کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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238595 | 465764 | 2009 | 7 صفحه PDF | دانلود رایگان |
Granular media subjected to vibration can approximate fluid behavior with sufficient vibration acceleration. Unlike gas fluidization, the transition from a static bed to a liquid-like state is poorly defined and has primarily studied previously in shallow or 2D granular beds. Three granular states are identified in this work: the static, the quasi-static, and the vibro-fluidized state. These states are characterized for a deep granular bed through quantitative measurements of the power or torque required to rotate a vane within the granular media. In this study, the vane is rotated while the bed is subjected to vibration at 10 Hz with acceleration in the range 0 ≤ Γ = ω2 xmax/g ≤ 4.0. We define a critical dimensionless vibration acceleration, Γc, based on a dramatic decrease in vane power and the absence of a dynamic zero-shear rate torque, as the transition to vibro-fluidization. Typical of granular materials, significant hysteresis is observed in measuring these bed state transitions. These measurements of “granular rheology” provide a quantitative framework for defining these transitions.
Vibro-fluidization of a deep granular bed at a critical dimentionless vibration acceleration, Гc, is confirmed by dramatic decreases in vane power at high vane speed and by the absence of a dynamic zero-shear rate torque. Three granular states are identified: static, quasi-static and vibro-fluidized.Figure optionsDownload as PowerPoint slide
Journal: Powder Technology - Volume 192, Issue 1, 15 May 2009, Pages 33–39