Related Experiment Video
Updated: Jun 8, 2026

A Modeling and Simulation Method for Preliminary Design of an Electro-Variable Displacement Pump
Published on: June 1, 2022
Investigation of the influence of volute design on journal bearing bias force using computational fluid dynamics
Roland Graefe1, Daniel Timms, Fiete Böhning
1Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany. graefe@hia.rwth-aachen.de
Abstract:
Hydrodynamic fluid film bearings represent an optimal possibility for rotary blood pump (RBP) miniaturization and wear-free operation. Size is a key parameter in the development of ventricular assist devices (VADs) as smaller patients and the pediatric population become eligible for the device. In order to maintain rotor suspension, radial journal bearings have been widely used in industrial applications as well as in some VADs. A main influence on the performance of such a bearing is the applied hydraulic bias force. This study combines numerical and analytical approaches to determine the bias force of different impeller-volute configurations and the resulting eccentricity for the hydraulic design point and also for off-design operation. Significant differences occur for different impeller-volute configurations, with the circular volute displaying the most beneficial properties for a stable impeller suspension. Moreover, an analytical prediction of eccentricity was found to be incorrect for the relatively small forces that occur in RBPs.
Related Concept Videos
Journal Bearings
To better understand the concept of journal bearings, consider a rope winch with dry or...
Hydrostatic Pressure Force on a Curved Surface
Fluid Pressure over Curved Plate of Constant Width
Design Example: Deciding Thickness of Lubricating Fluid in a Shaft
To calculate the required thickness of the lubricant layer, the tangential velocity at the shaft's surface must first be determined. This velocity is calculated by converting the rotational speed to angular velocity...
Bearings: Problem Solving
Design of Transmission Shafts - Stress Analysis

