## 3aSPb6. A novel numerical method for analyzing 1.5- and 2-dimensional ultrasound arrays.

### Session: Wednesday Morning, December 4

### Time: 9:15

**Author: Richard E. Morrow**

**Location: Skyblue Systems, 1223 Peoples Ave., Troy, NY 12180**

**Author: Gary Bedrosian**

**Location: Skyblue Systems, 1223 Peoples Ave., Troy, NY 12180**

**Abstract:**

A novel numerical technology based on finite-element methods has been
developed for analyzing interaction problems in 1.5- and 2-D ultrasound arrays.
A standard finite-element array model consists of structural elements encased in
fluid. For accurate solutions, a portion of the fluid must be meshed and
truncated with a radiation boundary condition which approximates an infinite
domain. The essence of this new technology, termed overlapping grid, is that
only the structural elements will actually be meshed. The surrounding air or
water is automatically created as a uniform cubic mesh which is invisible to the
user and properly connected to the structural mesh. In addition to obvious
advantages for mesh creation, larger numerical models can be solved. For a
hypothetical 3-D acoustic model where ten are structural and the rest fluid, the
total storage required using the overlapping grid technology is one third of
that required using the current finite-element storage techniques. The
overlapping grid technology also results in a significant speedup in the most
time-consuming part of an iterative solver algorithm, which is multiplication of
a vector by the stiffness matrix.

ASA 132nd meeting - Hawaii, December 1996