heatexco.m

for the parameter estimation and plot the temperature profile for the exchanger

function f=heatexco(t,x)

f(1)=(1/0.1)*(0.5*exp(15*x(2)/(1+x(2)))*(1-x(1)));
f(2)=(1/0.1)*(-(1.6*(x(2)-x(4)))-(0.4*(0.5*exp(15*x(2)/(1+x(2)))*(1-x(1)))));
f(3)=(1/0.25)*(0.5*exp(15*x(4)/(1+x(4)))*(1-x(3)));
f(4)=(1/0.25)*((4*(x(2)-x(4)))+(0.4*(0.5*exp(15*x(4)/(1+x(4)))*(1-x(3)))));

f=f';