City Research Online

Experimental and numerical investigation of tip leakage flows in a roots blower

Sun, S., Singh, G., Kovacevic, A. ORCID: 0000-0002-8732-2242 and Bruecker, C. ORCID: 0000-0001-5834-3020 (2020). Experimental and numerical investigation of tip leakage flows in a roots blower. Designs, 4(1), 3.. doi: 10.3390/designs4010003

Abstract

Computational fluid dynamics (CFD) can help in understanding the nature of leakage flow phenomena inside the rotary positive displacement machines (PDMs). However, due to the lack of experimental results, the analysis of leakage flows in rotary PDMs by CFD has not yet been fully validated. Particle image velocimetry (PIV) tests with a microscopic lens and phase-lock were conducted to obtain the velocity field around the tip gap in an optical Roots blower. The three-dimensional unsteady CFD model of the Roots blower with the dynamic grids generated by Screw Compressor Rotor Grid Generation (SCORG) was established to predict the gap flow under the same operating conditions. The images obtained by the PIV tests were analyzed and some factors which compromise the quality of test results in the gap flow were identified, such as reflections and transparency of the window. The flow fields obtained by CFD have the same flow pattern and velocity magnitude as the experimental results in the majority of observed regions but overestimate the leakage flow velocity. The CFD results show a vortex induced by the leakage flow in the downstream region of the gap. The flow losses in the tip gap mainly happen at the entrance upstream of the gap. Finally, some suggestions for future work are discussed.

Publication Type: Article
Additional Information: This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Publisher Keywords: positive displacement machines; roots blower; micro PIV; tip leakage flows; CFD
Subjects: T Technology > TL Motor vehicles. Aeronautics. Astronautics
Departments: School of Mathematics, Computer Science & Engineering > Engineering > Mechanical Engineering & Aeronautics
Date Deposited: 20 Nov 2020 14:37
URI: https://openaccess.city.ac.uk/id/eprint/25285
[img]
Preview
Text - Published Version
Available under License Creative Commons: Attribution International Public License 4.0.

Download (2MB) | Preview

Export

Downloads

Downloads per month over past year

View more statistics

Actions (login required)

Admin Login Admin Login