Streaming Birefringence as a Hydrodynamic Research Tool

Citation

Sutera, Salvatore Philip (1960) Streaming Birefringence as a Hydrodynamic Research Tool. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/DDJZ-7X80. https://resolver.caltech.edu/CaltechETD:etd-07062006-080514

Abstract

An optical system capable of providing precise pointwise measurements of streaming birefringence (SBR) was used to explore the flow of dilute solutions of tobacco mosaic virus between rotating eccentric cylinders. The local relationship between the observed optical anisotropy and the rate of strain tensor calculated from the theoretical solution for the particular flow field was studied. The relationship is apparently in accord with the conclusions of the orientation theory for a sufficiently dilute solution of rigid macromolecules in generalized two-dimensional flow. The general problem of using streaming birefringence of colloidal solutions to visualize two-dimensional laminar flows is considered. The conclusion is reached that a clear and unambiguous kinematic interpretation of SBR in such fluids is possible only for a restricted class of flows. If the flow is such that the angle between the streamline and the principal rate of strain axes is not less than 35°, then to a good approximation SBR can give the magnitude and direction of the principal strain rates. This information, it is shown, is sufficient to permit calculation of the entire velocity field if the velocity is known on all boundaries. In the most general flow situations, SBR of colloidal solutions cannot indicate the orientation of the rate of strain tensor. SBR in certain birefringent pure liquids may yield the necessary information even in the most general flows. These pure liquids hold promise of being valuable flow visualization agents.

Thesis Files