Unsteady helical flows of a generalized Oldroyd-B fluid

✍ Scribed by Dengke Tong; Xianmin Zhang; Xinhong Zhang

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 288 KB
• Volume: 156
• Category: Article
• ISSN: 0377-0257
• DOI: 10.1016/j.jnnfm.2008.07.004

✦ Synopsis

Helical flows for Oldroyd-B fluid are studied in concentric cylinders and a circular cylinder. The fractional calculus approach in the constitutive relationship model Oldroyd-B fluid is introduced and a generalized Jeffreys model with the fractional calculus has been built. Exact solutions of some unsteady helical flows of Oldroyd-B fluid in an annular pipe are obtained by using Hankel transform and Laplace transform for fractional calculus. For ˛= ˇ= 1, 1 = 0, 2 = 0 or 1 = 2 = 0 they reduce to the similar solutions for a Maxwell fluid, a second grade or Newtonian fluid, respectively. Numerical results for helical flow in pipe are presented.