Location

La Jolla, CA

Start Date

1-1-1993 12:00 PM

Description

Nonspecular reflection, which occurs when an incident beam is phase matched to a leaky wave, is an important tool for fluid-solid interface diagnostics. A recently developed complex ray analysis for modeling nonspecular reflection of two-dimensional Gaussian sheet beams [1,2] is here extended to account for rotationally symmetric three-dimensional (3D) Gaussian beams (GBs) with arbitrary collimation. As in our 2D analysis, we utilize the complex-source-point (CSP) technique by which a conventional point-source-excited field can be converted into a 3D quasi-Gaussian beam field by displacing a real point source to a complex location [3]. When the CSP field excited in the fluid interacts with a plane or cylindrically layered elastic medium, the resulting internal and external fields can be expressed rigorously in terms of wavenumber spectral integrals that are approximated explicitly by high-frequency uniform asymptotics [4]. The resulting expressions for the reflected field contain interacting specularly reflected beam and leaky wave contributions which establish the physical basis for the observed phenomena.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

12A

Chapter

Chapter 1: Development of Standard Techniques

Section

Elastic Wave Propagation

Pages

187-194

DOI

10.1007/978-1-4615-2848-7_23

Language

en

File Format

application/pdf

Share

COinS
 
Jan 1st, 12:00 PM

Nonspecular reflection of rotationally symmetric Gaussian beams from shaped fluid-solid interfaces

La Jolla, CA

Nonspecular reflection, which occurs when an incident beam is phase matched to a leaky wave, is an important tool for fluid-solid interface diagnostics. A recently developed complex ray analysis for modeling nonspecular reflection of two-dimensional Gaussian sheet beams [1,2] is here extended to account for rotationally symmetric three-dimensional (3D) Gaussian beams (GBs) with arbitrary collimation. As in our 2D analysis, we utilize the complex-source-point (CSP) technique by which a conventional point-source-excited field can be converted into a 3D quasi-Gaussian beam field by displacing a real point source to a complex location [3]. When the CSP field excited in the fluid interacts with a plane or cylindrically layered elastic medium, the resulting internal and external fields can be expressed rigorously in terms of wavenumber spectral integrals that are approximated explicitly by high-frequency uniform asymptotics [4]. The resulting expressions for the reflected field contain interacting specularly reflected beam and leaky wave contributions which establish the physical basis for the observed phenomena.