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3dimensional wave propogation.

  1. Feb 19, 2013 #1
    I thought the maths area would be the best place to ask..

    What kind of function would represent a 3 dimensional sine wave?
    A sine wave, where the z-axis lays on the circumference of a circle.
     
  2. jcsd
  3. Feb 19, 2013 #2

    berkeman

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    Staff: Mentor

    What is the context of the question? The equation for a symmetric longitudinal wave in 3-D is straightforward, I think. But I'm not sure there is a solution for symmetric transverse waves in 3-D...
     
  4. Feb 19, 2013 #3
    Essentially, the function for this:
    sinani2.gif

    There isn't really a context, I'm not currently studying anything relating to this, it just interests me to see the behaviour of waves.

    I seem to have found it, by looking for an example image.
    z = sinx(√(x2+y2))
     
  5. Feb 19, 2013 #4

    berkeman

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    Staff: Mentor

    Oh, I misunderstood your question then. I thought you wanted it to be symmetric in 3 dimensions, not just 2.
     
  6. Feb 19, 2013 #5
    Actually, that would be interesting..

    Thank you for the assistance though. ^_^
     
  7. Feb 20, 2013 #6
    Just solve the wave equation in three dimensions, if you are only interested in isotropic propogation then set all the angular derivatives to zero.
     
  8. Feb 27, 2013 #7

    jasonRF

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    I think like others I am not certain what the OP really meant, but I interpreted the question this way too - perhaps because I have a general interest in waves. Anyway, an example of a 3D plane wave would be:
    [tex]
    f(x,y,z,t) = \sin\left(k_x x + k_y y + k_z z - \omega t \right)
    [/tex]
     
  9. Feb 27, 2013 #8

    olivermsun

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    The axisymmetric 2d wave is of interest in surface wave propagation from a point source. There you examine sin (kr-ωt) where r= sqrt(x^2 + y^2).

    The radially symmetric 3d wave arises for acoustic (pressure) waves emanating from a point source. The relevant plane wave has the form sin (kr - ωt) for r = sort(x^2 + y^2 + z^2) as jasonRF states above.
     
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