Skip to main content

Research Repository

Advanced Search

Computational investigation of flows and pressure fields associated with spur gear meshing

Baydu, C. Al; Simmons, Kathy; Morvan, Herve


C. Al Baydu

Professor of Mechanical and Aerospace Engineering

Herve Morvan


The efficiency of power transmission systems is increasingly targeted with a view to reducing parasitic losses and improving specific fuel consumption (SFC). One of the effects associated with such parasitic losses is the successive compression and expansion of fluid within the cavities between teeth of a meshing gear pair as they rotate. This process is cyclic and there are multiple cavities compressed and expanded at the same time.

During the meshing process the volume of the cavity between the teeth suddenly contracts and as a result pressure rises. The fluid is therefore expelled primarily in the axial direction (for spur gears) since this area is considerably larger compared to the backlash area. Once the cavity starts to expand fluid is drawn into the cavity between the teeth by the negative pressure. Besides the air flow in the gear box, the meshing point is of particular interest to the oil flow, since oil is typically injected at or upstream of the meshing point. Good understanding of such flows can be used to balance lubrication needs with the need to minimise the required oil volumes and parasitic losses.

This paper proposes the use of Computational Fluid Dynamics (CFD) as a means to investigate the phenomenon. A simplified two-dimensional CFD approach has been developed to study flows and pressure fields associated with spur gear meshing. The influence of the rotational speed has been investigated. Good validation is shown for the transient pressure variation within the tooth space. The limitations and potential applications of the modelling strategy are then discussed.


Baydu, C. A., Simmons, K., & Morvan, H. (2014). Computational investigation of flows and pressure fields associated with spur gear meshing. In Volume 5C: Heat Transfer.

Conference Name ASME Turbo Expo 2014
End Date Jun 20, 2014
Acceptance Date Jun 1, 2014
Publication Date Jun 16, 2014
Deposit Date Jul 27, 2016
Peer Reviewed Peer Reviewed
Book Title Volume 5C: Heat Transfer
Keywords Pressure, Flow (Dynamics), Spur gears
Public URL
Publisher URL
Additional Information From: ASME Turbo Expo 2014: Turbine Technical Conference and Exposition Volume 5C: Heat Transfer Düsseldorf, Germany, June 16–20, 2014 ISBN: 978-0-7918-4573-8 Copyright © 2014 by Rolls-Royce plc