Dependence of Granular Heat Transfer Performance on Vibration Characteristics in Vibrationally Fluidized BedsBeds

Heat transfer in granular materials has many industrial applications, including food produc-tion, solar energy harvesting and nuclear engineering. The present research studies the effect of vibration characteristics on granular heat transfer in a vibrationally fluidized bed of parti-cles using a three-dimensional discrete element method. The bed is heated by transferring a constant heat flux from its bottom wall. It was found that vibrations generally had two influ-ences: first, particles reached a higher average temperature, and second, they attained a more uniform temperature distribution. The particles average temperature generally increased by increasing vibration amplitude. However, the best temperature uniformity occurred in an op-timal set of amplitudes and frequencies. As vibration intensified, heating cycles were gener-ated, causing the particles temperature increases faster since the heat is conducted to the par-ticles directly from the heated bottom wall. The generation of heating cycles had a fundamen-tal role on controlling granular heat transfer in vibrating beds.

Keywords:

vibration , heat transfer , discrete element modeling , fluidization.