Abstract
Flow-birefringence technique using a suspension of milling yellow dye in water is applied to low-Reynolds-number flow around the following obstacles:(l) a circular cylinder, (2) two circular cylinders in a line with uniform flow, (3) an isolated sphere, and (4) a pair of spheres in a line with uniform flow. Photographs of isochromatics and of isoclinics are analyzed to obtain streamlines around the above-described obstacles. These results show the validity of Oseen approximation for uniform flow around these obstacles at low Reynolds numbers. Numerical calculations of streamlines around a pair of spheres, described in the appendix, show the details of closed vortex regions between a pair of spheres.
