src/FDM/LaRCsim/atmos_62.c

   1 /***************************************************************************
   2
   3     TITLE:                atmos_62
   4
   5 ----------------------------------------------------------------------------
   6
   7     FUNCTION:                1962 atmosphere table interpolation routine
   8
   9 ----------------------------------------------------------------------------
  10
  11     MODULE STATUS:        developmental
  12
  13 ----------------------------------------------------------------------------
  14
  15     GENEALOGY:        Created 920827 by Bruce Jackson as part of the C-castle
  16                 development effort.
  17
  18 ----------------------------------------------------------------------------
  19
  20     DESIGNED BY:        B. Jackson
  21
  22     CODED BY:                B. Jackson
  23
  24     MAINTAINED BY:        B. Jackson
  25
  26 ----------------------------------------------------------------------------
  27
  28     MODIFICATION HISTORY:
  29
  30         DATE        PURPOSE                                                        BY
  31         931220        Added ambient pressure and temperature as outputs.        EBJ
  32         940111        Changed includes from "ls_eom.h" to "ls_types.h" and
  33                 "ls_constants.h"; changed DATA to SCALAR types.                EBJ
  34
  35 ----------------------------------------------------------------------------
  36
  37     REFERENCES:
  38
  39     [ 1]        Hornbeck, Robert W.: "Numerical Methods", Prentice-Hall,
  40                 1975.  ISBN  0-13-626614-2
  41
  42 ----------------------------------------------------------------------------
  43
  44     CALLED BY:
  45
  46 ----------------------------------------------------------------------------
  47
  48     CALLS TO:
  49
  50 ----------------------------------------------------------------------------
  51
  52     INPUTS:
  53
  54 ----------------------------------------------------------------------------
  55
  56     OUTPUTS:
  57
  58 --------------------------------------------------------------------------*/
  59
  60 #include "ls_types.h"
  61 #include "ls_constants.h"
  62
  63 #include "atmos_62.h"
  64
  65 #include <math.h>
  66
  67 #define        alt_0        d_a_table[index  ][0]
  68 #define        alt_1        d_a_table[index+1][0]
  69 #define        den_0        d_a_table[index  ][1]
  70 #define den_1        d_a_table[index+1][1]
  71 #define        sps_0        d_a_table[index  ][2]
  72 #define        sps_1        d_a_table[index+1][2]
  73 #define gden_0        d_a_table[index  ][3]
  74 #define        gden_1        d_a_table[index+1][3]
  75 #define        gsps_0        d_a_table[index  ][4]
  76 #define gsps_1        d_a_table[index+1][4]
  77
  78 #define MAX_ALT_INDEX 121
  79 #define DELT_ALT 2000.
  80 #define HLEV 36089.
  81 #define TAMB0 518.7
  82 #define PAMB0 2113.8
  83 #define MAX_ALTITUDE 240000.
  84
  85 void ls_atmos( SCALAR altitude, SCALAR * sigma, SCALAR * v_sound,
  86                 SCALAR * t_amb, SCALAR * p_amb )
  87 {
  88
  89     int                index;
  90     SCALAR        daltp, daltn, daltp3, daltn3, density;
  91     SCALAR        t_amb_r, p_amb_r;
  92     SCALAR      tmp;
  93
  94     static SCALAR        d_a_table[MAX_ALT_INDEX][5] =
  95     {
  96         {      0.,         2.37701E-03,         1.11642E+03,         0.00000E+00,         0.00000E+00        },
  97         {   2000.,         2.24098E-03,         1.10872E+03,         1.92857E-12,        -1.75815E-08        },
  98         {   4000.,         2.11099E-03,         1.10097E+03,         1.34570E-12,        -1.21740E-08        },
  99         {   6000.,         1.98684E-03,         1.09315E+03,         1.44862E-12,        -1.47225E-08        },
 100         {   8000.,         1.86836E-03,         1.08529E+03,         1.36481E-12,        -1.44359E-08        },
 101         {  10000.,         1.75537E-03,         1.07736E+03,         1.32716E-12,        -1.45340E-08        },
 102         {  12000.,         1.64768E-03,         1.06938E+03,         1.27657E-12,        -1.44280E-08        },
 103         {  14000.,         1.54511E-03,         1.06133E+03,         1.24656E-12,        -1.62540E-08        },
 104         {  16000.,         1.44751E-03,         1.05323E+03,         1.19220E-12,        -1.50560E-08        },
 105         {  18000.,         1.35469E-03,         1.04506E+03,         1.15463E-12,        -1.65220E-08        },
 106         {  20000.,         1.26649E-03,         1.03683E+03,         1.11926E-12,        -1.63562E-08        },
 107         {  22000.,         1.18276E-03,         1.02853E+03,         1.07333E-12,        -1.70533E-08        },
 108         {  24000.,         1.10333E-03,         1.02016E+03,         1.03743E-12,        -1.59305E-08        },
 109         {  26000.,         1.02805E-03,         1.01173E+03,         1.00195E-12,        -2.27248E-08        },
 110         {  28000.,         9.56760E-04,         1.00322E+03,         9.39764E-13,         3.29851E-10        },
 111         {  30000.,         8.89320E-04,         9.94641E+02,         1.01399E-12,        -8.80946E-08        },
 112         {  32000.,         8.25570E-04,         9.85988E+02,         5.39268E-13,         2.41048E-07        },
 113         {  34000.,         7.65380E-04,         9.77258E+02,         2.16894E-12,        -9.91599E-07        },
 114         {  36000.,         7.08600E-04,         9.68448E+02,        -4.10001E-12,         3.60535E-06        },
 115         {  38000.,         6.44190E-04,         9.68053E+02,         2.78612E-12,        -8.07290E-07        },
 116         {  40000.,         5.85146E-04,         9.68053E+02,         1.00455E-12,         2.16313E-07        },
 117         {  42000.,         5.31517E-04,         9.68053E+02,         1.31819E-12,        -5.79609E-08        },
 118         {  44000.,         4.82801E-04,         9.68053E+02,         1.09217E-12,         1.55309E-08        },
 119         {  46000.,         4.38554E-04,         9.68053E+02,         1.01661E-12,        -4.16262E-09        },
 120         {  48000.,         3.98359E-04,         9.68053E+02,         9.19375E-13,         1.11961E-09        },
 121         {  50000.,         3.61850E-04,         9.68053E+02,         8.34886E-13,        -3.15801E-10        },
 122         {  52000.,         3.28686E-04,         9.68053E+02,         7.58579E-13,         1.43600E-10        },
 123         {  54000.,         2.98561E-04,         9.68053E+02,         6.89297E-13,        -2.58597E-10        },
 124         {  56000.,         2.71197E-04,         9.68053E+02,         6.25735E-13,         8.90788E-10        },
 125         {  58000.,         2.46341E-04,         9.68053E+02,         5.69765E-13,        -3.30456E-09        },
 126         {  60000.,         2.23765E-04,         9.68053E+02,         5.15206E-13,         1.23274E-08        },
 127         {  62000.,         2.03256E-04,         9.68053E+02,         4.69912E-13,        -4.60052E-08        },
 128         {  64000.,         1.84627E-04,         9.68053E+02,         4.25146E-13,         1.71693E-07        },
 129         {  66000.,         1.67616E-04,         9.68314E+02,         2.56502E-13,        -2.49268E-07        },
 130         {  68000.,         1.51855E-04,         9.68676E+02,         4.23844E-13,         9.76878E-07        },
 131         {  70000.,         1.37615E-04,         9.71034E+02,         3.29621E-13,        -6.64245E-07        },
 132         {  72000.,         1.24744E-04,         9.72390E+02,         3.11170E-13,         1.77102E-07        },
 133         {  74000.,         1.13107E-04,         9.73745E+02,         2.76697E-13,        -4.56627E-08        },
 134         {  76000.,         1.02584E-04,         9.75099E+02,         2.53043E-13,         4.04902E-09        },
 135         {  78000.,         9.30660E-05,         9.76450E+02,         2.18633E-13,         2.49667E-08        },
 136         {  80000.,         8.44530E-05,         9.77799E+02,         2.29927E-13,        -1.06916E-07        },
 137         {  82000.,         7.67140E-05,         9.78950E+02,         1.72660E-13,         1.05696E-07        },
 138         {  84000.,         6.97010E-05,         9.80290E+02,         1.68432E-13,        -3.23682E-08        },
 139         {  86000.,         6.33490E-05,         9.81620E+02,         1.45113E-13,         8.77690E-09        },
 140         {  88000.,         5.75880E-05,         9.82950E+02,         1.37617E-13,        -2.73938E-09        },
 141         {  90000.,         5.23700E-05,         9.84280E+02,         1.18918E-13,         2.18061E-09        },
 142         {  92000.,         4.76350E-05,         9.85610E+02,         1.11210E-13,        -5.98306E-09        },
 143         {  94000.,         4.33410E-05,         9.86930E+02,         9.77408E-14,         6.75162E-09        },
 144         {  96000.,         3.94430E-05,         9.88260E+02,         9.18264E-14,        -6.02343E-09        },
 145         {  98000.,         3.59080E-05,         9.89580E+02,         7.94534E-14,         2.34210E-09        },
 146         { 100000.,         3.26960E-05,         9.90900E+02,         7.48600E-14,        -3.34498E-09        },
 147         { 102000.,         2.97810E-05,         9.92210E+02,         6.66067E-14,        -3.96219E-09        },
 148         { 104000.,         2.71320E-05,         9.93530E+02,         5.77131E-14,         3.41937E-08        },
 149         { 106000.,         2.46980E-05,         9.95410E+02,         2.50410E-14,         7.07187E-07        },
 150         { 108000.,         2.24140E-05,         9.99070E+02,         6.71229E-14,        -1.92943E-07        },
 151         { 110000.,         2.03570E-05,         1.00272E+03,         4.69675E-14,         4.95832E-08        },
 152         { 112000.,         1.85010E-05,         1.00636E+03,         4.65069E-14,        -2.03903E-08        },
 153         { 114000.,         1.68270E-05,         1.00998E+03,         4.00047E-14,         1.97789E-09        },
 154         { 116000.,         1.53150E-05,         1.01359E+03,         3.64744E-14,        -2.52130E-09        },
 155         { 118000.,         1.39480E-05,         1.01719E+03,         3.15976E-14,        -6.89271E-09        },
 156         { 120000.,         1.27100E-05,         1.02077E+03,         3.06351E-14,         9.21465E-11        },
 157         { 122000.,         1.15920E-05,         1.02434E+03,         2.58618E-14,        -8.47587E-09        },
 158         { 124000.,         1.05790E-05,         1.02789E+03,         2.34176E-14,         3.81135E-09        },
 159         { 126000.,         9.66010E-06,         1.03144E+03,         2.16178E-14,        -6.76951E-09        },
 160         { 128000.,         8.82710E-06,         1.03497E+03,         1.89611E-14,        -6.73330E-09        },
 161         { 130000.,         8.07070E-06,         1.03848E+03,         1.74377E-14,         3.70270E-09        },
 162         { 132000.,         7.38380E-06,         1.04199E+03,         1.55382E-14,        -8.07752E-09        },
 163         { 134000.,         6.75940E-06,         1.04548E+03,         1.41595E-14,        -1.39263E-09        },
 164         { 136000.,         6.19160E-06,         1.04896E+03,         1.27239E-14,        -1.35196E-09        },
 165         { 138000.,         5.67490E-06,         1.05243E+03,         1.15951E-14,        -8.19953E-09        },
 166         { 140000.,         5.20450E-06,         1.05588E+03,         1.03459E-14,         4.15010E-09        },
 167         { 142000.,         4.77570E-06,         1.05933E+03,         9.42149E-15,        -8.40086E-09        },
 168         { 144000.,         4.38470E-06,         1.06276E+03,         8.66820E-15,        -5.46671E-10        },
 169         { 146000.,         4.02820E-06,         1.06618E+03,         7.65573E-15,        -4.41246E-09        },
 170         { 148000.,         3.70260E-06,         1.06959E+03,         7.05890E-15,         3.19650E-09        },
 171         { 150000.,         3.40520E-06,         1.07299E+03,         6.40867E-15,        -2.33736E-08        },
 172         { 152000.,         3.13330E-06,         1.07637E+03,         5.55641E-15,         6.02977E-08        },
 173         { 154000.,         2.88480E-06,         1.07975E+03,         6.46568E-15,        -2.17817E-07        },
 174         { 156000.,         2.66270E-06,         1.08202E+03,         8.18087E-15,        -8.54029E-07        },
 175         { 158000.,         2.46830E-06,         1.08202E+03,         2.36086E-15,         2.28931E-07        },
 176         { 160000.,         2.28810E-06,         1.08202E+03,         3.67571E-15,        -6.16972E-08        },
 177         { 162000.,         2.12120E-06,         1.08202E+03,         2.88632E-15,         1.78573E-08        },
 178         { 164000.,         1.96640E-06,         1.08202E+03,         2.92903E-15,        -9.73206E-09        },
 179         { 166000.,         1.82300E-06,         1.08202E+03,         2.49757E-15,         2.10709E-08        },
 180         { 168000.,         1.69000E-06,         1.08202E+03,         2.68069E-15,        -7.45517E-08        },
 181         { 170000.,         1.56680E-06,         1.08202E+03,         1.47966E-15,         2.77136E-07        },
 182         { 172000.,         1.45250E-06,         1.08202E+03,         4.75068E-15,        -1.03399E-06        },
 183         { 174000.,         1.35240E-06,         1.07963E+03,         8.17622E-16,         2.73830E-07        },
 184         { 176000.,         1.25880E-06,         1.07723E+03,         1.72883E-15,        -7.63301E-08        },
 185         { 178000.,         1.17130E-06,         1.07482E+03,         1.41704E-15,         1.64901E-08        },
 186         { 180000.,         1.08960E-06,         1.07240E+03,         1.30299E-15,        -4.63038E-09        },
 187         { 182000.,         1.01320E-06,         1.06998E+03,         1.32100E-15,         2.03140E-09        },
 188         { 184000.,         9.41950E-07,         1.06756E+03,         1.13799E-15,        -3.49522E-09        },
 189         { 186000.,         8.75370E-07,         1.06513E+03,         1.13202E-15,        -3.05052E-09        },
 190         { 188000.,         8.13260E-07,         1.06269E+03,         1.03892E-15,         6.97283E-10        },
 191         { 190000.,         7.55320E-07,         1.06025E+03,         9.67290E-16,         2.61383E-10        },
 192         { 192000.,         7.01260E-07,         1.05781E+03,         9.11920E-16,        -1.74281E-09        },
 193         { 194000.,         6.50850E-07,         1.05536E+03,         8.60032E-16,        -8.29013E-09        },
 194         { 196000.,         6.03870E-07,         1.05290E+03,         7.92951E-16,         1.99033E-08        },
 195         { 198000.,         5.60110E-07,         1.05044E+03,         7.98164E-16,        -7.13232E-08        },
 196         { 200000.,         5.19320E-07,         1.04798E+03,         4.69394E-16,         2.65389E-07        },
 197         { 202000.,         4.81340E-07,         1.04550E+03,         1.53926E-15,        -1.02023E-06        },
 198         { 204000.,         4.47960E-07,         1.04063E+03,         2.73571E-16,         2.30547E-07        },
 199         { 206000.,         4.16690E-07,         1.03565E+03,         5.31456E-16,        -6.69551E-08        },
 200         { 208000.,         3.87320E-07,         1.03065E+03,         4.50605E-16,         7.27308E-09        },
 201         { 210000.,         3.59790E-07,         1.02562E+03,         4.26126E-16,        -7.13720E-09        },
 202         { 212000.,         3.33970E-07,         1.02057E+03,         4.09893E-16,        -8.72426E-09        },
 203         { 214000.,         3.09780E-07,         1.01549E+03,         3.79301E-16,        -2.96576E-09        },
 204         { 216000.,         2.87120E-07,         1.01039E+03,         3.67902E-16,        -9.41272E-09        },
 205         { 218000.,         2.65920E-07,         1.00526E+03,         3.39092E-16,        -4.38337E-09        },
 206         { 220000.,         2.46090E-07,         1.00011E+03,         3.30732E-16,        -3.05378E-09        },
 207         { 222000.,         2.27570E-07,         9.94940E+02,         3.02981E-16,        -1.34015E-08        },
 208         { 224000.,         2.10270E-07,         9.89730E+02,         2.87343E-16,        -3.34027E-09        },
 209         { 226000.,         1.94120E-07,         9.84500E+02,         2.72646E-16,        -3.23743E-09        },
 210         { 228000.,         1.79060E-07,         9.79250E+02,         2.57074E-16,        -1.37100E-08        },
 211         { 230000.,         1.65030E-07,         9.73960E+02,         2.44060E-16,        -1.92258E-09        },
 212         { 232000.,         1.51970E-07,         9.68650E+02,         2.21687E-16,        -8.59969E-09        },
 213         { 234000.,         1.39810E-07,         9.63310E+02,         2.19191E-16,        -8.67865E-09        },
 214         { 236000.,         1.28510E-07,         9.57940E+02,         1.91549E-16,        -1.68569E-09        },
 215         { 238000.,         1.18020E-07,         9.52550E+02,         2.29613E-16,        -1.45786E-08        },
 216         { 240000.,         1.08270E-07,         9.47120E+02,         0.00000E+00,         0.00000E+00        }
 217     };
 218
 219     /* for purposes of doing the table lookup, force the incoming
 220        altitude to be >= 0 */
 221
 222     // printf("altitude = %.2f\n", altitude);
 223
 224     if ( altitude < 0.0 ) {
 225         altitude = 0.0;
 226     }
 227
 228     // printf("altitude = %.2f\n", altitude);
 229
 230     index = (int)( altitude / 2000 );
 231     if (index > (MAX_ALT_INDEX-2))
 232     {
 233      index = MAX_ALT_INDEX-2; /* limit maximum altitude */
 234      altitude = MAX_ALTITUDE;
 235     }
 236     if (index < 0) index = 0;
 237     daltp = alt_1 - altitude;
 238     daltp3 = daltp*daltp*daltp;
 239     daltn = altitude - alt_0;
 240     daltn3 = daltn*daltn*daltn;
 241
 242     density = (gden_0/6)*((daltp3/2000) - 2000*daltp)
 243                             + (gden_1/6)*((daltn3/2000) - 2000*daltn)
 244                             + den_0*daltp/2000 + den_1*daltn/2000;
 245
 246     *v_sound = (gsps_0/6)*((daltp3/2000) - 2000*daltp)
 247                             + (gsps_1/6)*((daltn3/2000) - 2000*daltn)
 248                             + sps_0*daltp/2000 + sps_1*daltn/2000;
 249
 250     *sigma = density/SEA_LEVEL_DENSITY;
 251
 252     if (altitude < HLEV)    /* BUG - these curve fits are only good to about 75000 ft */
 253       {
 254         t_amb_r = 1. - 6.875e-6*altitude;
 255         // printf("index = %d  t_amb_r = %.2f\n", index, t_amb_r);
 256         // p_amb_r = pow( t_amb_r, 5.256 );
 257         tmp = 5.256; // avoid a segfault (?)
 258         p_amb_r = pow( t_amb_r, tmp );
 259         // printf("p_amb_r = %.2f\n", p_amb_r);
 260       }
 261     else
 262       {
 263         t_amb_r = 0.751895;
 264         p_amb_r = 0.2234*exp( -4.806e-5 * (altitude - HLEV));
 265       }
 266
 267     *p_amb = p_amb_r * PAMB0;
 268     *t_amb = t_amb_r * TAMB0;
 269
 270 /* end of atmos_62 */
 271 }
 272 /**************************************************************************/