Meccanica (2010) 45: 187–198 DOI 10.1007/s11012-009-9236-9 Oblique stagnation slip flow of a micropolar fluid Y.Y. Lok · I. Pop · D.B. Ingham Received: 11 September 2008 / Accepted: 1 July 2009 / Published online: 21 July 2009 © Springer Science+Business Media B.V. 2009 Abstract This paper considers the problem of steady two-dimensional boundary layer flow of a micropolar fluid near an oblique stagnation point on a fixed sur- face with Navier’s slip condition. It is shown that the governing nonlinear partial differential equations ad- mit similarity solutions. The resulting nonlinear ordi- nary differential equations are solved numerically us- ing the Keller box method for some values of the gov- erning parameters. It is found that the flow character- istics depend strongly on the micropolar and slip para- meters. Keywords Micropolar fluid · Boundary layer · Oblique stagnation point · Slip flow Y.Y. Lok Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, 76109 Durian Tunggal, Melaka, Malaysia I. Pop ( ) Faculty of Mathematics, University of Cluj, CP 253, 3400 Cluj, Romania e-mail: pop.ioan@yahoo.co.uk D.B. Ingham Centre for Computational Fluid Dynamics, University of Leeds, Leeds LS2 9JT, UK Nomenclature a Strength of the irrotational stagnation-point flow A Constant in (19) and (23) A t Slip constant b Strain rate of the uniform shear flow C 1 ,C 2 Constants of integration K Micropolar material parameter l Characteristic length n Ratio of the microrotation vector component and the fluid skin friction at the wall (or wall shear stress) N Component of the microrotation vector normal to x –y plane p Pressure U 0 Characteristic velocity u, v Velocity components along x - and y -axes x s Point of zero wall shear stress x,y Cartesian coordinates along the plate and normal to it, respectively Greek Symbols α Shear flow parameter γ Velocity slip factor κ Vortex viscosity μ Dynamic viscosity ρ Density υ Kinematic viscosity ψ Stream function τ Wall shear stress