Natural convective heat transfer characteristics of Rayleigh-Benard convection of Al₂O₃-water nanofluids

Heterogeneous nanofluids: natural convection heat transfer enhancement

Convective heat transfer using different nanofluid types is investigated. The domain is differentially heated and nanofluids are treated as heterogeneous mixtures with weak solutal diffusivity and possible Soret separation. Owing to the pronounced Soret effect of these materials in combination with a considerable solutal expansion, the resulting solutal buoyancy forces could be significant and ...

Heat transport in turbulent rayleigh-Benard convection

We present measurements of the Nusselt number N as a function of the Rayleigh number R in cylindrical cells with aspect ratios 0. 5</=gamma identical withD/d</=12.8 ( D is the diameter and d is the height). We used acetone with a Prandtl number sigma = 4.0 for 10(5) less, similarR less, similar4x10(10). A fit of a power law N = N(0)R(gamma(eff)) over limited ranges of R yielded values of gamma(...

Lattice Boltzmann Simulation of Nanofluids Natural Convection Heat Transfer in Concentric Annulus (TECHNICAL NOTE)

Abstract   This study is applied Lattice Boltzmann Method to investigate the natural convection flow utilizing nanofluids in a concentric annulus. A numerical strategy presents for dealing with curved boundaries of second order accuracy for both velocity and temperature fields. The fluid between the cylinders is a water-based nanofluid containing different types of nanoparticles: copper (Cu), a...

Convective Heat Transfer Enhancement of CNT-Water Nanofluids in Plain Tube Fitted with Wire Coil Inserts

Unsteady Heating of Rayleigh-Benard Convection

The linear thermal instability of a horizontal fluid layer with time-periodic temperature distribution is studied with the help of the Floquet theory. The time-dependent part of the temperature has been expressed in Fourier series. Disturbances are assumed to be infinitesimal. Only even solutions are considered. Numerical results for the critical Rayleigh number are obtained at various Prandtl ...