Contents
discussion de l'évolution du rendement
%calcul en fct de epsilon1 et Q1
contact
auteur : remy.cann@ac-rennes.fr lycée Vauban BREST
constantes
clc
clear
p1=10^5;
T1=298;
gamma=1.4;
cv=716.7;
rho=p1/287/T1; %kg/m3 ou g/L;
Q1=[100:50:550];
epsilon1=[6:0.5:12];
epsilon2=17.7;
V1=150;
V2=450;
vm2=V2/(epsilon2-1);
n1=size(epsilon1);
m1=size(Q1);
Wech=0.000001*p1*(V2-V1);
Wech_graph=ones(n1(2),m1(2))*Wech;
calculs et formation des tables
for i = 1:n1(2) for j=1:m1(2) %eta bdr eta_bdr(i,j)=1-epsilon1(i)^(1-gamma); Q2(i,j)=Q1(j)*(eta_bdr(i,j)-1); WBdr(i,j)=-Q1(j)*eta_bdr(i,j); %masse en oeuvre vm1(i,j)=V1/(epsilon1(i)-1); masse(i,j)=rho/1000*(V1+vm2+vm1(i,j)); %T5 et p5 T5(i,j)=-Q2(i,j)/(masse(i,j)/1000*cv)+T1; p5(i,j)=T5(i,j)/T1; %epsilon détente prolongée epsilon_det(i,j)=(vm2+V2+vm1(i,j))/(V1+vm2+vm1(i,j)); %travail détente prolongee Wdet_prol(i,j)=0.1*p5(i,j)*(V1+vm2+vm1(i,j))/(gamma-1)*(epsilon_det(i,j)^(1-gamma)-1); %rendement eta_cycle(i,j)=abs((WBdr(i,j)+Wech+Wdet_prol(i,j))/Q1(j)); end end
graphes
scrsz = get(0,'ScreenSize'); figure('name','rendement du cycle 5T = f(Q1, epsilon1)','Position',[30 scrsz(4)/4 5*scrsz(3)/6 2*scrsz(4)/3],'NumberTitle','off') subplot(2,2,1) meshz(Q1,epsilon1,eta_cycle) title ('rendement théorique _ epsilon2 = 17,7 _ Vcyl1=150 cm3 _ V2 = 450 cm3','fontsize',14) colormap copper xlabel ('Q1 (J)','fontsize',14) ylabel ('epsilon1','fontsize',14) g=gca; set(g,'fontsize',16) subplot(2,2,2) [C,h]=contour(Q1,epsilon1,eta_cycle,'k','LineWidth',1); clabel(C,h) grid on title ('rendement théorique _ epsilon2 = 17,7 _ Vcyl1=150 cm3 _ V2 = 450 cm3','fontsize',14) xlabel ('Q1 (J)','fontsize',14) ylabel ('epsilon1','fontsize',14) text_handle = clabel(C,h); set(text_handle,'fontsize',14) g=gca; set(g,'fontsize',16) subplot(2,2,3) meshz(Q1,epsilon1,Wdet_prol) title ('travail de détente prolongée _ epsilon2 = 17,7 _ Vcyl1=150 cm3 _ V2 = 450 cm3','fontsize',14) colormap copper xlabel ('Q1 (J)','fontsize',14) ylabel ('epsilon1','fontsize',14) h=gca; set(h,'fontsize',16) subplot(2,2,4) meshz(Q1,epsilon1,Wech_graph) title ('travail échappement _ epsilon2 = 17,7 _ Vcyl1=150 cm3 _ V2 = 450 cm3','fontsize',14) colormap copper xlabel ('Q1 (J)','fontsize',14) ylabel ('epsilon1','fontsize',14) h=gca; set(h,'fontsize',14)
