本研究是有關橢圓長寬比在二維乾燥顆粒混合物中分層現象效應影，顆粒混合物由單一橢圓顆粒(示蹤顆粒)與大量且相同的圓球顆粒(環境顆粒)所組成。數值模擬結果指出，隨著橢圓長寬比的增加，示蹤顆粒上升至混合物頂部的時間變短：並有著增強分離現象。這樣的效應和因顆粒大小導致分層現象的結果相比較，更可以明顯的觀察到。對於橢圓示蹤顆粒的上升運動，結果發現存在著五個物理機制有著許多的貢獻：
(1)拱效應的形成
(2)滲透機制作用
(3)示蹤顆粒的投影面
(4)示蹤顆粒的力矩效應
(5)近示蹤顆粒的環境顆粒之移動軌跡影響

The present study is concerned with the effects of the aspect ratio on the segregation phenomena in a binary dry granular mixture composed of a single elliptic particle ( trace particle ) and a large amount of identical spherical particles ( environmental particles ). Numerical simulations show that as the aspect ratio increases, the time span for the trace particle rising to the top of the mixture becomes shorter: an index for the enhanced segregation phenomena. Such an effect becomes more obvious when compared to the result from the size-induced segregation phenomena. It is found that there exist five physical mechanisms that many contribute to the rising motions of the elliptic trace particle:
(i) the formation of the arch effects ;
(ii) the permeation effects ;
(iii) the projection area of the trace particle ;
(iv) the tilding torque of the trace particle; and
(v) the moving trajectory of the environmental particles near the trace particle.

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