An improved EMMS model for turbulent flow in pipe and its solution--颗粒学报PARTICUOLOGY

Zhang, L., Huang, W. L., & Chen, J. (2023). An improved EMMS model for turbulent flow in pipe and its solution. Particuology, 76, 1-12. https://doi.org/10.1016/j.partic.2022.07.013

An improved EMMS model for turbulent flow in pipe and its solution

Lin Zhang ^*, Wen Lai Huang, Jianhua Chen

State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China

10.1016/j.partic.2022.07.013

Volume 76, May 2023, Pages 1-12

Received 23 June 2022, Revised 19 July 2022, Accepted 27 July 2022, Available online 16 August 2022, Version of Record 9 September 2022.

E-mail: zhanglin@ipe.ac.cn

Highlights

Abstract

Based on the existing energy-minimization multi-scale (EMMS) model for turbulent flow in pipe, an improved version is proposed, in which not only a new radial velocity distribution is introduced but also the quantification of total dissipation over the cross-section of pipe is improved for the dominant mechanism of fully turbulent flow in pipe. Then four dynamic equality constraints and some other constraints are constructed but there are five parameters involved, leading to one free variable left. Through the compromise in competition between dominant mechanisms for laminar and fully turbulent flow in pipe respectively, the above four constructed dynamic equality constraints can be closed. Finally, the cases for turbulent flow in pipe with low, moderate and high Reynolds number are simulated by the improved EMMS model. The numerical results show that the model can obtain reasonable results which agree well with the data computed by the direct numerical simulation and those obtained by experiment. This illustrates that the improved EMMS model for turbulent flow in pipe is reasonable and the compromise in competition between dominant mechanisms is indeed a universal governing principle hidden in complex systems. Especially, one more EMMS model for a complex system is offered, promoting the further development of mesoscience.

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