Arun S. Mujumdar

TL;DR: In this article, the authors presented a comprehensive model consisting of continuity and heat and mass balances of three phases in an unsteady state, which revealed the flow patterns and temperature distributions of gas and liquid phases in mineral granule over time.

TL;DR: In this paper, a hot-wire sensor was placed in the near wake and autocorrelated the turbulence signal to measure the shedding frequencies of D-section cylinders with the flat face facing both upstream and downstream.

Abstract: A pulsating fluidized bed is operated with two sequential durations designated as an on-period with injecting fluidization gas and an off-period without it. The heat transfer coefficient between a vertically immersed heater and bed in a pulsating fluidized bed is measured under various pulse cycles and fluidized particles. The obtained results are compared with those in a normal fluidized bed with continuous fluidization air injection. The relationship between heat transfer coefficients and bubble characteristics, evaluated using a digital video camera, has also been investigated. For certain fluidized particles and operating pulse cycles, the fluidization of particles and the increment of heat transfer coefficients can be obtained under a mean air velocity based on a pulse cycle duration smaller than the minimum fluidization air velocity in a normal fluidized bed. Under the pulse cycles where a static bed through the whole bed is formed in the off-period duration, the improved heat transfer rate over that in a normal fluidized bed can be measured. This may be attributed to large bubble formation. As heat transfer in the pulsating fluidized bed is obstructed with increasing time to keep a static bed due to the excessive off-period duration, it is indicated that there is an optimum off-period duration based on the heat transfer rate. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(4): 307–319, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10038

TL;DR: In this article , a computational fluid dynamic (CFD) numerical framework is employed based on the particle dynamics approach of an Euler-Euler two-fluid model coupling interphase transfer mechanisms.