This is the third in a series of our study of Rayleigh-Bénard convection at large Prandtl number. Here we investigate whether stationary statistical properties of the Boussinesq system for Rayleigh-Bénard convection at large Prandtl number are related to those of the infinite Prandtl number model for convection that is formally derived from the Boussinesq system via setting the Prandtl number t...

We present the results of direct numerical simulations power spectral densities for kinetic energy, convective entropy and heat flux unsteady Rayleigh-B\'{e}nard magnetoconvection in frequency space. For larger values frequency, all global quantities vary with $f$ as $f^{-2}$. The scaling exponent is independent Rayleigh number, Chandrasekhar's number thermal Prandtl number.

A new upper bound on the rate of vertical heat transport is established in 3 dimensions for stress-free velocity boundary conditions on horizontally periodic plates. For large (but finite) Prandtl numbers this bound is an improvement over the ‘ultimate’ Ra scaling and in the limit of infinite Pr, agrees with the bound of Ra recently derived in that limit. keywords: Rayleigh-Bénard convection, B...

Natural convective laminar flow is numerically investigated in a two-dimensional and square enclosure at various angles of inclination respect to horizontal. Two adjacent walls of the enclosure are insulated and the other two are kept at different temperatures. The influence of Rayleigh number representing the effects due to the differential heating of the enclosure walls as well as the effect ...

In this study, the effects of Prandtl number on the primary and secondary instability of the Rayleigh-Benard convection problem has been investigated using the lattice Boltzmann method. Two different cases as Pr=5.8 and 0.7 representing the fluid in liquid and gas conditions are examined. A body forces scheme of the lattice Boltzmann method was presented. Two types of boundary conditions in the...

The buoyancy-driven fluid flow and heat transfer in a square cavity with partially active side walls filled with Cu-water nanofluid is investigated numerically. The active parts of the left and the right side-walls of the cavity are maintained at temperatures Th and Tc, respectively, with Th>Tc. The enclosure’s top and bottom walls, as well as, the inactive parts of its side walls are kept insu...

The main objective of this research is to analyze optimization and the thermal performance of circular porous fins with four different profiles, rectangular, convex, triangular and concave under fully wet conditions. In this research, a linear model was used for the relationship between humidity and temperature. Also, modeling is assumed one-dimensional and the temperature changes only in the d...

Natural convection heat transfer in a square enclosure with a horizontal baffle at the centerline of the left wall containing Al2O3-water in the presence of a magnetic field is investigated numerically. The top and bottom horizontal walls are adiabatic. The left wall and the baffle are maintained in constant temperature Th and the right wall is maintained in...

By JESSE OTERO, LUBOMIRA A. DONTCHEVA, HANS JOHNSTON, RODNEY A. WORTHING, ALEXANDER KURGANOV, GUERGANA PETROVA AND CHARLES R. DOERING 3,7 Department of Mathematics, Ohio State University, Columbus, OH 43210, USA Department of Computer Science & Engineering, University of Washington, Seattle, WA 98195-2350, USA Department of Mathematics, University of Michigan, Ann Arbor, MI 48109-1109, USA Brea...