Dual Role of Viscosity During Start-Up of a Maxwell Fluid in a Pipe

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2004,（1）
• 页码范围: 114-116
• 页数: 3页
• 语种: 英文

摘要

Based on the exact solution of start-up flow of Maxwell fluids in a long circular straight pipe, the effect of viscosity on the time of flow establishment is analysed. It is found that the viscosity of Maxwell fluids plays a dual role.A key parameter is the dimensionless relaxation time λ-. For 0 ＜λ-＜ 0.0432, the viscosity mainly plays the same role as in Newtonian fluids, and the time of flow establishment decreases with the increasing viscosity; for λ- ＞ 0.0432, the viscosity mainly plays a role of strengthening the oscillation, and the time of flow establishment increases with the incremental viscosity.