Onset of Absolute Instability Induced by Viscous Dissipation in the Poiseuille-Darcy-Benard Convection of a Newtonian Fluid

32nd UIT (Italian Union of Thermo–fluid-dynamics) Heat Transfer Conference

物理学;力学

Brandão, P.V.^1 ; Alves, L. S. De B.^1 ; Barletta, A.^2

Programa de Pós-Graduação em Engenharia Mecânica, Universidade Federal Fluminense, Rua Passo da Pátria 156, Bloco E, São Domingos, Niterói, RJ

24210-240, Brazil^1

Dipartimento di Ingegneria Industriale, Alma Mater Studiorum Università di Bologna, Viale Risorgimento 2, Bologna

I-40136, Italy^2

关键词: Absolute instability;    Cross flows;    Newtonian fluids;    Rayleigh number;    Viscous dissipation;    Weak cross-flow;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/547/1/012039/pdf
DOI  :  10.1088/1742-6596/547/1/012039

学科分类：力学，机械学

来源: IOP

【 摘 要 】

The present paper investigates the transition from convective to absolute instability induced by viscous dissipation. As far as the authors are aware, this is the first time such a study is reported in the literature. Its framework is provided by the Poiseuille-Darcy-Benard convection of a Newtonian fluid. We found the same behaviour observed in the absence of viscous dissipation whenever the Gebhart number is smaller than Ge4.31, the cross flow always destabilises this onset. The latter two conditions create a scenario where viscous dissipation is capable of inducing a transition to absolute instability in the absence of wall heating, i.e. with a zero Rayleigh number.