Nonlinear ultrasound simulations including complex frequency dependent attenuation

Autores UPV
Año
CONGRESO Nonlinear ultrasound simulations including complex frequency dependent attenuation

Abstract

Including non-squared frequency dependent attenuation is essential to obtain accurate acoustic predictions in biological media when wide-band signals and/or nonlinear effects are taking into account. Thus, a time domain nonlinear acoustics model is present, where the dispersion and attenuation is included by means of relaxation processes. In this way, an efficient implementation by finite differences avoiding convolutional operators is developed. By optimizing a pair of relaxing parameters the model exhibit an attenuation frequency response that fits a power law experimental data for most biological tissues. In this way, is possible to obtain arbitrary frequency dependent attenuation and dispersion in order to model biological media. Furthermore, due to the generalized formulation, typical relaxation processes can be modeled as the observed in air or seawater, and model the losses of longitudinal waves observed in other complex heterogeneous media as soil or porous rock.