Dispersion and Sensitivity Analysis of Quasi-Scholte Wave Liquid Sensing by Analytical Methods

Ultrasonic-guided wave sensing relies on perturbation of wave propagation by changing physical properties of the target media. Solid waveguides, through which guided waves can be transduced between the transducer and the target media, are frequently employed for liquid sensing and several other applications. In this manuscript, liquid sensing sensitivity of dispersive quasi-Scholte waves, which are guided interface waves that travel at the solid-liquid boundary, is investigated. Dispersion analysis of quasi-Scholte waves is done and sensitivities of quasi-Scholte waves to changes in fluid density and speed of sound in a dipstick configuration are analyzed. An experimentally verified analytical model based on a global matrix approach is employed in a nondimensional manner to generate representative dispersion and sensitivity surfaces. Optimum configurations with respect to the material properties of the liquid and of the waveguide are illustrated, which would enable optimal quasi-Scholte liquid sensing.