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System of PDEs

  1. Jan 2, 2004 #1
    I have two unknown function namely u(x,y) and v(x,y). These functions are part of two coupled partial differential equations. I realize that it will be almost impossible to get a general solution seeing as one on the PDEs is non-linear. But given a set of boundary conditions I wish to solve for these unknown functions numerically. I don’t quite know how to go about this though, so any help would be appreciated. The equations are attached to this thread

    Attached Files:

  2. jcsd
  3. Jan 7, 2004 #2
    If I wanted to solve this numerically, I'd use a finite-timestep approach.


    [tex]\frac{\partial f(x)}{\partial x} \equiv \lim_{\Delta x \rightarrow 0}\frac{f(x+\Delta x)-f(x)}{\Delta x}[/tex]

    So: just make sure that your timestep [itex]\Delta x[/itex] is small compared to the (expected) fluctuations in your solutions. In that case, you can re-write your equations in an iterative form (note that I used [itex]\Delta x=1[/itex]):

    [tex] f(n+1) = {\rm some\; function\; of}\; f(n)[/tex]

    which you can do for both of your functions. Now, you can start with your boundry values (for time [itex]n=0[/itex]) and generate the solutions for [itex]n>0[/itex] with a computer. Computationally intensive, but that should be no problem for your equations...

    Last edited: Jan 7, 2004
  4. Jan 15, 2004 #3
    It looks to me as though this is a problem from complex analysis. Your second equation is the analyticity condition for a function of a complex variable. Perhaps the first equation is simply expressed in terms of that function.

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