### ASA 124th Meeting New Orleans 1992 October

## 3pSA2. Acoustic harmonic radiation from cylinders using a new internal
source density method.

**Peter R. Stepanishen
**

**
Sudheer Ramakrishna
**

**
**
*Dept. of Ocean Eng., Univ. of Rhode Island, Kingston, RI 02881
*

*
*
Two-dimensional acoustic harmonic radiation from cylinders which are
symmetric about an axis and vibrating with a specified normal velocity is
addressed using a new internal source density approach. The approach is based
on the use of internal monopole and dipole source density line distributions
along the axis of symmetry of the cylinder. A least-mean-square error method is
used to determine the source distributions by matching the normal velocity of
the cylinder to the normal velocity field of the source distributions at the
cylindrical surface. The surface pressure and exterior pressure field are
readily obtained from the source distributions. Discretization of the resultant
line integrals leads to sets of linear algebraic equations which are readily
solved for the monopole and dipole source strengths. Numerical results are
presented to illustrate the accuracy of the method for the case of circular and
elliptical cylinders subjected to various specified continuous and
discontinuous normal velocity boundary conditions and frequencies.