Fractional telegraph equation under moving time-harmonic impact

Int J Heat Mass Transf. 2022 Jan:182:121958. doi: 10.1016/j.ijheatmasstransfer.2021.121958. Epub 2021 Sep 20.

Abstract

The time-fractional telegraph equation with moving time-harmonic source is considered on a real line. We investigate two characteristic versions of this equation: the "wave-type" with the second and Caputo fractional time-derivatives as well as the "heat-type" with the first and Caputo fractional time-derivatives. In both cases the order of fractional derivative 1 < α < 2. For the time-fractional telegraph equation it is impossible to consider the quasi-steady-state corresponding to the solution being a product of a function of the spatial coordinate and the time-harmonic term. The considered problem is solved using the integral transforms technique. The solution to the "wave-type" equation contains wave fronts and describes the Doppler effect contrary to the solution for the "heat-type" equation. Numerical results are illustrated graphically for different values of nondimensional parameters.

Keywords: Caputo derivative; Fourier transform; Fractional calculus; Laplace transform; Telegraph equation; Time-harmonic impact.