# Numerical analysis of the bifurcation point sensibility to the temperature field in the Taylor-Couette flow

## Palavras-chave:

Taylor-Couette, CFD, Bifurcation## Resumo

The flow between concentric cylinders, called Taylor-Couette flow, has been extensively studied during

last century in works describing its governing parameters and presenting the various flow regimes for each con-

figuration. This kind of flow is present in the air gap of electrical machines and its characteristics affect the heat

transfer and the torque generated on the outer cylinder due viscous forces. The intensity of these effects depends

on the flow state, which is governed by geometric characteristics and Reynolds number. Our objective is to analyze

the effect of heat transfer on the surging wavy vortex and on the torque generated at outer cylinder. The numerical

simulations are done using the software OpenFOAM v9 with K-Omega SST as the main turbulence model. All

the simulations were in the transient regime. The pisoFoam solver was employed for the isothermal problem and

for the buoyantPimpleFoam solver for the thermal problem. A mesh independence study was done based on Grid

Convergence Index (GCI) method, where we found satisfactory values. For the thermal cases, we analyzed the

behavior of the flow as we increase the Reynolds number and the temperature at the walls, comparing its results

with the isothermal. It is notable the delay in the formation of the wavy vortices comparing with the rotational

speed and the decrease of the torque on the external wall.