This report presents the WKB approximation for the curvilinear horn (CH) equation, numerical comparisons of horn theories, and a model of viscothermal effects for acoustic wave propagation in axisymmetrical horns. The WKB solution is presented for the hyperbolic horn. The numerical comparisons for a hyperbolic horn profile show that the CH equations are more accurate than the plane-wave horn equation or previous spherical-wave horn equations. The CH equation using spherical coordinates has only small errors compared to the CH equation using oblate spheroidal coordinates. A variational derivation of viscothermal losses is constructed based upon the concept of wall admittance using orthogonal coordinates. The important case of the spherical-wave horn equation is considered as a special case using the first-order WKB theory. Differences from existing theory are observed near the apex of the cone.
|Original language||English (US)|
|State||Published - 1999|
ASJC Scopus subject areas
- Acoustics and Ultrasonics