Artículo
Global stability analysis of the natural convection between two horizontal concentric cylinders
Autor/es | Serrano Aguilera, J.J.
Blanco Rodríguez, Francisco Jose Parras, L. |
Departamento | Universidad de Sevilla. Departamento de Ingeniería Aeroespacial y Mecánica de Fluidos |
Fecha de publicación | 2021 |
Fecha de depósito | 2022-09-13 |
Publicado en |
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Resumen | In this investigation, the 2D flow between two horizontally positioned concentric cylinders (gravity perpendicular to the axis of the cylinders), where the inner cylinder is kept at constant temperature Ti higher
than the ... In this investigation, the 2D flow between two horizontally positioned concentric cylinders (gravity perpendicular to the axis of the cylinders), where the inner cylinder is kept at constant temperature Ti higher than the outer border temperature To, is analyzed. Buoyancy forces initiate the movement of the fluid and the generated flow is studied in a fixed geometry for values of Prandtl numbers (Pr) between 0.01 and 1, and Rayleigh numbers (Ra) between 102 and 5 · 106. To solve the problem, a Chebyshev-Fourier spectral code is developed in polar coordinates (r, θ ) respectively, and a complete map of steady-state solutions is obtained where regions with multiple solutions are identified. Later, a global stability study of the obtained stationary solutions is carried out, providing a transition curve to unstable areas as a function of the control parameters of the problem (Pr, Ra). Finally, to check the stability results, temporal evolution simulations are accomplished for several cases where dual solutions are presented, finding intermediate almost stationary solutions, and demonstrating that there exist typically single oscillating plume or double oscillating plume solutions (depending on the parameter space), where some of them have higher heat transfer coefficients, which may be interesting alternatives to improve heat exchange systems by means of passive control techniques. |
Identificador del proyecto | FJCI-2017-32403
IJCI-2016-30126, UMA18-FEDERJA-195 |
Cita | Serrano Aguilera, J.J., Blanco Rodríguez, F.J. y Parras, L. (2021). Global stability analysis of the natural convection between two horizontal concentric cylinders. International Journal of Heat and Mass Transfer, 172, Article number 121151. |
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