Untitled

global T0 T4 k z
T0=273.15; %[K]
T4=373.15, %[K]
k=[3 1.5 5 2] %[W/m*K]
z=[0 0.1 0.2 0.4 0.45] %[m]

function y=equazioni(x)
global T0 T4 k z
T1=x(1);
T2=x(2);
T3=x(3);
q=x(4);

y(1)=k(1)*(x(1)-T0)/(z(2)-z(1))-x(4);
y(2)=k(2)*(x(2)-x(1))/(z(3)-z(2))-x(4);
y(3)=k(3)*(x(3)-x(2))/(z(4)-z(3))-x(4);
y(4)=k(4)*(T4-x(3))/(z(5)-z(4))-x(4);

end

x0=[280 300 330 50];
fun=fsolve(@equazioni, x0);

T1=fun(1);
T2=fun(2);
T3=fun(3);
q=fun(4);

fprintf('T1= %.4f K\n', fun(1));
fprintf('T2= %.4f K\n', fun(2));
fprintf('T3= %.4f K\n', fun(3));
fprintf('q= %.4f K\n', fun(4));

T=[T0,T1,T2,T3,T4];
figure;
plot(z,T, 'b-', 'LineWidth', 1.5);
hold on;
xlabel('z(m)');
ylabel('Temperatura(K) ');
title('Tank Temperature');
grid on;