Numerical investigation on Rayleigh-Bénard-Marangoni flow of water near the maximum density in cylindrical pools with large aspect ratios

• Published in: Journal of mechanical science and technology Vol. 36; no. 10; pp. 5291 - 5298
• Main Authors: Mo, Dong-Ming, Cao, Liu-Zhu, Zhang, Li, Ye, Shuang, Li, You-Rong
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society of Mechanical Engineers 01.10.2022
• Subjects: Control; Dynamical Systems; Engineering; Industrial and Production Engineering; Mechanical Engineering; Original Article; Vibration; Flow pattern; Cold water; Rayleigh-Bénard-Marangoni flow; Heat transfer; Density maximum
• ISSN: 1738-494X; 1976-3824
• DOI: 10.1007/s12206-022-0941-9

We report a set of direct numerical simulation results on Rayleigh-Bénard-Marangoni (R-B-M) flow of cold water in the cylindrical pools. The heat transfer between the free surface and the environment is considered. The aspect ratio Г of the cylindrical pool varies from 2 to 8. Rayleigh (Ra) and Biot (Bi) numbers are respectively confined in Ra ≤ 10 4 and 0 < Bi ≤ 50. The flow onset critical Ra is determined and the influences of Bi and the density inversion parameter ( Θ m ) on the critical Ra are analyzed. The primary bifurcation flow structures of R-B-M flow are shown and the evolution of the flow structures with Ra and Bi at different Θ m is observed. Furthermore, the heat transfer ability is estimated by Nusselt number. The results indicate that the critical Ra of the flow onset increases with increasing Bi and Θ m . But it decreases with the increase of Г . The primary bifurcation pattern is multicellular flow. With increasing Г , the number of flow cells in multicellular flow increases fast. With increasing Ra, the up-triangular and up-quadrilateral flow structures appear at Г = 4, and finally transits to the up one-torus. With increasing Ra and Г , and decreasing Θ m , average Nusselt number increases monotonically. However, with increasing Bi, it first increases, and then decreases.