本研究探討在二維雙壁旋轉鼓中放入不同形狀顆粒所產生的分離現象。本實驗觀察相同體積、相同密度但不同縱橫比的橢圓球顆粒與球形顆粒在不同轉速下的混合及分離狀況。實驗發現，顆粒形狀與轉速的改變會導致不同的分離結果。這些發現不僅能為顆粒動力學提供更深入的理解，也能為工業應用提供新的設計參考。 本研究透過實驗的方法來探討形狀效應在二維雙壁旋轉鼓上所產生的分離行為。實驗中，選用了四種相同體積、相同密度但不同縱橫比的橢圓球顆粒與球形顆粒，並將兩相顆粒分別放入二維雙壁旋轉鼓中，在固定填充率下以不同轉速進行混合。隨後利用高速攝影機記錄不同時間點的分離型態，最後藉由影像處理與分析，以釐清其背後的物理機制。 在實驗中，我們觀察到當不同縱橫比之橢圓球與球形顆粒混合時，會產生不同的混合型態。透過實驗結果發現於低轉速下，橢圓球顆粒傾向聚集於內圈，而球形顆粒多分佈於外圈；隨轉速提高，該分佈趨勢反轉，呈現相反的徑向偏析行為。此現象推測與顆粒形狀改變其運動方式以及顆粒之間的相互作用有關。此外形狀差異對實驗結果具顯著影響。兩相顆粒的縱橫比差異越大時，顆粒間的相互作用力增強，從而改變了分離的強度。 關鍵字： 二維旋轉鼓；雙壁旋轉鼓；顆粒形狀；顆粒分離;This study investigates the segregation phenomena arising from the introduction of particles with different shapes into a two-dimensional double-walled rotating drum. The experiments examine the mixing and segregation behaviors of ellipsoidal particles with different aspect ratios and spherical particles， all of which share identical volume and density， under various rotational speeds. The findings reveal that changes in particle shape and drum rotation speed lead to distinct segregation patterns. These observations not only deepen our understanding of granular dynamics but also provide new insights that may guide industrial design and applications. An experimental approach was employed to analyze the shape-induced segregation behavior within the two-dimensional double-walled rotating drum. Four types of particles—ellipsoids with different aspect ratios and spheres—were selected， all equal in volume and density. The two particle species were placed separately into the drum and mixed under a fixed fill ratio and a range of rotational speeds. A high-speed camera was used to record the segregation patterns over time， and image processing techniques were applied to analyze the recorded data and elucidate the underlying physical mechanisms. The experiments show that mixtures of ellipsoids with different aspect ratios and spherical particles exhibit distinct mixing patterns. At low rotational speeds， ellipsoidal particles tend to accumulate near the inner region of the drum， while spherical particles are predominantly distributed toward the outer region. As the rotational speed increases， this radial distribution trend reverses， resulting in the opposite segregation behavior. This phenomenon is presumed to be associated with the shape-dependent particle motion and the interactions between particles. Furthermore， particle shape differences have a significant impact on the segregation behavior: larger disparities in aspect ratio between the two particle species intensify interparticle interactions， thereby altering the strength of segregation. Keywords:Two-dimensional rotating drum; Double-walled rotating drum; Particle shape; Granular segregation
