Physics:Kirchhoff–Helmholtz integral

The Kirchhoff–Helmholtz integral combines the Helmholtz equation with the Kirchhoff integral theorem to produce a method applicable to acoustics, seismology and other disciplines involving wave propagation. It states that the sound pressure is completely determined within a volume free of sources, if sound pressure and velocity are determined in all points on its surface.

$\mathit{P}(w,z)=\underset{dA}{\iint }(G(w,z|z^{\prime })\frac{\partial }{\partial n}P(w,z^{\prime })-P(w,z^{\prime })\frac{\partial }{\partial n}G(w,z|z^{\prime }))d{z}^{\prime }$

See also

• Kirchhoff integral