thermo model.c

gistfile1.txt

#include <cstdio>
// Internal integration step in seconds
#define STEP 0.01

// Calculate temperature after delta_t seconds of heating
// with power P in watts
double calculate_temp(double temp_start, double P, double delta_t)
{
  // Heat capacity, for aluminium = 920 J/K/Kg * (body mass, Kg)
  double C = 920 * 0.02;
  // Thermal resistance, K/W
  double Rt = 0.5;
  // Environment temperature, Celsius degree
  double t_env = 15;

  double tau = temp_start - t_env;
  
  for (double t = 0.0; t < delta_t; t += STEP)
  {
    double dtau_dt = (P * Rt - tau) / C / Rt;
    tau += dtau_dt * STEP;
  }
  
  return tau + t_env;
}

int main()
{
  // Initialize with environment temperature
  double temp = 15;
  printf("t=%f\n", temp);
  // Heating power
  double P = 200;
  for (int i = 0; i < 10; i++)
  {
    temp = calculate_temp(temp, P, 10.0);
    printf("t=%f\n", temp);
  }
  
  return 0;
}