Simulation of Ultrasonic Imaging with Linear Arrays in Causal Absorptive Media

Simulation of Ultrasonic Imaging with Linear Arrays in Causal Absorptive Media

Simulation of Ultrasonic Imaging with Linear Arrays in Causal Absorptive Media

Rigorous and efficient numerical methods are presented for simulation of acoustic propagation in a medium where the absorption is described by relaxation processes. It is shown how FFT-based algorithms can be used to simulate ultrasoun,d images in pulse-echo mode. General expressions are obtained for the complex wavenumber in a relaxing medium. A fit to measurements in biological media shows th...

Simulation of ultrasonic imaging with linear arrays in causal absorptive media.

Rigorous and efficient numerical methods are presented for simulation of acoustic propagation in a medium where the absorption is described by relaxation processes. It is shown how FFT-based algorithms can be used to simulate ultrasound images in pulse-echo mode. General expressions are obtained for the complex wavenumber in a relaxing medium. A fit to measurements in biological media shows the...

Stability of Temporally-Evolving Supersonic Boundary Layers over Micro-Cavities for Ultrasonic Absorptive Coatings

Ultrasonic absorptive coatings, consisting of regularly-spaced arrays of micro-cavities, have previously been shown to effectively damp second-mode instability for the purpose of delaying transition in hypersonic boundary layers. However, previous simulations and stability analysis have used approximate porous-wall boundary conditions. Here we investigate the feasibility of using direct numeric...

Simulation of B-scan images from two-dimensional transducer arrays: Part II--Comparisons between linear and two-dimensional phased arrays.

Two-dimensional (2-D) arrays have been proposed as a solution to the degradation in medical ultrasound image quality occurring as a result of asymmetric focusing properties of linear phased array transducers. The 2-D phased transducer array is also capable of electronically steering the symmetrically focused ultrasound beam throughout a three-dimensional volume. In a companion paper the potenti...