The influence of non-isothermal flows in the Taylor-Couette instability through numerical analysis

Resumo

The Taylor-Couette flow is a classic rotational flow studied since the beginning of the 20th century. The
phenomenon occurs in the gap between two cylinders with different rotational velocities. It happens when one of
the cylinders, usually the inner one, has a rotation that causes centrifugal forces higher than the viscous forces.
The most recognizable characteristic of the flow is the Taylor vortex, an eddy-like pattern that appears across
the cylinders length. The present simulation of Taylor-Couette in the gap inside an electric machine considers
an aspect ratio air gap - cylinder length of 1:20 and the radius rate of 0.9859. The present work evaluates the
necessary rotation, under the geometric conditions presented, to form the Taylor vortices in isothermal flow and
when the flow is submitted to temperature gradients. The GCI method is used to validate the grid dependency. We
have observed and discussed the sensibility of temperature gradients to the identification of the critical flow, to the
velocity field and to the torque at the outer cylinder.