first time poster in this site.

I am trying to create a small program to make a graph of the Carnot cycle.

For isothermals I am simply trying to look for points where P*V would give the same Temperature so that I can display an isothermal curve.

However, I am having absolutely no luck with trying to plot an adiabatic curve. I know I want a steeper curve, but thats about it. Is there some sort of simpler way to draw out an adiabatic curve? Can I set any variable constant and try to draw the curve like an isotherm?

Any information is appreciated.

//i = x axis; j = y axis;
// for values 1 - 350
// plot y values from isothermal equation -- P*V = constant T
// j = k/i

 int k1 = 5000;
 //int k1 = 1500;
    //int k1 = 15000;
       //int k2 = 20000;
       int k2 = 15000;
       //int k2 = 30000;

  for( int i = 1; i < 350; i++) 
    int j1 = k1/i;
    int j2 = k2/i;
    //if(j1 < 350) 
        g.drawLine(i+50, j1+50, i+50, j1+50);
    //if(j2 < 350) 
        g.drawLine(i+50, j2+50, i+50, j2+50);


  //P*V^gamma = constant T
  double gamma = 1.67;

 for( int m = 1; m < 500; m++) 

   // int h1 = (int) (1400000/(Math.pow(m,1.97)));
   int h1 = (int) (1000000/(Math.pow(m,2)));
    //int h2 = (int) (3500000/(Math.pow(m,1.97)));
   int h2 = (int) (2400000/(Math.pow(m,2)));
    //if(j1 < 350) 
        g.drawLine(m+50, h1+50, m+50, h1+50);
    //if(j2 < 350) 
        g.drawLine(m+50, h2+50, m+50, h2+50);


test for drawing isotherms and adiabats


$PV^{\gamma}=Const$, where $\gamma = C_p/C_v$

  • $\begingroup$ Bear with me, but am I applying the exponent to (P*V) or only one of the two? so if i choose a monatomic and gamma is 1.67, do I write (x *y)^1.67 = Const? Also, since I have to tell the program to draw the points when the equation equals the constant in question, i'm having difficulty finding even a constant to attempt drawing. $\endgroup$ – lralvare Feb 26 '16 at 19:03
  • $\begingroup$ To get the constant, substitute the P and V at the end of the isothermal step. $\endgroup$ – Chet Miller Feb 26 '16 at 19:16
  • $\begingroup$ If I wanted to write P in terms of V; would I write it as something like... P = (Const/V)^(- gamma ) ? I have to write it this way in the program to make the plot points cleaner. $\endgroup$ – lralvare Feb 29 '16 at 9:31
  • $\begingroup$ made an attempt, though I'm sure I didn't do the correct equation with game since the adiabatic slopes taper off too quickly i think with greater X (volume). $\endgroup$ – lralvare Feb 29 '16 at 10:10
  • $\begingroup$ I have no idea what you are saying. $P=P_1(V_1/V)^{\gamma}$ $\endgroup$ – Chet Miller Feb 29 '16 at 12:18

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