Air standard Cycle

1) Matlab code to create a otto cycle PV diagram

clear all
close all
clc

%input variables
gamma = 1.4
t3= 2300

% state variables
p1=101325
t1=500;

% engine geometric parameter
bore=0.1;
stroke=0.1;
con_rod=0.15;
cr=12;

% calculating the swept volumeand the 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*cr^gamma

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


constant_c = p1*v1^gamma;
V_compression = piston_kinematicsfunction(bore, stroke,con_rod,cr,180,0 ) 

P_compression = constant_c./V_compression.^gamma;

% state variables at state point 3
v3=v2;

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

constant_c = p3*v3^gamma;
V_expansion = piston_kinematicsfunction(bore, stroke,con_rod,cr,180,0) 

P_expansion = constant_c./V_compression.^gamma;


% state variables at state point 4
v4=v1;

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

% efficiency of otto cycle
efficiency = 1 - ((1/cr)^(gamma-1))

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])
plot ([v4,v1],[p4,p1])
xlabel (\'volume\')
ylabel (\'pressure\')

figure (2)

plot ([v1 v2 v3 v4 v1],[p1 p2 p3 p4 p1],\'color\',\'b\')

2) You should output the thermal efficiency of the engine= 0.6299

3) Outputs screenshot