本論文是以類二維的精密旋轉鼓為實驗設備，並以實驗的方式探討添加微量液體含量及旋轉鼓轉速快慢，對不同密度顆粒在旋轉鼓中分離機制的影響。運用高解析及高速攝影機搭配影像分析及粒子追蹤的方法，分析及量測分離強度、安息角(Angle of Repose)、速度場變化等影響分離機制的重要指標。實驗結果顯示添加微量液體含量的多寡與轉速的快慢，會使混合的現象呈現較佳，也代表此兩項參數對於密度分離機制有顯著的影響；隨著無因次液體含量增加，顆粒體間的液橋隨之增厚，平均架橋數也跟著增多，顆粒間彼此吸附力量增加，因此會形成較大的安息角，並抑制分離效應；而當轉速增加時，重顆粒平均流動速度變快，轉速的提升代表外界供給系統的能量變大，因此重顆粒能有較大的動能與較快的速度，也使得間隙液體對速度的影響慢慢變小。實驗結果亦發現最終分離強度會隨著安息角變大而產生線性遞減的關係且無關於轉速及微量液體含量；本研究也試著將過去尺寸效應的數據結果與本研究密度效應的結果相互比較，結果顯示安息角與最終分離強度仍是維持線性遞減的關係。

The density-induced granular segregation phenomenon of wet granular materials was experimentally studied in a quasi-2D rotating drum. The motions of the granular materials were recorded by a high-speed camera. Image processing technology and particle tracking method were employed to measure the segregation intensity, repose angle and the velocities of heavy particles. The effects of liquid content and rotation speed on segregation index, angle of repose, and velocity field in the rotating drum were investigated and discussed in this paper. The experimental results indicate that the liquid content and rotation speed have significant influences on density-induced granular segregation. The segregation intensity is mitigated with the increase of liquid content because of the stronger cohesive force between particles. It also shows that segregation intensity is reduced with the increasing of rotation speed. The segregation index is demonstrated to be decreased with the increase of the repose angle of wet granular materials, regardless of the addition of liquid content, liquid viscosity, rotation speed, density effect and size effect.

1. Ennis, B.J., Green, J., and Davies, R., “The legacy of neglect in the U.S.,” Chem. Eng. Prog., Vol. 90, pp. 32-43, 1994.
2. Shamlon, P.A., “Handling of Bulk Solids: Theory and Practice,” Butterworth, pp.19 3, 1998.
3. Campbell, C.S., “Rapid granular flows,” Annu. Rev. Flu
id Mech., Vol. 22, pp. 57-92, 1990.4.Jaeger, H.M., and Na
gel, S.R., “Physics of the Granular State,” Sci., Vol. 25
5, pp. 1523-1531, 1992.
5. Henein, H., Brimacomble, J.K., and Watkinson, A.P.,
“Experimental study of transverse 37 bed motion in rotary kilns,” Metallurgy Trans. B, Vol. 14, pp. 191-205, 1983.
6. Rajchenbach, J., “Flow in powders: from discrete avalanches to continuous regime,” Phys. Rev. Lett., Vol. 65, pp. 2221-2224, 1990.
7. Mellmann, J., “The transverse motion of solids in rotating cylinders-forms of motion and transition behavi
or,” Powder Technol., Vol 118, pp. 251-270, 2001.
8. Rosato, A., Strandburg, K.J., Prinz, F., and Swendsen, R.H., “Why the Brazil nuts are on top: size segregation of particulate matter by shaking,” Phys. Rev. Lett., Vol. 58, pp. 1038-1040, 1987.
9. Knight, J. B., Jaeger, H. M., and Nagel, S. R., “Vibra
tion-induced size separation in granular media: The conve
ction connection,” Phys. Rev. Lett., Vol. 92, 114301, 199
3.
10. Duran, J., Mazozi, T., Clement, E., and Rajchenbach, J., “Size segregation in a two-dimensional sandpile: Conv
ection and arching effects,” Phys. Rev. E, Vol. 50, pp. 5138–5141, 1994.
11. Dury, C. M., and Ristow, G. H., “Competition of mix
ing and segregation in rotating cylinders,” Phys. Fluid, Vol. 11, pp. 1387-1394, 1999.
12. Jain, N., Ottino, J. M., and Lueptow, R. M., “Regimes of segregation and mixing in combined size and density granular systems: an experimental study,” Granular Matter, Vol. 7, pp.69-81, 2005.
13. Pohlman, N. A., Severson, B. L., Ottino, J. M., and Lueptow, R. M., “Surface roughness effects in granular matter: Influence on angle of repose and the absence of segregation,” Phys. Rev. E, Vol. 73, 031304, 2006.
14. Ulrich, S., Schroter, M., and Swinney H. L.,“Influe
nce of friction on granular segregation,” Phys.Rev. E, V
ol. 76, 042301, 2007.
15. Dziugys, A., and Navakas, R., “The role of friction in mixing and segregation of granular material,” Granular Matter, Vol. 11, pp. 403-416, 2009.
16. Liao, C.C., Hsiau, S.S., Tsai, T. H., and Tai, C. H., “Segregation to mixing in wet granular matter under vibration,” Chem. Eng. Sci., Vol. 65, pp.1109-1119, 2010.
17. Ristow G.H., “Particle mass segregation in a two-dimensional rotating drum,” Eur. Phys. Lett., Vol.28, pp. 97-101, 1994.
18. Huerta, D. A., and Ruiz-Suarez, J. C., “Vibration-induced granular segregation: A phenomenon driven by three mechanisms,” Phys. Rev. Lett., Vol. 96, pp.219-226, 2004.
19. Yang, W. L., and Hsiau, S.S., “The effect of liquid viscosity on sheared granular flows,” Chem. Eng. Sci., Vol. 61, pp. 6085-6095, 2006.
20. Klein, M., Tsai, L. L., Rosen, M. S., Pavlin, T., Candela, D., and Walworth, R. L., “Interstitial gas and density segregation of vertically vibrated granular media,” Phys. Rev. E, Vol. 74, 010301, 2006.
21. Shi, Q. F., Sun, G., Hou, M., and Lu, K. Q., “Density-driven segregation in vertically binary granular mixture,” Phys. Rev. E, Vol. 75, 061302, 2007.
22. Sanfratello, L., and Fukushima, E., “Experimental studies of density segregation in the 3D rotating cylin
der and the absence of banding,” Granular Matter, Vol.11 pp. 73-78, 2009.
23. Sanchez1, I., Gutiérrez, G., Zuriguel, I. and Maza, D., “Sinking of light intruders in a shaken granular bed
,” Phys. Rev. E, Vol. 81, 062301, 2010.
24. Pereira, G.G., Pucilowski S., Liffman K., and Cleary P.W., “Streak patterns in binary granular media in a rotating drum,” Appl. Math. Model., Vol. 35, pp. 1638-1646, 2011.
25. Tripathi, A., and Khakhar, D. V., “Density difference
-driven segregation in a dense granular flow,” J. Fluid Mech. Vol.717, pp. 643-669, 2013.
26. Liao,C. C.,Hsiau,S.S., Nien,H. C., “Density-driven spontaneous streak segregation patterns in a thin rotat
ing drum, ”Phys. Rev. E., Vol. 89, pp. 062204: 1-7, 2014.
27. Albert, R., Albert, I., Hombaker, D., Schiffer, P., and Barabasi, A. L., “Maximum angle of stability in wet and dry spherical granular media,” Phys. Rev. E, Vol. 56, pp. 6271-6274, 1997.
28. Rennie, P. R., Chen, X. D., Hargreaves, C., and Mack
ereth, A. R.,“A study of the cohesion of dairy powders, ”J. Food. Eng. 39, 277-284.1999.
29. Fraysse, N., Thome, H., and Petit, L., “Humidity effe
cts on the stability of a sandpile,” Eur. Phys. J. B, Vol
.11, pp. 615-619, 1999.
30. Nase, S. T., Vargas, W. L., Abatan, A. A., and McCart
hy, J. J., “Discrete characterization tools for cohesive granular material,” Powder Technol., Vol. 116, pp. 214-223, 2001.
31. Jain, K., Shi, D. L., and McCarthy, J. J., “Discrete characterization of cohesion in gas-solid flows,” Powder Tech., Vol. 146, pp. 160-167, 2002.
32. Hsiau, S. S., and Yang, S. C., “Numerical simulation of self-diffusion and mixing in a vibrated granular bed with the cohesive effect on liquid bridges,” Chem. Eng. Sci., Vol. 58, pp. 339-351, 2003.
33. Li, H. M., and McCarthy, J. J., “Controlling cohesive particle mixing and segregation,” Phys. Rev. Lett., Vol. 90, pp. 18430: 1-4, 2003.
34. Kohonen, M. M., Geromichalos, D., Scheel, M., Schie
rb, C., and Herminghausb, S., “On capillary bridges in wet granular materials,” Phys. A, Vol. 339, pp. 7-15, 2004.
35. Li, H. M., and McCarthy J. J., “Phase diagrams for cohesive particle mixing and segregation,” Phys. Rev. E, Vol.71, pp. 021305: 1-8, 2005.
36. Liao, C. C., Hsiau, S. S., Tsai, T. H. and Tai, C. H., 2010, “Segregation to Mixing in Wet Granular Matter under Vibration,” Chem. Eng. Sci., Vol. 65, pp.1109-1116.
37. Pietsch, W., "Size enlargement by agglomeration,"Sa
lle, Sauerlander Eds, pp. 33-37, 1990.
38. Fisher, R. A., “On the capillary forces in an ideal soil,” J. Agric. Sci., Vol. 16, pp. 492-505, 1926.
39. Lian, G., Thornton, C., and Adams, M. J., “Discrete particle simulation of agglomerate impact coalescence,” Chem. Eng. Sci., Vol. 53, pp. 3381-3391, 1998.
40. Mikami, T., Kamiya, H., and Horio, M., “Numerical simulation of cohesive powder behavior in a fluidized bed,” Chem. Eng. Sci.., Vol. 53, pp. 1927-1940, 1998.
41. Adams, M. J., and Perchard, V., “The cohesive forces between partilces with interstitial liquid,” Inst. Chem. Engng Symp., Vol. 91, pp. 147-160, 1985.
42. Danckwerts, P. V., “The definition and measurement of some characteristic of mixtures,” Appl. Sci. Res., Vol. 3, pp. 279-296, 1952.
43. Chou, S.H., Liao, C.C., Hsiau, S.S., “An experimental study on the effect of liquid content and viscosity on particle segregation in a rotating drum,” Powder Technol., Vol 201, pp. 266-272,2010.
44. Hsiau, S. S., Liao, C. C., Tai, C. H., Wang, C. Y., “The dynamics of wet granular matter under a vertical vibration bed,” Granular Matt., Vol. 15, pp.437-446, 20
13.