yanni_userfuntion

function [therm_eff, net_power, bwr, Wt, Wc, Q_in, Q_out, pr1, pr2, pr3, pr4, h1, h2, h3, h4] = function_1(pr_in, t_in)
  pkg load io;
  data = xlsread('Air properties.xlsx');
  temp = data(:,1);
  h = data(:,2);
  pr = data(:,3);
  u = data(:,4);
  vr = data(:,5);
  s = data(:,6);

  % given data:
  p_ratio1 = 10;
  p_ratio2 = 0.1;
  t3 = 1400;
  flowrate = 5;

  % finding h1
  h1 = interp1(temp, h, t_in);

  % finding h2
  pr1 = interp1(temp, pr, t_in);
  pr2 = pr1 * p_ratio1;
  h2 = interp1(pr, h, pr2);

  % finding h3
  index2 = find(temp == t3);
  h3 = h(index2);

  % finding h4
  pr3 = pr(index2);
  pr4 = pr3 * p_ratio2;
  h4 = interp1(pr, h, pr4);

  % finding the thermal efficiency
  therm_eff = 0;
  for jj = 1:numel(h1)
    therm_eff(jj) = ((h3 - h4) - (h2(jj) - h1(jj)))/(h3 - h2(jj));
  end

  % back work ratio
  bwr = (h2 - h1)/(h3 - h4);

  % Net power in KW
  m_dot = 0;
  for jj = 1:numel(pr_in)
    m_dot(jj) = ((flowrate * (pr_in(jj)) * (10^3))/((8.314/28.97) * t_in(jj))) * (1/10^3);
    net_power(jj) = m_dot(jj) * ((h3 - h4) - (h2(jj) - h1(jj)));
  end

  Wt = m_dot * (h3 - h4);
  for jj = 1:numel(h1)
    Wc(jj) = m_dot(jj) * (h2(jj) - h1(jj));
    Q_in(jj) = m_dot(jj) * (h3 - h2(jj));
    Q_out(jj) = m_dot(jj) * (h4 - h1(jj));
  endfor
end