Measurement of the shear storage modulus and viscosity of liquids using the Bleustein–Gulyaev wave

Abstract

In the article, a method for measuring the rheological properties of viscoelastic liquids using the (surface shear) Bleustein–Gulyaev (B–G) wave is presented. By applying the perturbation method, one can prove that the change in the complex propagation constant of the B–G wave produced by the layer of viscoelastic liquid loading the waveguide surface is proportional to the shear acoustic impedance of the liquid. From the analysis performed by the authors, it results that the sensitivity of the B–G wave method used to determine the rheological parameters of the liquid is even higher than the sensitivity of the Love wave method. In this article, a practical measuring setup employing the B–G wave for the purpose of measuring the rheological properties of the liquid is presented. Subsequently, by measuring the change in the velocity and attenuation of the B–G wave, the shear impedance of the liquid was evaluated. Knowledge of the shear impedance of the investigated liquid then made it possible to calculate, for a given rheological model, the shear storage modulus μ and viscosity η of the investigated liquid. Measurements of liquid viscosity performed using the B–G wave method were compared to those obtained from the static capillary (Ubbelohde) method.

New ultrasonic Bleustein-Gulyaev wave method for measuring the viscosity of liquids at high pressure

“…[11][12][13] The energy of these waves is concentrated in the vicinity of the surface being in contact with a measured liquid. In consequence, the sensitivity of the viscosity sensors using shear surface acoustic waves can be several orders larger than the sensitivity of the sensors employing bulk shear acoustic waves.…”

Application of Acoustic Waves to Investigate the Physical Properties of Liquids at High Pressure

“…The liquid presented on the waveguide surface loads it mechanically. The value of this load is proportional to the value of the mechanical impedance Z L of a liquid medium (Kiełczyński et al, 2004). The mechanical impedance of a layer of liquid loading the surface of the SH surface wave (i.e., Love or B-G wave) waveguide is equal to the characteristic shear impedance of the liquid Z L for plane waves:…”

“…Hence, in the metallized surface condition the B-G wave is more sensitive to liquid loading. B-G waves are excited similarly as Love waves, using the plate transducer (Kiełczyński et al, 2004) The Love wave is a dispersive wave (i.e., the phase velocity is dependent on frequency) and can exhibit higher waveguide modes than fundamental one. By contrast, the B-G wave is a nondispersive wave.…”

High pressure changes of the castor oil viscosity by ultrasonic method

“…One can prove that the change in the complex propagation constant γ of the B-G wave produced by viscoelastic liquid loading is as follows [14,15]:…”

“…Temperature was measured by the copper -constantan thermocouple placed inside the chamber. For measuring viscosity using B-G wave [15], the sending -receiving piezoelectric transducer was driven by the TB-1000 pulser -receiver computer card. The B-G wave impulse generated by this transducer was reflected in multiple ways between two opposite edges of the piezoceramic waveguide.…”