# The Stability of Spiral Flow Between Rotating Cylinders

S. Chandrasekhar

## Abstract

The stability of viscous flow under an axial pressure gradient between two co-axial cylinders rotating in the same direction is considered. The critical Taylor number (T$_c$) for the onset of instability is then a function of the Reynolds number (R) of the mean axial flow. A perturbation theory valid in the limit R $\rightarrow$ 0 is developed and the formula $T_c(R) = T_c(0) + 26\cdot 5R^2 (R \rightarrow 0)$ is established.