pdepe solver for spherical coordinates

I am using the heat conduction equation for solid which has the source term to enter the code in Matlab. But even changing any values of s the plot is not chnaging atall. What could be the problem?

[Torsten]

We don't know since we don't know the code you are using.

[John D'Errico]

Probable user error. A mistake you made in either running or writing the code.

Think about it. Read your question, as if you were yourself trying to provide help. We are expected to know what you did wrong, based only on being told that when you change the value of s, nothing happens. What is s? Now think about how we should know the answer to your question from that little information.

Seriously. Do you want a better answer? You need to provide more information. You might show the code you wrote, and hope someone will be willing to dive into it. If you do that, then you also need to show the actual equations you are trying to solve, so that same person might be able to verify if you implemented them properly.

[Ishani Prachchhak]

m=0; %for spherical symmetry

egen=1.234e19;%Energy absorbed per unit volume(W/m^3)

k=5.9;%(W/m.K)

Tinfi=296;

x=linspace(0,15e-9,20); %m

t= linspace(0,1e-10,20);

%x=r u=T

sol=pdepe(m,@pdefun,@pdeic,@bc,x,t);

u=sol(:,:,1);

surf(x,t,u);

xlabel('r');

ylabel('t');

function [c,f,s]= pdefun(x,t,u,dudx);

alpha=7.9e-9;%(m^2)/s

egen=1.12157e-05;

k=5.9;%(W/m.K)

c=1/alpha;

f=(dudx)*x^-2;

s=egen/k;

end

function T0=pdeic(x)

T0=296;

end

function [pl,ql,pr,qr]= bc(xl,ul,xr,ur,t)

k=5.9;%(W/m.K)thermal conductivity

x=15e-9;

A=4*3.14*(x)^2;%Area

pl= 0;

ql= 1;

pr=1.234e19;

qr=-2*k;

end

[Ishani Prachchhak]

[Ishani Prachchhak]

I am trying to solve for constant conductivity equation using pdepe.

[Torsten]

You set up the following problem:

1/alpha * du/dt = d/dx ( 1/x^2 * du/dx) + egen/k
u(t=0) = 296
1/x^2 * du/dx = 0 at x=0
1.234e19 - 2*5.9/x^2 * du/dx = 0 at x = 15e-9.

Is this really what you try to solve ?

If not: please include equation, initial and boundary conditions.