src/FDM/LaRCsim/c172_engine.c

   1 /***************************************************************************
   2
   3         TITLE:          engine.c
   4
   5 ----------------------------------------------------------------------------
   6
   7         FUNCTION:       dummy engine routine
   8
   9 ----------------------------------------------------------------------------
  10
  11         MODULE STATUS:  incomplete
  12
  13 ----------------------------------------------------------------------------
  14
  15         GENEALOGY:      This is a renamed navion_engine.c originall written by E. Bruce
  16                                 Jackson
  17
  18
  19 ----------------------------------------------------------------------------
  20
  21         DESIGNED BY:    designer
  22
  23         CODED BY:       programmer
  24
  25         MAINTAINED BY:  maintainer
  26
  27 ----------------------------------------------------------------------------
  28
  29         MODIFICATION HISTORY:
  30
  31         DATE    PURPOSE                                         BY
  32
  33         CURRENT RCS HEADER INFO:
  34
  35 $Header$
  36
  37  * Revision 1.1  92/12/30  13:21:46  bjax
  38  * Initial revision
  39  *
  40
  41 ----------------------------------------------------------------------------
  42
  43         REFERENCES:
  44
  45 ----------------------------------------------------------------------------
  46
  47         CALLED BY:      ls_model();
  48
  49 ----------------------------------------------------------------------------
  50
  51         CALLS TO:       none
  52
  53 ----------------------------------------------------------------------------
  54
  55         INPUTS:
  56
  57 ----------------------------------------------------------------------------
  58
  59         OUTPUTS:
  60
  61 --------------------------------------------------------------------------*/
  62 #include <math.h>
  63 #include "ls_types.h"
  64 #include "ls_constants.h"
  65 #include "ls_generic.h"
  66 #include "ls_sim_control.h"
  67 #include "ls_cockpit.h"
  68 #include "c172_aero.h"
  69
  70 extern SIM_CONTROL      sim_control_;
  71
  72 void c172_engine( SCALAR dt, int init ) {
  73
  74     float v,h,pa;
  75     float bhp=160;
  76
  77     Throttle[3] = Throttle_pct;
  78
  79
  80     if ( ! Use_External_Engine ) {
  81         /* do a crude engine power calc based on throttle position */
  82         v=V_rel_wind;
  83         h=Altitude;
  84         if(V_rel_wind < 10)
  85             v=10;
  86         if(Altitude < 0)
  87             h=0;
  88         pa=(0.00144*v + 0.546)*(1 - 1.6E-5*h)*bhp;
  89         if(pa < 0)
  90             pa=0;
  91
  92         F_X_engine = Throttle[3]*(pa*550)/v;
  93     } else {
  94         /* accept external settings */
  95     }
  96
  97     /* printf("F_X_engine = %.3f\n", F_X_engine); */
  98
  99     M_m_engine = F_X_engine*0.734*cbar;
 100     /* 0.734 - estimated (WAGged) location of thrust line in the z-axis*/
 101
 102 }
 103
 104