I found the missing part. Since it's in spherical coordinates (m=2), then all left boundary conditions should be ignored which is translated to be Neumann boundary conditions.
No Results from pdepe Solver
1 vue (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Meteb Mejbel
le 5 Juil 2021
Réponse apportée : Meteb Mejbel
le 5 Juil 2021
Hi all,
I am trying to solve a system of multivariables pdes using pdepe solver. Everything seems good, however, the results of all concentration variables do not show any change. One thing I've noticed, the boundary conditions do not appear in the graphs as shown below especially the left ones (all of them are constants CA(0,t)=1CB(0,t)=1, CD(0,t)=2, CC(0,t)=2. I am providing my codes too.
function pdepesolver
clear;
R=1;
tend=1;
m=2;
x=linspace(0,R,2000);
t=linspace(0,tend,1000);
sol=pdepe(m, @pdepet1func,@pdepet1ic, @pdepet1BC, x, t);
A=sol(:,:,1);
B=sol(:,:,2);
D=sol(:,:,3);
C=sol(:,:,4);
figure(1)
surf(x,t,A)
title('concentration of A')
xlabel('x')
ylabel('t')
zlabel('C_A')
figure(2)
surf(x,t,B)
title('concentration of B')
xlabel('x')
ylabel('t')
zlabel('C_B')
figure(3)
surf(x,t,D)
title('concentration of D')
xlabel('x')
ylabel('t')
zlabel('C_D')
figure(4)
surf(x,t,C)
title('concentration of C')
xlabel('x')
ylabel('t')
zlabel('C_C')
function [pl, ql, pr, qr]=pdepet1BC(xl, ul, xr, ur, t)
pl=[ul(1)-1; ul(2)-1; ul(3)-2; ul(4)-2];
ql=[0; 0; 0; 0];
pr=[0;0;0;0];
qr=[1;1;1;1];
function [c,f,s]=pdepet1func(x,t,u,dudx)
DA=0.25;
DB=0.7;
DD=0.15;
DC=0.4;
muA=0.35;
muB=0.5;
muD=0.5;
c=[1; 1; 1; 1];
f=[DA*dudx(1)-(1/(muA*u(1)+muB*u(2)+4*muD*u(3)))*(muA*u(1)*DA*dudx(1)-muA*u(1)*DB*dudx(2)-2*muA*u(1)*DD*dudx(3));
DB*dudx(2)-(1/(muA*u(1)+muB*u(2)+4*muD*u(3)))*(muB*u(2)*DA*dudx(1)-muB*u(2)*DB*dudx(2)-2*muB*u(2)*DD*dudx(3));
DD*dudx(3)-(1/(muA*u(1)+muB*u(2)+4*muD*u(3)))*(2*muD*u(3)*DA*dudx(1)-2*muD*u(3)*DB*dudx(2)-4*muD*u(3)*DD*dudx(3));
DC*dudx(4)];
s=[0; 0; 0; 0];
function u0=pdepet1ic(x)
u0=[0.001;0.001;0.001;0.001];
0 commentaires
Réponse acceptée
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur PDE Solvers dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!