Effects of a depletion layer on flow in a rotating channel

• Published in: Mechanics research communications Vol. 76; pp. 57 - 63
• Main Author: Ng, Chiu-On
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2016
• Subjects: Depletion layer; Fåhræus–Lindqvist effect; Rotating channel; Slip; Fåhræus–Lindqvist effect; Depletion layer; Rotating channel; Slip
• ISSN: 0093-6413; 1873-3972
• DOI: 10.1016/j.mechrescom.2016.07.006

•Poiseuille flow under the combined effect of system rotation and a depletion layer.•Complex Navier slip length.•Fåhræus–Lindqvist effect in a rotating channel. An analytical model is presented for pressure-driven two-fluid flow between two parallel flat plates rotating about an axis perpendicular to the plates. The aim is to determine the lubricating effects due to a near-wall low-viscosity depletion layer on the axial as well as transverse flows in a rotating channel. It is found that the primary and secondary flow fields may be affected differently by the system rotation, the thickness of the depletion layer, and the viscosity ratio. For a very thin depletion layer, the wall lubrication reduces to a Navier slip condition, where the slip length is found to be the same as the one for a non-rotating channel at the leading order, while the higher-order slip length is a function of a complex rotation parameter. The Fåhræus–Lindqvist effect in a rotating environment is also examined.