1
   

Is there analitical solution of the problem?

 
 
Reply Sun 3 Oct, 2004 03:09 pm
The nonlinear equations are very impotant in many areas of physics,
but the exact analitycal solutions are known only for some equations
of specific form. Recently I've come across the following problem.
imagin you have the liquid near critical point, the behavior of such
fluid is determined by so called Ginzburg-Landau equation. It may be
written in the next form (TeX notations)

-\triangle \rho +(\rho-\rho_1)(\rho-\rho_2)(\rho-(rho_1+rho_2)/2)=0

here \rho_1 and \rho_2 are the constants (the liquid and gase phase
densities). I need the analitycal solution of this problem in the case
of spherical symmetry and under the following boundary conditions
\rho(R)=0, R<\infty
\rho(\infty)=\rho_2
The sollution corresponds to the bubble dissolved in water.
I admit that there is no such solution but the equation is very simple
and it should be in my opinion. Suppose there is no one then if the solution of
the problem exists when \rho_1=0
or in other words
-\frac{d^2 \rho}{dr^2}-\frac{2}{r} \frac{d\rho}{dr}+\rho (\rho-\rho_2)
(\rho-\rho_2/2)=0
\rho(R)=0
\rho(\infty)=\rho_2
Ideed I don't need the strict derivation of the solution, It would be enough to know if there is one and may be how to find it in some words.
Thank you.
George
  • Topic Stats
  • Top Replies
  • Link to this Topic
Type: Discussion • Score: 1 • Views: 697 • Replies: 4
No top replies

 
KellyS
 
  1  
Reply Mon 4 Oct, 2004 12:59 am
This is definitly not my field. However, I think a paper was written on this problem as a doctoral thesis about 1979 at the University of New Mexico, Albuquerque in the Chemistry department. Sorry, while I can see the guy's face, who was doing the research while I was in EE grad school, I can't recall his name.

I don't know what is on line, but perhaps you can do a search of PhD disertations at UNM that year, give or take 1, and find the paper that will answer your question.

Kelly
0 Replies
 
stuh505
 
  1  
Reply Mon 4 Oct, 2004 08:31 am
george, could you write that problem up on paper and scan it in?
0 Replies
 
george91
 
  1  
Reply Mon 4 Oct, 2004 10:31 am
stuh505 wrote:
george, could you write that problem up on paper and scan it in?

Yes, of course. But I don't know how to attach a picture here
0 Replies
 
Joe Republican
 
  1  
Reply Mon 4 Oct, 2004 06:13 pm
george91 wrote:
stuh505 wrote:
george, could you write that problem up on paper and scan it in?

Yes, of course. But I don't know how to attach a picture here


Upload it to a website and use the tags {img} and {/img} replacing the brackets with [ and ] where the and word is, replace it with the link to the picture location on the net.

for example, you can get a picture like this

http://www.pbs.org/wgbh/nova/elegant/images/elegant-home.jpg

You can quote my post to see the format of the img tag if you don't understand.


I'm not sure from your formula and it has been many years since I've opened up a diff-eq book, but I think it all depends on your initial boundary conditions. Can you simplify the diffeq' with Laplace transform, or would you use a Fourier series to simplify it?

Either way, if you can upload the scanned text, I can take a look at the problem and I may be able to offer an opinion. Chances are thought, it will most likely be over my head since it's been so long since I've looked at diff-eq's.
0 Replies
 
 

Related Topics

Evolution 101 - Discussion by gungasnake
Typing Equations on a PC - Discussion by Brandon9000
The Future of Artificial Intelligence - Discussion by Brandon9000
The well known Mind vs Brain. - Discussion by crayon851
Scientists Offer Proof of 'Dark Matter' - Discussion by oralloy
Blue Saturn - Discussion by oralloy
Bald Eagle-DDT Myth Still Flying High - Discussion by gungasnake
DDT: A Weapon of Mass Survival - Discussion by gungasnake
 
  1. Forums
  2. » Is there analitical solution of the problem?
Copyright © 2025 MadLab, LLC :: Terms of Service :: Privacy Policy :: Page generated in 0.03 seconds on 01/17/2025 at 10:53:54