Important: help with pdepe used in a system of pdes and odes...

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Nadine 2011-11-21

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/21824-important-help-with-pdepe-used-in-a-system-of-pdes-and-odes

Hi, for simulation purpose I try to solve a system of nine differential equations where from the first three are ode's (t) and the others are pde's (t,z). They are all coupled and I try to solve them with pdepe. I get the following error message:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

??? Error using ==> daeic12 at 77
This DAE appears to be of index greater than 1.
Error in ==> ode15s at 389
    [y,yp,f0,dfdy,nFE,nPD,Jfac] = daeic12(odeFcn,odeArgs,t,ICtype,Mt,y,yp0,f0,...
Error in ==> pdepe at 317
  [t,y] = ode15s(@pdeodes,t,y0,opts);
Error in ==> Simulation at 29
sol = pdepe(m,@pdefun,@pdex4ic,@pdex4bc,x,t);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

What do I have to change to make to programm running?

Definitions of the function (may not be needed):

c = [1;1;1;1;1;1;1;1;1];
f = [0;...
0;...
0;...
Permkaptonco2*(u(1)-u(4));...
Permkaptonh2*(u(2)-u(5));...
Permkaptonn2*(u(3)-u(6));...
Permzouco2*(u(1)-u(7))+Permcarrier*(K*u(1)*ccarrier/(1+K*u(1))-K*u(7)*ccarrier/(1+K*u(7)));...
Permzouh2*(u(2)-u(8)); ...
Permzoun2*(u(3)-u(9))];
s = [(Pin-(u(1)+u(2)+u(3))).*ninco2-Permkaptonco2.*(u(1)-u(4))-Permzouco2.*(u(1)-u(7))./dzou-Permcarrier.*(K.*u(1).*ccarrier./(1+K.*u(1))-K.*u(7).*ccarrier./(1+K.*u(7)));...
     (Pin-(u(1)+u(2)+u(3))).*ninh2- Permkaptonh2.*(u(2)-u(5))-Permzouh2.*(u(2)-u(8))./dzou;...
     (Pin-(u(1)+u(2)+u(3))).*ninn2- Permkaptonn2.*(u(3)-u(6))-Permzoun2.*(u(3)-u(9))./dzou;...
    0;...
    0;...
    0;...
    0;...
    0;...
    0];