## 5pSA11. Explicit solution to the Kirchhoff integral formulation.

### Session: Friday Afternoon, May 17

### Time: 4:35

**Author: Sean F. Wu**

**Author: Qiang Hu**

**Location: Dept. of Mech. Eng., Wayne State Univ., Detroit, MI 48202**

**Abstract:**

An explicit solution to the Kirchhoff integral formulation for predicting
acoustic radiation from a vibrating object is derived. The radiated acoustic
pressure is shown to be expressible in terms of integrations of the normal and
tangential components of the particle velocity over a surface that encloses the
object. If this surface coincides with that of the vibrating object, then the
normal component of the particle velocity is equal to that of the surface
velocity, which is normally assumed given. The tangential component of the
particle velocity, however, is different from that of the surface velocity, but
is determinable experimentally by using an intensity probe. For a class of
special cases in which the object dilates uniformly, the tangential component of
the particle velocity is identically zero. Under this condition, the radiated
acoustic pressure can be obtained by directly integrating the normal component
of the surface velocity over the vibrating surface, rather than solving the
surface acoustic pressure first, and then the radiated acoustic pressure, as it
is traditionally done in the numerical solutions to the Kirchhoff integral
formulation.

from ASA 131st Meeting, Indianapolis, May 1996