• 作者： Wang, Yeh
• 中文摘要： 本文係考慮具降服應力流體在不規則直管內之流動分析。塑性流體之流變模式為三維之賓漢模式,流動模擬則使用有限元素方法。根據模擬結果,塑性流體在直管內流動時,於管中央呈栓狀流動,而栓狀流動區之外形則與降服應力之大小有關,同時栓狀區之大小則由橫向之剪力所決定。再者,塑性流體在非圓直管內之角隅區產生停滯現象。有限元素法之模擬結果亦與圓管之解析解比較,兩者幾乎完全一致。
• 英文摘要： The flow of fluids with yield values through ducts of irregular shape is considered. Three-dimensional viscoplastic model of Bingham formulations are used. The flow simulation uses finite element computational procedures. The fluids investigated exhibit solid plug moving with constant velocity in the middle of the cross section. The shape of the mobile plug as well as the velocity field are determined. The shape of the plug depends on the yield stress of the fluid; and its magnitude is limited by transverse shearing. Numerical calculations also indicate the existence of stagnant regions around the corners in the square duct. Comparisons made with the analytical solutions of Bingham fluids in the circular duct are in good agreement.
• 中文關鍵字： 塑性流體; 變分原理; 規則化; 自由邊界; 賓漢數; 有限元素法
• 英文關鍵字： Viscoplastic Fluid; Variational Principle; Regularization; Free Boundary; Bingham Number; Finite Element Method