Engine kinematics - otto cycle

clear all
close all
clc

% Inputs
gamma = 1.4
t3 = 2300

% State Variables
p1 = 101325
t1 = 500

% Engine geometric parameters
bore = 0.1;
stroke = 0.1;
con_rod = 0.15;
cr = 12;

% Calculating swept and clearance volume
v_swept =(pi/4)*bore^2*stroke;
v_clearance = v_swept/(cr-1);

v1 = v_swept + v_clearance;
v2 = v_clearance;

% State variables at state point 2
% p2v2^gamma = p1v1^gamma
% p2 = p1*(v1/v2)^gamma
p2 = p1*cr^gamma;

constant_c = p1*v1^gamma;
V_compression = Engine_Kinematics(bore,stroke,con_rod,cr,180,0);
P_compression = constant_c./V_compression.^gamma;

% p1v1/t1 = p2v2/t2 | t2 = (p2*v2*t1)/(p1*v1)
t2 = p2*v2*t1/(p1*v1);

% State variables at state point 3
v3 = v2;

%p3v3/t3=p2v2/t2|p3=p2*t3/t2
p3 = p2*t3/t2;

constant_c = p3*v3^gamma;
V_expansion = Engine_Kinematics(bore,stroke,con_rod,cr,0,180);
P_expansion = constant_c./V_expansion.^gamma;

% State variables at state 4
v4 = v1

%p3v3^gamma=p4v4^gamma| p4 = p3*(v3/v4)^gamma
p4 = p3*(v3/v4)^gamma;

% p4v4/t4 = p1v1/t1
t4 = p4*t1/p1;

% thermal efficiency of otto cycle n;

n = 1 - (t4-t1)/(t3-t2);

% plotting
figure(1)
hold on
plot(v1,p1,\'*\',\'color\',\'r\')
plot(V_compression,P_compression)
plot(v2,p2,\'*\',\'color\',\'r\')
plot(v3,p3,\'*\',\'color\',\'r\')
plot(V_expansion,P_expansion)
plot(v4,p4,\'*\',\'color\',\'r\')
plot([v2 v3],[p2 p3],[v4 v1],[p4 p1],\'color\',\'y\')
xlabel(\'volume\')
ylabel(\'pressure\')
grid on