Slip and turbulence phenomena in journal bearings with application to implantable rotary blood pumps

• Published in: Tribology international 2016-12, Vol.104, p.157-165
• Main Authors: Paul, Gordon, Rezaienia, Amin, Shen, Xiang, Avital, Eldad, Korakianitis, Theodosios
• Format: Article
• Language: English
• ISSN: 0301-679X; 1879-2464
• DOI: 10.1016/j.triboint.2016.08.032

This paper describes an investigation into journal bearings with geometries and working fluid similar to centrifugal blood pumps. The aim is to describe the phenomena that cause these journal bearings to deviate from classical predictions. Experimental, analytical and numerical methods are used to investigate the behaviour of a range of bearings with geometries and working fluid similar to blood pumps. It was found that the clearance had a significant effect on the force-eccentricity characteristic of the bearing, with smallest and largest clearances deviating from classical predictions. Experimentally measured pressure distributions show that slip occurs when the clearance is small and that turbulence occurs with the largest clearances. The effects of these phenomena on lubricant pressure and blood compatibility are discussed. •Assuming laminar flow and a no-slip boundary condition causes inaccurate prediction of blood pump journal bearings.•Experiments show that slip and turbulence can occur in these journal bearings, causing deviation from the classical model.•Measurements of the force, load angle and pressure distribution allow insight into the effects of slip and turbulence.