Contents
discussion de l'évolution du rendement
%calcul en fct de epsilon2 et V2
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=532.78;
epsilon1=7;
epsilon2=[10:1:20];
V1=150;
vm1=V1/(epsilon1-1);
V2=[200:100:1000];
n1=size(epsilon2);
m1=size(V2);
eta_bdr=1-epsilon1^-0.4;
WBdr=-Q1*eta_bdr;
Q2=Q1*(eta_bdr-1);
calculs _ formation des tables
for i = 1:n1(2) for j=1:m1(2) %masse en oeuvre vm2(i,j)=V2(j)/(epsilon2(i)-1); masse(i,j)=rho/1000*(V1+vm1+vm2(i,j)); %T5 et p5 T5(i,j)=-Q2/(masse(i,j)/1000*cv)+T1; p5(i,j)=T5(i,j)/T1; %epsilon détente prolongée epsilon_det(i,j)=(vm1+V2(j)+vm2(i,j))/(V1+vm1+vm2(i,j)); %travail détente prolongee Wdet_prol(i,j)=0.1*p5(i,j)*(V1+vm1+vm2(i,j))/(gamma-1)*(epsilon_det(i,j)^(1-gamma)-1); %travail échappement Wech(i,j)=0.000001*p1*(V2(j)-V1); %rendement eta_cycle(i,j)=abs((WBdr+Wech(i,j)+Wdet_prol(i,j))/Q1); end end
graphes
scrsz = get(0,'ScreenSize'); figure('name','rendement du cycle 5T = f(V2, epsilon2)','Position',[30 scrsz(4)/4 5*scrsz(3)/6 2*scrsz(4)/3],'NumberTitle','off') subplot(2,2,1) meshz(V2,epsilon2,eta_cycle) title ('rendement théorique _ epsilon1 = 7 _ Vcyl1=150 cm3 _ Q1 = 530 J','fontsize',14) colormap copper xlabel( 'V2 (cm3)','fontsize',14) ylabel ('epsilon2','fontsize',14) g=gca; set(g,'fontsize',16) subplot(2,2,2) [C,h]=contour(V2,epsilon2,eta_cycle,'k','LineWidth',1); clabel(C,h) grid on title ('rendement théorique _ epsilon1 = 7 _ Vcyl1=150 cm3 _ Q1 = 530 J','fontsize',14) xlabel( 'V2 (cm3)','fontsize',14) ylabel ('epsilon2','fontsize',14) text_handle = clabel(C,h); set(text_handle,'fontsize',14) g=gca; set(g,'fontsize',16) subplot(2,2,3) meshz(V2,epsilon2,Wdet_prol) title ('travail de détente prolongée _ epsilon1 = 7 _ Vcyl1=150 cm3 _ Q1 = 530 J','fontsize',14) colormap copper xlabel( 'V2 (cm3)','fontsize',14) ylabel ('epsilon2','fontsize',14) h=gca; set(h,'fontsize',14) subplot(2,2,4) meshz(V2,epsilon2,Wech) title ('travail échappement _ epsilon1 = 7 _ Vcyl1=150 cm3 _ Q1 = 530 J','fontsize',14) colormap copper xlabel( 'V2 (cm3)','fontsize',14) ylabel ('epsilon2','fontsize',14) h=gca; set(h,'fontsize',14)
