Air standard cycle

Aim:

To create a plot on Air standard cycle and engine kinematics with otta cycle using matlab

Formulae:

%Ottocycle
clear all 
close all
clc

% Inputs
gamma = 1.4
t3 = 2300

% State variables
p1 = 101325
t1 = 500

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

%Calculating the swept volume and the clearence 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 stable point 2
% p2v2^gamma = p1v1^gamma
% p2 = p1*(v1/v2)^gamma = p1*cr^gamma
p2 = p1*cr^gamma;

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

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

P_compression = constant_c./V_compression.^gamma;





%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,180,0);

P_expansion = constant_c./V_compression.^gamma;



% State varaible at state point 4
v4 = v1

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

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')

figure(2)
plot([v1 v2 v3 v4 v1],[p1 p2 p3 p4 p1],'color','b')

%EngineKinematics
function[V] = engine_kinematics(bore, stroke, con_rod, cr, start_crank, end_crank)



a = stroke/2;
R = con_rod/a;

v_s = pi/4*bore^2*stroke;
v_c = v_s/(cr-1);

theta = linspace(start_crank, end_crank,100);

term1 = 0.5*(cr-1);
term2 = R +1 - cosd(theta);
term3 = (R^2 - sind(theta).^2).^0.5;



V = (1 + term1*(term2 - term3)).*v_c;



end

Discription:

We are creating a plot using matlab for Air standard cycle in ottocycle. Air standard dynamics define the air inlet and outlet in engine during the crank movement. The heating cycle in engine kinematics during bore stroke define the efficency of engine. The movement of crank from start to end cycle is is shown in plot using point value. The flow diagram in next stage shows the heat and compression ratio of engine during the total heat cycle.

Conclusion:

Thus we successfully plotted and created a flow diagram using matlab during the ottocycle.

Output: