Time-dependent states in the Weissenberg effect

Experiments characterizing time-dependent states in the Weissenberg effect in First Brand Corporation's STP™ oil additive are described. The Weissenberg effect is the climbing of a rotating rod by a viscoelastic fluid. The results of a general survey of the states found with varying rod diameter, fluid height, and fluid temperature are presented. A detailed examination is made of the sequence of states found with a particular rod diameter and fluid depth. In this case, the Weissenberg effect is shown to exhibit characteristics of the Ruelle-Takens route to chaotic flow. In this case, the flow undergoes successive bifurcations from a time independent state to states with one frequency, two frequencies, three frequencies and then chaos, characteristic of the Ruelle-Takens route to chaos.