Attachment 'hc04.c'

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   1 // hc04.c
   2 // compute heating and cooling 
   3 //
   4 // gcc -o hc04 hc04.c -lm
   5 
   6 #define  NAME   "hc04"
   7 #define  CMD    "hc"
   8 
   9 #define  RATE       12   //          Flash frame rate ( 60x )
  10 #define  TIME     3600   //          Total time
  11 #define  NPLOT     720   //          Number of plots
  12 #define  NCOMP      70   //          Computation passes per plot
  13 #define  PPLOT    2400   //          Plot width (may be ugly!)
  14 #define  OPLOT    -200   //
  15 
  16 #define  TEMP0   315.0   // K        Starting temperature
  17 #define  TEMPA   250.0   // K        Ambient temperature
  18 #define  PV    10800.0   // m/s      Payload maximum velocity
  19 #define  PA       30.0   // m/s2     Payload acceleration
  20 #define  PT      360.0   // s        Payload acceleration time
  21 #define  PM     5000.0   // kg       Payload mass
  22 #define  PL     1944.0   // km       Payload acceleration distance
  23 
  24 #define  PS       24.0   // s        Payload spacing in time
  25 #define  PN         15   //          Number of computed payloads
  26 
  27 #define  RL       5180   // km       Rotor Length
  28 #define  RM        3.0   // kg/m     Rotor mass/length
  29 #define  RR      0.025   // m        Rotor radius in meters
  30 #define  RV    14000.0   // m/s      Rotor velocity
  31 
  32 #define  EM        0.8   //          Emissivity
  33 #define  SB    5.67E-8   // W/m2K4   Blackbody radiation
  34 #define  HC        600   // J/kg-K   Rotor heat capacity
  35 #define  PI 3.14159265 
  36 
  37 #include <math.h>
  38 #include <string.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 
  42 double  rtemp[RL]                  ; // rotor temperature K
  43 
  44 // modulus function
  45 int rmax = RL * ( 500000000 / RL ) ; // large offset multiple of RL
  46 int rmod( int arg ) { return ( ( rmax + arg ) % RL ) ; }
  47 
  48 //-----------------------------------------------------------------
  49 int main() {
  50 
  51    FILE    *datfile                     ; //
  52    char    rmmkdir[200]                 ; //
  53    char    png2swf[200]                 ; //
  54    char    gnuplot[200]                 ; //
  55    char    filename[80]                 ; //
  56 
  57    double  ptime                        ; // acceleration time of payload
  58    double  vp                           ; // velocity of payload
  59    double  xp                           ; // position of payload
  60 
  61    int     ipoint                       ; // point index for plotting, cooling
  62    int     index = 0                    ; // movement of rotor since t0
  63    int     iplot                        ; // plot number
  64    int     icomp                        ; // computation index
  65    int     ipay                         ; // payload index
  66    double  rtp                          ; // temporary rtemp
  67    double  time                         ; // simulating time
  68    double  tdelta = 1000.0/RV           ; // timestep in seconds
  69    double  xpoint                       ; //
  70 
  71    double  dtp = tdelta                   // payload heating factor 
  72                * PA * PM                  // payload force
  73                * 0.001                    // kilometer of mass
  74                / ( RM * HC )            ; // rotor heat capacity  J/K
  75 
  76    double  heat                         ; // added heat
  77    int     ip                           ; // integer position of payload
  78    int     ip0                          ; // payload position 0,  rotor-coords
  79    int     ip1                          ; // payload position 1,  rotor-coords
  80    double  xpi                          ; // integer part of payload position
  81    double  xpf                          ; // fractional part of position
  82 
  83    double  dt0 = tdelta                   // rotor cooling factor
  84                * EM * SB                  // blackbody radiation
  85                * 2.0 * PI * RR            // surface area
  86                / ( RM * HC )            ; // rotor heat capacity  J/K
  87 
  88    double  dt1 = dt0                      // rotor ambient 
  89                * TEMPA*TEMPA              //
  90                * TEMPA*TEMPA            ; // 
  91 
  92    // --------------------------------------------------------------------
  93 
  94    printf ( "tdelta = %14.4e\n", tdelta );
  95    printf ( "dt0    = %14.4e\n", dt0    );
  96    printf ( "dt1    = %14.4e\n", dt1    );
  97    printf ( "dtp    = %14.4e\n", dtp    );
  98 
  99    sprintf( rmmkdir, "rm -rf %sdir ; mkdir %sdir", NAME, NAME );
 100    system( rmmkdir )           ; // make directory
 101 
 102    // initialize
 103    for( ipoint=0 ; ipoint < RL ; ipoint++ ) { rtemp[ipoint] = TEMP0 ; }
 104 
 105    // plot loop
 106    for( iplot=0 ; iplot < NPLOT ; iplot++ ) { 
 107 
 108       printf( "plot %4d\r", iplot ); fflush( stdout );
 109 
 110       // compute loop per plot
 111       for( icomp=0 ; icomp < NCOMP ; icomp++ ) {
 112 
 113          index = iplot*NCOMP + icomp ;
 114          time  = tdelta * ((double) index );
 115 
 116          //  cooling
 117          for( ipoint=0 ; ipoint < RL ; ipoint++ ) {
 118             rtp  = rtemp[ ipoint ] ;
 119             rtp *= rtp ;
 120             rtemp[ ipoint ] -= dt0*rtp*rtp - dt1 ;
 121          }
 122 
 123          // heating by payloads - start a little later
 124          for( ipay = 1 ; ipay <= PN ; ipay++ ) {
 125             ptime = time - PS * ((double)ipay) ;
 126             if( ( ptime >= 0.0 ) && ( ptime <= PT ) ) {
 127 
 128                vp   = PA * ptime           ;
 129                heat = dtp * ( RV - vp )    ;
 130 
 131                xp   = 0.0005 * vp * ptime  ;
 132                xpi  = floor( xp )          ;
 133                ip   = (int) xpi            ;
 134                xpf  = xp-xpi               ;
 135                ip0  = rmod( ip   - index ) ;
 136                ip1  = rmod( ip+1 - index ) ;
 137 
 138                rtemp[ ip0 ] += heat*(1.0-xpf) ;
 139                rtemp[ ip1 ] += heat*(    xpf) ;
 140             }
 141          }
 142       } // end of icomp compute loop 
 143 
 144       index   = (iplot+1)*NCOMP ;
 145       datfile = fopen( "tmp.dat", "wb" );
 146 
 147       for( ipoint = 0 ; ipoint < PPLOT ; ipoint++ ) {
 148          xpoint = (double)( OPLOT+ipoint) ;  // starts before 0
 149          ip     = rmod( OPLOT+ipoint-index );
 150          fprintf( datfile, "%16.4f%16.4f\n", xpoint, rtemp[ ip ] ) ;
 151       }
 152       fclose( datfile );
 153 
 154       sprintf( gnuplot, "/usr/local/bin/gp %s.cmd", CMD );
 155       system( gnuplot );
 156 
 157       sprintf( filename, "%sdir/b%04d.png", NAME, iplot );
 158       rename( "tmp.png", filename );
 159    }
 160 
 161    // make flash video
 162    sprintf( png2swf, "png2swf -o %s.swf -r%3d %sdir/*.png", NAME, RATE, NAME );
 163    system( png2swf );
 164 
 165    return(0);
 166 }

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  • [get | view] (2009-07-21 16:36:09, 1.7 KB) [[attachment:hc.cmd]]
  • [get | view] (2009-07-21 16:33:58, 6.0 KB) [[attachment:hc03.c]]
  • [get | view] (2009-07-21 16:34:18, 1.7 KB) [[attachment:hc03.cmd]]
  • [get | view] (2021-06-20 02:58:20, 1338.6 KB) [[attachment:hc03.png]]
  • [get | view] (2009-07-21 16:35:23, 6.1 KB) [[attachment:hc04.c]]
  • [get | view] (2021-06-20 02:58:32, 608.2 KB) [[attachment:hc04.png]]
  • [get | view] (2009-07-21 16:36:25, 6.1 KB) [[attachment:hc05.c]]
  • [get | view] (2021-06-20 02:58:43, 490.5 KB) [[attachment:hc05.png]]
  • [get | view] (2009-08-12 16:04:40, 6.1 KB) [[attachment:hc06.c]]
  • [get | view] (2021-06-20 02:58:53, 570.7 KB) [[attachment:hc06.png]]
  • [get | view] (2009-08-12 16:12:49, 14.4 KB) [[attachment:hc08t.c]]
  • [get | view] (2009-08-12 16:13:14, 1.7 KB) [[attachment:hc08t.cmd]]
  • [get | view] (2021-06-20 01:05:31, 1896.1 KB) [[attachment:hc08t.png]]
  • [get | view] (2009-08-12 16:17:29, 30.4 KB) [[attachment:heat03.png]]
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