A Influência de escoamento não isotérmico na instabilidade de Taylor-Couette através de análise numérica

Abstract

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.