Boundary layers in turbulent vertical convection at high Prandtl number. (10th January 2022)

• Record Type: Journal Article
• Authors: Howland, Christopher J.; Ng, Chong Shen; Verzicco, Roberto; Lohse, Detlef
• Is Part Of: Journal of fluid mechanics. Volume 930(2022)
• Publication Date: 2022-01-10
• Subjects: turbulent convection -- turbulent boundary layers -- buoyant boundary layers; Fluid mechanics -- Periodicals; 532.005
• DOI: 10.1017/jfm.2021.952
• Languages: English
• ISSNs: 0022-1120

Abstract

Abstract: Abstract : Many environmental flows arise due to natural convection at a vertical surface, from flows in buildings to dissolving ice faces at marine-terminating glaciers. We use three-dimensional direct numerical simulations of a vertical channel with differentially heated walls to investigate such convective, turbulent boundary layers. Through the implementation of a multiple-resolution technique, we are able to perform simulations at a wide range of Prandtl numbers ${Pr}$ . This allows us to distinguish the parameter dependences of the horizontal heat flux and the boundary layer widths in terms of the Rayleigh number $\mbox {{Ra}}$ and Prandtl number ${Pr}$ . For the considered parameter range $1\leq {Pr} \leq 100$, $10^{6} \leq \mbox {{Ra}} \leq 10^{9}$, we find the flow to be consistent with a 'buoyancy-controlled' regime where the heat flux is independent of the wall separation. For given ${Pr}$, the heat flux is found to scale linearly with the friction velocity $V_\ast$ . Finally, we discuss the implications of our results for the parameterisation of heat and salt fluxes at vertical ice–ocean interfaces.