The International Conference on Multiphase Systems, ICMS'2000
|The Effect of Sound on Viscoelastic Properties of Oils|
Esipov&npsp;I.&npsp;B., Mironov&npsp;M.&npsp;A., Pirogov&npsp;V.&npsp;A., Zozulya&npsp;O.&npsp;M.
Andreyev Acoustics Intitute, Moscow, RUSSIA
Chelintsev N. S.
Gubkin Oil and Gas State University, Moscow, RUSSIA
Many inhomogeneous liquids reveal the property of viscosity variation under shear stress, displaying at the same time viscoelastic behavior. The viscosity of these so called non-Newtonian liquids usually decreases with increase in the shear stress and as a result the medium slips along a smooth surface. Crude oil is proved to be a real non-Newtonian liquid. Two examples of experimental investigation of sound effect on the oil shear viscosity are considered in the paper. The first one shows a new nonlinear acoustics process in a confined Non-newtonian liquid - stimulated acoustical transparency of oil in a thin capillary as a waveguide, and the second one demonstrates the effect of acoustical liquefaction of frozen crude oil in a pipe. Effects under discussion may belong to a wide class of instabilities arising in dynamical systems, and be interpreted similarly to the models of the earthquake fault dynamics.