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 report the first definitive Nusselt number scale of thermal boundary layers from curved surfaces characterized by proposed non-dimensional curvature parameter ξ = R0/(HRa−1/4), where R0 denotes radius a surface, H corresponding finite height, and Ra global Rayleigh virtual reference layer on vertical flat surface. The is given Nu ∼ ξ−1/5Ra1/4 in which Ra1/4 for surface case, revealing that c...

Penetrative turbulence, which occurs in a convectively unstable fluid layer and penetrates into an adjacent, originally stably stratified layer, is numerically theoretically analyzed. We chose the most relevant example, namely thermally driven flow of water with temperature around $T_m\approx 4^\circ\rm{C}$, where it has its density maximum. pick Rayleigh-B\'enard geometry bottom plate $T_b > 4...

Numerical simulation reported on heat transfer and fluid flow in a two-dimensional rectangular micro channel totally filled with Ag/water. The first –order slip/jump boundary conditions were uniformly imposed to the up bottom walls. governing conservation equations are translated dimensionless form using thermal Single Relaxation Time (T-SRT) modified Lattice Boltzmann Method (LBM) double distr...

The RANS method with Saffman’s turbulence model was employed to solve the time-dependent turbulent Navier-Stokes and energy equations for oscillating pipe flows. The method of partial sums of the Fourier series is used to analyze the harmonic velocity and temperature results. The complete structures of the oscillating pipe flows and the averaged Nusselt numbers on the tube wall are provided by ...

Non-uniform heat flux generated by microchips causes “hot spots” in very small areas on the microchip surface. These hot spots are generated by the logic blocks in the microchip bay; however, memory blocks generate lower heat flux in contrast. The goal of this research is to design, fabricate, and test an active cooling, micro-channel heat sink device that can operate under atmospheric pressure...

This work studies the free convection heat transfer from a non-isothermal permeable cone with suction and temperature-dependent viscosity. A suitable coordinate transformation is used to transform the governing equations into nonsimilar boundary layer solutions, and the cubic spline collocation method is then employed to solve the obtained governing equations. The local Nusselt number is presen...

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The aim of this paper is to study the local Nusselt number of the symmetrical liquid-liquid jets emitting from a nozzle. Equations obtained from theoretical works are arranged in the form of a computerized model. The validity of this model was tested by the data from an experimental paper [1]. After few adjustments the model predicted the experimental data with a reasonable accuracy. Making...