Bifurcation phenomena in steady flows of a viscous fluid II. Experiments

Abstract

Abstract The experimental work is concerned with several phenomena studied theoretically in part I (Benjamin 1977). Observations on Taylor-vortex flows between cylinders of comparatively small but variable length are reported, revealing properties unexplained by older theories. The observed flows are classified as follows: (i) the primary mode which is uniquely possible at small values of the Reynolds number R, and which usually develops smoothly with increasing R; (ii) secondary modes which are possible only above a respective critical value of R, and which are shown to manifest predicted behaviour as this value is approached from above (§4). Two novel and surprising examples of (ii) are reported. A predicted hysteresis phenomenon is confirmed, relating to morphogenesis of the primary mode between two-cell and four-cell forms as the length of the annulus is varied (§5). The experimental results are discussed from a theoretical standpoint in §6.