This book represents the HELS (Helmholtz equation least squares) theory and its applications for visualizing acoustic radiation from an arbitrarily shaped vibrating structure in free or confined space. It culminates the most updated research work of the author and his graduate students since 1997. The book contains six chapters. The first serves as a review of the fundamentals in acoustics and the rest cover five specific topics on the HELS theory.

This book is written for those who want to learn the state-of-the-art technology on visualizing acoustic radiation from vibrating objects, to understand difficulties involved in these inverse acoustic problems, and to acquire the information necessary to conduct successful vibro-acoustic diagnostics on their own. Attention is focused on the new development on nearfield acoustical holography (NAH) beyond the traditional Fourier acoustics that are suitable for separable geometries only. Specifically, it presents:

-Helmholtz equation least squares (HELS) method

-inverse...