title: Verification of the Westervelt equation for focused transducers.
abstract: This study investigates the validity of the Westervelt equation for focused transducers. The angular spectrum method is employed to analyze the second-harmonic acoustic field under the weakly nonlinear approximation. Although it is well known that the Westervelt equation is accurate for the case of quasi-plane waves, the present work demonstrates accurate solution for the highly focused case of a spherically-curved ultrasound transducer having an aperture angle of 80°. It is further found that the solution error is inversely dependent on the nonlinearity coefficient.
authors.forename: Yun
authors.initials: Y
authors.lastname: Jing
authors.forename: Du
authors.initials: D
authors.lastname: Shen
authors.forename: Greg T
authors.initials: GT
authors.lastname: Clement