Abstract:
This thesis investigates hydrodynamic and thermal instabilities in a Taylor-Couette system subjected to differential heating, analyzing the influence of geometric parameters and rotational conditions of the cylinders across four distinct configurations. An in-depth review of previous studies provides context on the main flow regimes and commonly used modeling approaches. The mathematical formulation is based on the conservation equations of mass, momentum, and energy, with appropriate boundary conditions and control parameters influencing the flow. The numerical resolution is carried out using the finite volume method combined with the SIMPLER algorithm, ensuring accurate simulation of the flow behavior. The results, validated by comparison with literature data, highlight the impact of rotation and heating parameters on regime transitions and instability structures. For the Rotor-Stator configuration, no inclination effect is observed, whereas it plays a crucial role in mixed convection. Moreover, the horizontal position is recommended from a thermal perspective, ensuring efficient heat transfer. Additionally, increasing the speed ratio enhances thermal exchange and alters the flow structure, albeit differently depending on the relative rotation direction of the cylinders. As such, corotation emerges as the optimal choice for achieving dynamic and thermal stability in both forced and mixed convection. Although the counterrotating configuration offers the highest mixing level and rapid thermal homogenization, the turbulent flow potential may not be suitable for all industrial applications.
