Week 2 Air standard Cycle

%otto cycle
clear all
close all
clc

%input
gamma=1.4;
p1=101325;
t3=2300;

%engine kinematics

%compression ratio
cr=12;

%bore (m)
bore=0.1;

%stroke (m)

stroke=0.1;

con_rod=0.15;

%swept volume
v_s=pi*bore^2*stroke/4;

%clearance volume
v_c=v_s/(cr-1);

%state point1
v1=v_c+v_s;
t1=500;
%state point2
v2=v_c;
p2=p1*cr^gamma;
t2=t1*cr^(gamma-1);

%for volume trace
Constant_c=p1*v1^gamma;
V_compression=engine_kinematics(bore,stroke,con_rod,cr,180,0);
P_compression=Constant_c./(V_compression).^gamma;

%state point3
v3=v2;
p3=p2*t3/t2;

%state point4

v4=v1;
p4=p3*(v3/v1)^(gamma);

V_expansion=engine_kinematics(bore,stroke,con_rod,cr,180,360);

Expansion_constant=p3*v3^gamma;
P_expansion=Expansion_constant./(V_expansion).^gamma;

%thermal efficiency

efficiency=(1-(1/(cr)^(gamma-1)))*100 ;

display(['Thermal Efiiciency=',num2str(efficiency),'%'])

figure(1)
hold on
plot(v1,p1,'*','color','r')
plot(v2,p2,'*','color','r')
plot(V_compression,P_compression)
plot(v3,p3,'*','color','r')
plot(v4,p4,'*','color','r')
plot(V_expansion,P_expansion)
grid on

title('P-V diagram')
xlabel('volume axis')
ylabel('pressure axis')

plot([v2 v3],[p2 p3])
plot([v1 v4],[p1 p4])

results:-