caa a22 4500 606166920 CHVBK 20210128100700.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s10665-014-9745-y doi (NATIONALLICENCE)springer-10.1007/s10665-014-9745-y Onset of thermal convection in a porous layer with mixed boundary conditions [Elektronische Daten] [Antonio Barletta, Peder Tyvand, Heidi Nygård] Stability of a horizontal porous layer saturated by a fluid under conditions of heating from below is revisited. The aim is to extend the model for the boundary walls constraining the velocity and temperature by means of mixed, or third-kind, conditions. This model proved to be appropriate to describe departure from perfectly conducting or uniform heat flux conditions for the temperature, and impermeable or perfectly permeable conditions for the velocity. Linearised equations for general normal modes perturbing the basic rest state are obtained. The principle of exchange of stabilities is proven. The perturbation equations are solved analytically to deduce the dispersion relation at neutral stability, as well as to draw neutral stability curves and to yield the critical values of the Darcy-Rayleigh number and of the wave number for the onset of the instability. Specially interesting regimes are analysed in detail including the degenerate case, where the velocity and temperature boundary conditions feature the same mixing parameters, and the symmetric case, where identical conditions are prescribed on both boundaries. Springer Science+Business Media Dordrecht, 2014 Darcy-Bénard problem nationallicence Darcy's law nationallicence Mixed boundary conditions nationallicence Porous layer nationallicence Thermal instability nationallicence Barletta Antonio Department of Industrial Engineering, Alma Mater Studiorum Universitá di Bologna, Viale Risorgimento 2, 40136, Bologna, Italy aut Tyvand Peder Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, 1432, Ås, Norway aut Nygård Heidi Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, 1432, Ås, Norway aut Journal of Engineering Mathematics Springer Netherlands 91/1(2015-04-01), 105-120 0022-0833 91:1<105 2015 91 10665 https://doi.org/10.1007/s10665-014-9745-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10665-014-9745-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Barletta Antonio Department of Industrial Engineering, Alma Mater Studiorum Universitá di Bologna, Viale Risorgimento 2, 40136, Bologna, Italy aut NATIONALLICENCE 700 1- Tyvand Peder Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, 1432, Ås, Norway aut NATIONALLICENCE 700 1- Nygård Heidi Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, 1432, Ås, Norway aut NATIONALLICENCE 773 0- Journal of Engineering Mathematics Springer Netherlands 91/1(2015-04-01), 105-120 0022-0833 91:1<105 2015 91 10665