3,736 research outputs found
Recommended from our members
Lattice Boltzmann simulation of magnetic field effects on nanofluid
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.In this paper, the magnetic field effects on natural convection heat transfer in an enclosure filled with nanofluid are numerically investigated by using lattice Boltzmann method. The fluid in the enclosure is a water-based nanofluid containing Al2O3 nanoparticles. A uniform external magnetic field with different angles was applied. A series of simulation cases were carried out for different governing parameters including Hartmann number, Rayleigh number, the nanoparticle volume fractions and magnetic field angles. The results show that the increasing Rayleigh number and nanoparticle volume fraction improve the heat transfer in the enclosure. However, the heat transfer has been suppressed when Hartmann number increases. The results also indicate there are critical values for the Raleigh number and also the magnetic field orientation, at which the impacts of the solid volume fraction and magnetic field effects are the most pronounced
Recommended from our members
Numerical simulation of microflow over superhydrophobic surfaces by lattice Boltmann method
This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.The superhydrophobicity of a microchannel is determined by not only the wettability of channel wall but also the surface topography. Recent experiments have found that superhrydrophobic surfaces can be achieved by pattering roughness on hydrophobic surfaces. In this paper, the dynamics of two-phase flow in microchannel with different wettability and topography is studied numerically by the lattice Boltzmann method (LBM). The mechanism of drag reduction resulted from the superhydrophobicity is investigated. In
particular, the effect of different rough surfaces on superhydrophobicity is analyzed. It is found that flow behaviours are strongly affected by the wall wettability and topography. The results show that the LBM has a good application prospect in the study of drag reduction in microchannels.The UK Royal Society-NSFC (China) International Joint Project (2009-2011), China NSFC under grant (50920105504), and China Scholarship Council (CSC)
Analysis on green technology system and LCA CO2 emission reduction of phase II construction project of JDXG
Research on the suitability improvement of the standard of green campus in China based on STARS
Local shell-to-shell energy transfer via nonlocal Interactions in fluid turbulence
In this paper we analytically compute the strength of nonlinear interactions
in a triad, and the energy exchanges between wavenumber shells in
incompressible fluid turbulence. The computation has been done using
first-order perturbative field theory. In three dimension, magnitude of triad
interactions is large for nonlocal triads, and small for local triads. However,
the shell-to-shell energy transfer rate is found to be local and forward. This
result is due to the fact that the nonlocal triads occupy much less Fourier
space volume than the local ones. The analytical results on three-dimensional
shell-to-shell energy transfer match with their numerical counterparts. In
two-dimensional turbulence, the energy transfer rates to the near-by shells are
forward, but to the distant shells are backward; the cumulative effect is an
inverse cascade of energy.Comment: 10 pages, Revtex
- …