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

Green's Function - Kirchoff Helmholtz Integral Problem

  1. Nov 3, 2009 #1
    I'm seeking help in understanding Kirchoff-Helmholtz Integral.

    Actually what i am facing the problem here is,
    i don't understand certain things about Green's 2nd identity which stated that two scalar function can be interchanged,
    and forming the force [tex]F = \phi\nabla\varphi - \varphi\nabla\phi[/tex],

    however, i understand that [tex]\phi\nabla\varphi[/tex] represents the velocity of sound vibration across the surface to an observer point.

    For say, if i take [tex] \phi [/tex] as Green's function and [tex] \varphi [/tex] as Sound potential / pressure.

    So the problem comes,
    how would i understand [tex]\varphi\nabla\phi[/tex]? distribution of sound pressure with impulse unit at the observer point?
    Then why do i need to subtract it ?
    Are they equivalent?

    How does reciprocal theorem applies here at the [tex]\varphi\nabla\phi[/tex]?
    It just seems very confusing to me,
    hope someone could point out as i'm really stucked in this topic for months.
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted