Comparative Study of RANS and LES Simulation Methods for Analysis of Turbulence in a Tubular Stirred Reactor

Abstract:

Selecting a right simulation method is important for accurately predicting flow field in stirred reactor. The Reynolds-Averaged Navier-Stokes (RANS) approach with standard model and large eddy simulations (LES) method were both used to analyze the turbulent flow field in a tubular stirred reactor for leaching. Calculations were performed to study the effects of agitator speed and flux on the turbulent flow field. The velocity at different axial sections gained by the two methods was compared. Results showed that the eddy current, especially in the back of impellor, predicted by LES was better than that by standard model. At the same time，the average relative error of the mean residence time and the mixing time of the former reduced 5% and 13% respectively than that of the latter.

• Periodical: Advanced Materials Research (Volume 499)
• Pages: 218-222
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.499.218
• Online since: April 2012
• Authors: Qiu Yue Zhao, Ting An Zhang, Yan Liu, Xiao Chang Cao, Shu Chan Wang, Hong Liang Zhao
• Keywords: Flow Field, Mean Residence Time, Mixing Time, Numerical Simulation

References

[1] Xin Gu. Numerical Simulation of Shell-and-tube Heat Exchanger and Research on Sideling-flow Heat Exchanger. [D]. ZhengZhou city: ZhengZhou univercity，2006, 19-22.

[2] Yi Miao, JiaZhen Pan, Jian Min, et al. Large Eddy Simulation of Mixing Process in Stirred Tank with Rushton Turbine [J], Journal of East China University of Science and Technology(Natural Science Edition, 2006，32（5）：623-628.

[3] M. Tyagia. Simulation of laminar and turbulent impeller stirred tanks using immersed boundary method and large eddy simulation technique in multi-block curvilinear geometries [J], Chemical Engineering Science, 2007, 62: 1351-1363.

DOI: 10.1016/j.ces.2006.11.017

[4] J. Pan, E. Loth. Reynolds-averaged Navier-Stokes simulations of airfoils and wins with ice shapes[J], Journal of Aircraft, 2004, 41(4): 879-891.

DOI: 10.2514/1.587

[5] V. Michelassi, J. G. Wissink, W. Rodi. Direct numerical simulation, large eddy simulation and unsteady Reynolds-averaged Navier-Stokes simulations of periodic unsteady flow in a low-pressure turbine cascade: A comparison [J], Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 2003, 217(4): 403-412.

DOI: 10.1243/095765003322315469

[6] Ting'an Zhang, Qiuyue Zhao, Zhihe Dou, et al. internal loop multi-tubular digestion reactor [P]. ZL 200510047338. 3.

[7] Qiuyue Zhao. Design and physical and numerical simulation on flow characteristic of multi stirred tubular reactor [D]. ShenYang city: Northeastern University. 2008, 33-51.

[8] Luo J V, Gosman A D, Issa R I, et al. Fitzgerald M K. Full flow field computation of mixing in baffled stirred reactors [J]. Trans IChemE 1993, 71A: 342-344.

[9] Luo J V, Issa R I , Gosman A D. Prediction of impeller induced flows in mixing vessels using multiple frames of reference[J]. IChemE Symp Ser 163, 1994, 549-556.

[10] Chengyao Wang, Zhenghua Wang, Xiaohui Yang. Computational fluid dynamics and parallel algorithm [M]. Changsha city, Press of National University of Defense Technology, China, (2000).

[11] Guozhong Zhou; Yingcen Wang and Litian SHI. CFD study of mixing process in stirred tank [J]. Journal of Chemical Industry and Engineering(China), 2003, (54)7, 886-890.