# Help in solving PDE

1. Jan 21, 2010

### alokgautam

Hello friends please attached file to see my problem

Last edited: Mar 31, 2010
2. Jan 22, 2010

### gato_

First term is actually the expression for mean curvature (H(z(x,y))) for a local patch. your equation reads:
$$H-z/c=0$$
(is that a bubble subject to gravity?) that said, I think you might better try an axysimmetric solution first, z(r), as your forcing (z/c) does not depend on x or y.
$$\frac{z_{,rr}}{(1+z_{r}^{2})^{3/2}}+\frac{z_{,r}}{r(1+z_{,r}^{2})^{1/2}}-z/c=0$$
this is an ODE (a though one). You should add your conditions, depending on wether the surface is closed (periodicity) or open (contact angle somewhere). Finding equilibrium configurations of free surfaces is not easy!

3. Jan 24, 2010

### alokgautam

Hi,
Yes you are write this first term is mean curvature.
For axysimmetric this become Second order differential equation that is easy to solve. I already did that part now I am looking for 3D system. If u can help in the derivation of this equation that will be very helpful for me for me.
Is there any site in which the derivation of this equation is given.
Rest is fine
Take care
alok

4. Jan 26, 2010

### gato_

5. Jan 26, 2010

### alokgautam

Dear Friend,
Thank you very much.
I will try this surface evolver software.
rest is fine
take care
Alok