The Measurement of Flow Anisotropy in Pure Liquids

Abstract

In a previous paper (Champion 1958) a calculation was made of the optical anisotropy due to shearing a simple liquid. A coaxial cylinder apparatus suitable for the measurement of the streaming birefringence of pure liquids at very high velocity gradients (50 000 sec-1) was constructed in order to test this calculation experimentally. A new experimental technique to enable a weak birefringence to be measured was developed, the liquid being sheared for the shortest possible time (similar 10 sec), so that the heating effects within the liquid were negligibly small. Measurements on ethyl cinnamate, chloroform and carbon tetrachloride are described and for the tetrahedral molecule (CCl4) there is a favourable agreement between experiment and theory. This agreement shows that the assumptions made and the conclusions drawn in the previous paper are reasonable.