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System of DEs with different denominators

  1. Apr 14, 2008 #1
    system of DEs with different "denominators"


    Sorry in advance for the lack of knowledge of the techincal terms.

    I am trying to solve a system of differential equations numerically, and I am not sure how to go about it. I've got 7 equations total; 5 of the form dT/dt = f(T1,T2,T3...) and 2 of the form dT/dx = f(T1,T2,T3...) .

    ***Note*** dT could be dT1, dT2, dT3...

    How can I solve this numerically? I was looking at Runge-Kutta, but I'm not sure that I can since some equations have different "denominators".

    Does anybody understand what I'm trying to ask? If you need more info, let me know.

    I attached a pdf of the equations if that can help... Those equations will actually change (I just wrote them up really quickly, and I know that there are lots of mistakes in them) but it should give you a good idea of the problem. Some of the h coefficient are functions of T, m1 and m2 are functions of x.

    Thanks for any kind of help

    Attached Files:

    Last edited: Apr 14, 2008
  2. jcsd
  3. Apr 15, 2008 #2


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    So these are partial differential equations? That is your functions depend upon the two independent variables x and t?
  4. Apr 15, 2008 #3
    Yes. I wasn't sure if you could call them partial because each equation only depends on dT/dx or dT/dt, not both at the same time.

    As you probably suspect, math is NOT my forte. I am just starting a Masters in mech. eng. and my differential equations course was 3 years ago. I forgot everything I learned in that class as soon as I wrote the final ;) I do remember most of my numerical classes though (although I don't beleive we spent much time on systems of differential equations).

    Last edited: Apr 15, 2008
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