Flow of power-law fluids over a moving wedge surface with wall mass injection


Akçay M., Yükselen M. A.

Archive of Applied Mechanics, vol.81, no.1, pp.65-76, 2011 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 81 Issue: 1
  • Publication Date: 2011
  • Doi Number: 10.1007/s00419-009-0393-z
  • Journal Name: Archive of Applied Mechanics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.65-76
  • Keywords: Drag reduction, Injection, Moving wall, Non-Newtonian fluid, Power-law fluid, Wedge flow
  • Istanbul Gelisim University Affiliated: No

Abstract

The boundary layer problem of a power-law fluid flow with fluid injection on a wedge whose surface is moving with a constant velocity in the opposite direction to that of the uniform mainstream is analyzed. The free stream velocity, the injection velocity at the surface, moving velocity of the wedge surface, the wedge angle and the power law index of non-Newtonian fluid are assumed variables. The fourth order Runge-Kutta method modified by Gill is used to solve the non-dimensional boundary layer equations for non-Newtonian flow field. Without fluid injection, for every angle of wedge β, a limiting value for velocity ratio λ cr (velocity of the wedge surface/velocity of the uniform flow) is found for each power-law index n. The value of λ cr increases with the increasing wedge angle β. The value of wedge angle also restricts the physical characteristics of the fluid to be used. The effects of the different parameters on velocity profile and on skin friction are studied and the drag reduction is discussed. In case of C = 2.5 and velocity ratio λ = 0.2 for wedge angle β = 0.5 with the fluid with power law-index n = 0.5, 48.8% drag reduction is obtained. © 2009 Springer-Verlag.