Application of Hybrid RANS/LES turbulence models in rotor-stator fluid machinery: A comparative study
International Journal of Numerical Methods for Heat & Fluid Flow
ISSN: 0961-5539
Article publication date: 4 December 2017
Abstract
Purpose
This paper aims to improve performance prediction and to acquire more detailed flow structures so as to analyze the turbulence in complex rotor-stator flow.
Design/methodology/approach
Hydraulic retarder as typical fluid machinery was numerically investigated by using hybrid Reynolds-averaged Navier–Stokes (RANS)/large eddy simulation (LES) models CIDDES Algebraic Wall-Modeled Large Eddy Simulation (LES) (WMLES) S-Ω and dynamic hybrid RANS/LES (DHRL). The prediction results were compared and analyzed with a RANS model shear stress transport (SST) k-omega which was a recommended choice in engineering.
Findings
The numerical results were verified by experiment and indicated that the predicted values for three hybrid turbulence models were more accurate. Then, the transient flow field was further analyzed visually in terms of turbulence statistics, Reynolds number, pressure-streamline, vortex structure and eddy viscosity ratio. The results indicated that HRL approaches could capture unsteady flow phenomena.
Practical implications
This study achieves both in performance prediction improvement and better flow mechanism understanding. The computational fluid dynamics (CFD) could be used instead of flow visualization to a certain extent. The improved CFD method, the fine computational grid and the reasonable simulation settings jointly enhance the application of CFD in the rotor-stator flow.
Originality/value
The improvement was quite encouraging compared with the reported literatures, contributing to the CFD playing a more important role in the flow machinery. DHRL provided the detailed explanation of flow transport between rotor and stator, which was not reported before. Through it, the flow mechanism can be better understood.
Keywords
Acknowledgements
This work was supported by the National Natural Science Foundation of China (Grant No. 51675219).
Citation
Liu, C., Bu, W., Xu, D., Lei, Y. and Li, X. (2017), "Application of Hybrid RANS/LES turbulence models in rotor-stator fluid machinery: A comparative study", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 27 No. 12, pp. 2717-2743. https://doi.org/10.1108/HFF-08-2016-0312
Publisher
:Emerald Publishing Limited
Copyright © 2017, Emerald Publishing Limited