Solving and plotting ode's in matlab
7 views (last 30 days)
Show older comments
%reaction data
E1=42; % forward activation energy
Cn2=1; % feed concentration
R =8.314;
A1=.04;
A2=.1;
Co2=1;
Fa0= Cn2 + Co2;
T0=500 ; % feed temperature
Cpn2 =29.7198; Cpo2=29.051; Cpno =29.3018; %j/mol.K
deltaCp = 2*Cpno-Cpo2-Cpno;
Hrxn = 180.5; % kj/mol at refrence temp 300K
Ua =0.01;
Ta0 =550;
mc = 0.011
Cpc= 34.5
syms X(V) T(V) Ta(V)
ra = -A1*exp(-E1/(8.314*T))*(Cn2^2)*((1-X)^2)*((T0/T)^2);
eqn1 = diff(X, V) == ra/Fa0; %X
eqn2 = diff(T, V) == (Ua*(Ta-T)+ra*Hrxn)/(Fa0*(Cn2*Cpn2+Co2*Cpo2)); %T
eqn3 = diff(Ta, V) == Ua*(Ta-T)/(mc*Cpc);
[odes, vars] = odeToVectorField(eqn1, eqn2, eqn3);
fun = matlabFunction(odes,'Vars',{'t','Y'});
x0 = [0 500 550 ];
tspan = [0 550];
[t, sol] = ode45(fun,tspan,x0);
X = sol(:,1);
T = sol(:,2);
Ta = sol(:,3);
plot(t,sol(:,1))
hold
grid
title('X vs Volume')
xlabel('Volume')
ylabel('X')
hold off
plot(t,sol(:,2),t,sol(:,3)) %plotting Ta on same graph
hold
grid
title('T vs Volume')
xlabel('Volume')
ylabel('T')
hold off
for i = 1:501
Ra(i) = Fa0*(sol(i,2)/t(i,1));
plot(t,Ra)
hold
grid
title('-ra vs V')
xlabel('Volume')
ylabel('-ra')
hold off
end
- This is my new code. Although i think i properly indexed everything the output is not as expected.
- Except the initialized values all values of sol array is NaN for some reason.
6 Comments
Answers (0)
See Also
Categories
Find more on Ordinary Differential Equations in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!