otto cycle

clear all

close all

clc

%inputs

gamma=1.4

t3=2500

% state variable at point1

p1=101325

t1=500

%engine geometry parameter

bore=0.1

stroke=0.1

con_rod=0.15

cr=12

a=stroke/2

R=con_rod/a

%calculating swept volume

v_swept=pi/4*bore^2*stroke;

v_clearence=v_swept/cr-1

v1=v_swept+v_clearence

v2=v_clearence

% state variable at point 2

p2=p1*cr^gamma

t2=p2*v2*t1/p1*v1

%state variable at point 3
v3=v2

p3=p2*t3/t2

%state variable at point 4

v4=v1

p4=p3*(v3/v4)^gamma

%inputs 2

theta= linspace(0,180,100)

term1=0.5*(cr-1)

term2= R+1-cosd(theta);

term3=(R^2-sind(theta)^2)*0.5;

V=(1+term*(term2-term3))*v_c

figure(1)

hold on

plot([v1 v2 v3 v4],[p1 p2 p3 ],\'color\',\'r\')

thermal_efficiency =1-(t4-t1)/(t3-t2)