danong
Nov3-09, 07:08 AM
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 F = \phi\nabla\varphi - \varphi\nabla\phi,
however, i understand that \phi\nabla\varphi represents the velocity of sound vibration across the surface to an observer point.
For say, if i take \phi as Green's function and \varphi as Sound potential / pressure.
So the problem comes,
how would i understand \varphi\nabla\phi? 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 \varphi\nabla\phi?
It just seems very confusing to me,
hope someone could point out as i'm really stucked in this topic for months.
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 F = \phi\nabla\varphi - \varphi\nabla\phi,
however, i understand that \phi\nabla\varphi represents the velocity of sound vibration across the surface to an observer point.
For say, if i take \phi as Green's function and \varphi as Sound potential / pressure.
So the problem comes,
how would i understand \varphi\nabla\phi? 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 \varphi\nabla\phi?
It just seems very confusing to me,
hope someone could point out as i'm really stucked in this topic for months.