Finite Difference Scheme Error
2 views (last 30 days)
Show older comments
Hi, I am trying to plot this equation , i am unable to understand how to debug the matrix error on the equation.
% Solution 1: Chemical Species Concentration as a Function of Axial Distance
clc
clear
% Constants
L = 0.2;
N = 31;
T(1:N) = 700;
delx = L/(N-1);
xspan = 0:delx:0.2;
u = 1.5;
A = 7e4;
Ea = 100000;
Ru = 8.3145;
T = 700;
k = 0.035;
rho = 0.95;
NM=3;
C(1) = 0.21;
C(2) = 0.68;
C(3) = 0.06;
R(1) = -A * (exp(-Ea / (Ru*T))) * C(1)/rho * sqrt(C(2)/rho);
R(2) = 0.5 * R(1);
R(3) = -R(1);
D(1) = 0.166;
D(2) = 0.201;
D(3) = 0.177;
for i=2:N-1
for j=2:NM
C(i,j)=((R(j)*delx.^2)*(rho*D(j)).^(-1))+ C(i+1,j)+C(i-1,j) ;
end
end
% Plots
subplot(2,1,1);
plot(x,C(:,1),'b--o',x,C(:,2),'g--+',x,C(:,3),'r--s')
legend('C_{CO}','C_{O2}','C_{CO2}')
xlabel('Axial (x) Direction [m]')
ylabel('Concentrations [mol/m^3]')
title('Molar Concentration vs Distance')
subplot(2,1,2);
plot(x,T,'b--*')
legend('Gas Temperature')
xlabel('Axial (x) Direction [m]')
ylabel('Gas Temperature [K]')
title('Temperature vs Distance')
Any help is appreciated.
Thank You
0 Comments
Accepted Answer
Torsten
on 10 Apr 2017
In the calculation of C(i,j), you can't refer to C(i+1,j) because it's not yet defined.
Best wishes
Torsten.
More Answers (0)
See Also
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!