間隙流體含量與黏滯性對滑道顆粒流崩塌行為之影響

我們建構一個包含傾斜滑道與儲存槽的實驗裝置，去探討不同體積的間隙流體與傾斜角的儲存槽內顆粒崩塌行為。藉由高速攝影機搭配霍夫轉換及粒子追蹤測速法觀測相同重力位能下之固液混合體暫態行為，可以發現非沉浸、部分沉浸與完全沉浸情況下，顆粒混合體的體積分率、速度、底床滑動速度及應變率大小及分布情況有所不同。共存液體對於統御流場顆粒行為有著較大的影響，從沉浸混合體比乾混合體較適用於顆粒流的1-D Savage-Hutter model可以得知。

關鍵字

儲存槽；顆粒崩塌行為；間隙流體體積；霍夫轉換；粒子追蹤測速法

並列摘要

A laboratory-scale facility composed of an inclined flume and the reservoir is constructed to investigate the moving avalanche of granular behavior with respect to various inclinations and interstitial liquid volume. The unsteady bulk motion of the granular mixtures prepared with matched same potential energy is obtained by employing the high-speed camera with the methods of Circular Hough Transform (CHT) and particle tracking velocimetry (PTV). We find that the bulk-averaged velocity, basal slip velocity and strain-rate profiles of the mixtures are different under non-immersed, partially-immersed and fully-immersed situations. Coexisting liquid has a strong effect on unifying the bulk motion across the flow depth, which indicates that the Savage-Hutter model developed for surface granular flow may be more feasible for capturing the avalanche of immersed mixtures than dry bulk.

並列關鍵字

reservoir ； avalanche of granular behavior ； interstitial liquid volume ； CHT ； PTV

參考文獻

Armanini, A., Capart, H., Fraccarollo, L., and Larcher, M. “Rheologicalstratification in experimental free-surface flows of granular-liquid mixtures,” J.Fluid Mech. 532, 269-319 (2005)

Ahn H., Brennen C.E. and Sabersky R.H., “Analysis of the Fully Developed Chute Flow of Granular Materials,” Applied Mechanics. 59, 109-119 (1992)

Bagnold, R. A. “Experiments on a gravity-free dispersion of large solid spheres in a Newtonian fluid under shear,” Proc. R. Soc. Lond. A 225, 49-63 (1954)

Balmforth, N. J. and Kerswell, R. R. “Granular collapses in two dimensions,” J. Fluid Mech. 38, 399-428 (2005)

Bocquet L., Charlaix, É., and Restagno, F. “Physics of humid granular media,” C.R. Physique. 3 207–215 (2002)

國際替代計量

間隙流體含量與黏滯性對滑道顆粒流崩塌行為之影響

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