Week 2 Air standard Cycle

% define the function to calculate volume

function[func]= engine_kinematics(bore,stroke,con_rod,cr,start_crank,end_crank)

a = sroke/2;

R= con_rod/a

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

v_clearance=v_swept/(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_trace= (1+term1*(term2-term3))*v_clearnce;

end

% main console

clear all

clase all

clc

% Input Parameters

% temperatures(in kelvin)

t1=600

t3=2400

% pressure(in Pa)

p1=101325

gamma=1.4

% engine geometric parameters

bore=0.1;

stroke=0.1;

con_rod=0.15;

cr=12;

%swept_volume and clearance_volume

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

v_clearance=v_swept/(cr-1);

v1= v_swept+v_clearance;

v2= v_clearance;

% calculating the state variables at point 2

p2= p1*cr^gamma;

t2= t1*cr^(gamma-1);

v_compression = engine_kinematics(bore,stroke,con_rod,cr,180,0);

constant_compression= p1*v1^gamma;

p_compression= constant_compression/(v_compression.^gamma);

% calculating state variablesat point 3

v3=v2;

p3=p2*t3/t2;

% calculating the state variables at point 4

v4=v1;

p4 = p3*(1/cr)^(gamma-1);

t4 = t3*(1/cr)^(gamma-1);

v_expansion= engine_kinematics(bore,stroke,con_rod,cr,0,180);

constant_expansion= p3*v3^gamma;

p_expansion = constant_expansion./(v_expansion.^gamma);

% calculating efficiency

thermal eficiency = 1-{(t4-t1)/(t3-t2)}

% plotting

figure(1)

hold on

plot(v1,p1,\'*r\')

plot(v2,p2,\*b\')

plot(v3,p3,\*g\')

plot(v4,p4,\*r\')

plot(v_compression,p_compression)

plot([v2 v3], [p2 p3])

plot(v_expansion, p_expansion)

plot( [v4 v1], [p4,p1])

xlabel("volume");

ylabel("pressure")