Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Non-linear ODE

  1. Feb 8, 2012 #1
    In the course of trying to solve the field equations of a physical system, within some assumptions about its symetry, i managed to get a non-linear ODE involving only a single function of one variable, but still rather tough to handle :
    In the equation, x=x(r) is the unknown function to find, and p0, p1, p2 are KNOWN algebraic functions of r (that i didn't take the time to write down here, but are not too complicated functions).

    p0*(x''-x'²) + x'(x²+2x) (-/+) p1*x^4 + p2*x³ - p2*x² (+/-) p1*x = 0

    Do you guys have any ideas of how i could manage to obtain any analytic solution for x(r)?
    I can't find any help, because its not a categorized equation (Ricatti, Abell, ...)
    Thank you so much for your help!
  2. jcsd
  3. Feb 8, 2012 #2
    There might not be an analytical solution for that PDE.
  4. Feb 10, 2012 #3


    User Avatar
    Gold Member

    Are there any small parameters in the problem?

    If for example p1/p0 << 1 and p2/p0 << 1 then you might be able to find a solution using regular perturbation theory.
  5. Feb 17, 2012 #4
    How to solve a equation of this kind

    T' = a*(T^4 - r^4) + b*(T^4 - s^4) + P*(1 - eta(T))

    The above equation is driving me nuts... the 'eta' is a function of T(Temperature) and initial value of T is known.
    Say at t = 0 T is 298
    Need help! Please!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook