A novel generalized dispersion equation to design circumferential wave fluid sensors

A novel analytical investigation of circumferential (i.e. torsional) wave propagation in long anisotropic cylindrical rod (waveguide), surrounded by a viscoelastic fluid is proposed. The material is transversely isotropic, with its symmetry axis coincident with the axial axis of the cylindrical rod. In particular, a new form of the complex dispersion equation is presented. The aim of this paper is to study the correlation between the rheological properties of the fluid and the wave characteristics (phase and attenuation). The effect of the frequency and the waveguide radius on the wave characteristics are highlighted. The obtained results show that the measurements should be performed at high frequency using small rod radius. Accordingly, the results can be serve as benchmark solutions in design of torsional wave fluid sensors.