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...

an experimental and theoretical energy and exergy analysis was conducted for a cylindrical cavity receiver employed in a parabolic dish collector. based on simultaneous energy and exergy analysis, the receiver average wall temperature and overall heat transfer coefficient were determined. a simplified nusselt number for heat transfer fluid (htf) through the receiver as a function of reynolds an...

In the present study, a finite volume method is employed to model the advection-diffusion phenomenon during a pure substance melting process. The exercise is limited to a benchmark problem consisting of the 2D melting from a vertical wall of a PCM driven by natural convection in the melt. Numerical results, mainly the temporal evolution of average Nusselt number at the hot wall and the average ...

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 ...

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...

In this work transient mixed convection in a porous medium in a horizontal channel with a open cavity below is studied numerically. The cavity presents a heated wall at uniform heat flux and the other walls of the cavity and the channel are assumed adiabatic. Air flows through the horizontal channel. The heated wall of the cavity experiences a uniform heat flux in such a way that the forced flo...

Steady natural convection flow in an inclined square cavity filled with a porous medium has been investigated. It is assumed that the cavity is heated on one wall and cooled from an adjacent wall, while the other two walls are adiabatic. The governing dimensionless partial differential equations have been solved numerically for the stream function, isotherms, and the local and average Nusselt n...

We report results from Direct Numerical Simulation (DNS) of rotating Rayleigh-Bénard convection, regarding the scaling of heat transfer with the Rayleigh number for rotating systems at a fixed rate of rotation. The Prandtl number, Pr = 6.4, is kept constant. We perform simulations, using a spectral element method, for Rayleigh numbers Ra from 10 to 10, and Rossby numbers Ro from 0.09 to∞. We fi...

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