OTTO CYCLE

THE CODE GIVES THE THERMAL EFFICIENCY OF THE ENGINE AND ALSO PLOTS THE PV DIAGRAM

clear all close allclc gamma=1.4;t3=2300;% state variablesp1=101325;t1=500; %Engine geometric parametersbore=0.1;stroke=0.1;con_rod=0.15;cr=12; v_s=(pi/4)*bore^2*stroke;v_c=v_s/(cr-1); v1=v_s+v_c;v2=v_c; %state variable at point 2p2=p1*cr^gamma;t2=p2*v2*t1/(p1*v1); constant_c=p1*v1^gamma; V_compression = engine_kinematics(bore,stroke,con_rod,cr,180,0); P_compression = constant_c./V_compression.^gamma; %state variables at point 3 v3=v2; 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 point 4 v4=v1; p4=p3*(v3/v4)^gamma; hold on plot(v1,p1,'.','color','b'); plot(V_compression,P_compression,'color','r'); plot(v2,p2,'.','color','b'); plot(v3,p3,'.','color','b'); plot(V_expansion,P_expansion,'color','g'); plot(v4,p4,'.','color','b'); plot([ v2 v3 ],[ p2 p3],'linewidth',1,'color','b'); plot([ v4 v1 ],[ p4 p1],'linewidth',1,'color','b'); xlabel('Volume (m^3)'); ylabel('Pressure (N/m^2)'); grid on Eta=1-(1/(cr^(gamma-1))); TE=Eta*100; fprintf('Thermal_efficiency=%f \n',TE)