14928,.14918,.14908,.14896,.14883, 267 .14869,.14853,.14835,.14816, 268 .14796,.14774,.1475,.14725,.14698, 269 .14669,.14638,.14606,.14571, 270 .14533,.14494,.14452,.14407,.1436, 271 .1431,.14256,.14198,.14135, 272 .14067,.13992,.1391,.1382,.13722, 273 .13615,.13498,.13371,.13236, 274 .13093,.12942,.12786,.12623,.12456, 275 .12284,.12108,.11929,.11746, 276 .11561,.11373,.11182,.10987,.1079, 277 .1059,.10386,.1018,.0997,.09758, 278 .09542,.09325,.09106,.08885, 279 .08662,.08439,.08214,.07989,.07763, 280 .07537,.07311,.07085,.06859, 281 .06633,.06407,.06182,.05957,.05733, 282 .0551,.05287,.05066,.04846, 283 .04627,.04411,.04196,.03983,.03773, 284 .03566,.03362,.03161,.02964, 285 .0277,.0258,.02395,.02215,.02039, 286 .01869,.01705,.01547,.01396, 287 .0125,.01112,.00981,.00857,.0074, 288 .00631,.00531,.00439,.00356, 289 .00281,.00216,.00159,.0011,7.1e-4, 290 4e-4,1.8e-4,4e-5,0. }; 291 292 /** 293 * Fill in the psi vector for a 66 series airfoil. 294 * 295 * @param phi An array filled in by phep(). 296 * @param psi An existing array with 201 elements to be filled in 297 * by this method. 298 */ 299 @Override 300 protected final void phps(double[] phi, double[] psi) { 301 double[] bb = new double[201]; 302 double[] cc = new double[201]; 303 double[] dd = new double[201]; 304 spline(201, philds, psilds, bb, cc, dd); 305 for (int i=0; i < 201; ++i) { 306 psi[i] = seval(201, phi[i], philds, psilds, bb, cc, dd); 307 } 308 } 309 310 /** 311 * Simple method to test this class. 312 * 313 * @param args the command-line arguments 314 */ 315 public static void main(String[] args) { 316 317 DecimalFormat nf = (DecimalFormat)NumberFormat.getInstance(); 318 nf.setMaximumFractionDigits(5); 319 nf.setMinimumFractionDigits(5); 320 321 System.out.println("Start NACA66Series..."); 322 323 System.out.println("Creating a NACA 66-212 airfoil..."); 324 Airfoil af = new NACA66Series(0.2, 0.12, 1); 325 326 System.out.println("Airfoil = " + af.toString()); 327 328 // Output the upper surface of the airfoil. 329 List<Point2D> upper = af.getUpper(); 330 List<Double> ypArr = af.getUpperYp(); 331 System.out.println("upper.size() = " + upper.size() + ", ypArr.size() = " + ypArr.size()); 332 333 System.out.println(" X \t Y \t dy/dx"); 334 int length = upper.size(); 335 for (int i=0; i < length; ++i) { 336 Point2D o = upper.get(i); 337 System.out.println(" " + nf.format(o.getX()) + "\t" + nf.format(o.getY()) + 338 "\t" + nf.format(ypArr.get(i))); 339 } 340 341 System.out.println("# ordinates = " + length); 342 System.out.println("Done!"); 343 } 344} 345 346