Propagation and reflection of plane waves in biological tissue based on nonlocal TPL thermoelasticity

Abstract

The investigation for propagation and reflection of plane waves is carried out based on three-phase-lag (TPL) thermoelasticity with the aids of Eringen's nonlocal theory in a special medium - biological tissue. The scalar and vector potential functions of Helmhotz decomposition are adopted to obtain the propagation speeds, attenuation coefficients and reflection coefficients of plane waves analytically. There are two sets of dispersive attenuated longitudinal waves whose speeds of propagation are associated with angular frequency, and independent transverse elastic shear wave which exhibits no attenuation. It is found that the blood perfusion rate has few effects on wave propagation speed and attenuation coefficient and the phase lag of temperature gradient is negligible in present configuration. The effects of working angular frequency, nonlocal parameters, phase lag times, reflecting thermal boundaries and the type of incident waves on the propagation speeds, attenuation coefficients and reflection coefficients of harmonic waves are discussed and investigated graphically.