Numerical simulation of fluid dynamics in the stirred tank by the SSG Reynolds Stress Model
Numerical simulation of fluid dynamics in the stirred tank by the SSG Reynolds Stress Model
Nana QI1,2, Hui WANG1,3, Kai ZHANG1,4(), Hu ZHANG2()
1. State Key Lab of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China; 2. School of Chemical Engineering, University of Adelaide, Adelaide SA 5005, Australia; 3. Beijing Aerospace WanYuan Coal Chemical Engineering Technology CO., Ltd, Beijing 100176, China; 4. National Engineering Lab for Biomass Power Generation Equipment, North China Electric Power University, Beijing 102206, China
The Speziale, Sarkar and Gatski Reynolds Stress Model (SSG RSM) is utilized to simulate the fluid dynamics in a full baffled stirred tank with a Rushton turbine impeller. Four levels of grid resolutions are chosen to determine an optimised number of grids for further simulations. CFD model data in terms of the flow field, trailing vortex, and the power number are compared with published experimental results. The comparison shows that the global fluid dynamics throughout the stirred tank and the local characteristics of trailing vortices near the blade tips can be captured by the SSG RSM. The predicted mean velocity components in axial, radial and tangential direction are also in good agreement with experiment data. The power number predicted is quite close to the designed value, which demonstrates that this model can accurately calculate the power number in the stirred tank. Therefore, the simulation by using a combination of SSG RSM and MRF impeller rotational model can accurately model turbulent fluid flow in the stirred tank, and it offers an alternative method for design and optimisation of stirred tanks.
. Numerical simulation of fluid dynamics in the stirred tank by the SSG Reynolds Stress Model[J]. Frontiers of Chemical Engineering in China, 2010, 4(4): 506-514.
Nana QI, Hui WANG, Kai ZHANG, Hu ZHANG. Numerical simulation of fluid dynamics in the stirred tank by the SSG Reynolds Stress Model. Front Chem Eng Chin, 2010, 4(4): 506-514.
Buwa V, Dewan A, Nassar A F, Durst F. Fluid dynamics and mixing of single-phase flow in a stirred vessel with a grid disc impeller: experimental and numerical investigations. Chemical Engineering Science , 2006, 61(9): 2815–2822 doi: 10.1016/j.ces.2005.10.066
2
Montante G, Lee K C, Brucato A, Yianneskis M. Numerical simulations of the dependency of flow pattern on impeller clearance in stirred vessels. Chemical Engineering Science , 2001, 56(12): 3751–3770 doi: 10.1016/S0009-2509(01)00089-6
3
Khopkar A R, Mavros P, Ranade V V, Bertrand J. Simulation of flow generated by an axial-flow impeller: batch and continuous operation. Chemical Engineering Research & Design , 2004, 82(6 A6): 737–751
4
Li M, White G, Wilkinson D, Roberts K J. LDA measurements and CFD modeling of a stirred vessel with a retreat curve impeller. Industrial & Engineering Chemistry Research , 2004, 43(20): 6534–6547 doi: 10.1021/ie034222s
5
Panneerselvam R, Savithri S, Surender G D. CFD modeling of gas-liquid-solid mechanically agitated contactor. Chemical Engineering Research & Design , 2008, 86(12): 1331–1344 doi: 10.1016/j.cherd.2008.08.008
6
Murthy B N, Joshi J B. Assessment of standard k-epsilon, RSM and LES turbulence models in a baffled stirred vessel agitated by various impeller designs. Chemical Engineering Science , 2008, 63(22): 5468–5495 doi: 10.1016/j.ces.2008.06.019
7
Deglon D A, Meyer C J. CFD modeling of stirred tanks: numerical considerations. Minerals Engineering , 2006, 19(10): 1059–1068 doi: 10.1016/j.mineng.2006.04.001
8
Han L C. Numerical simulation of fluid flow in stirred tank reactors using CFD method. Dissertation for the Master Degree . Xiangtan: Xiangtan University, 2005 (in Chinese)
9
Speziale C G, Sarkar S, Gatski T. Modeling the pressure strain of turbulence: an invariant dynamical systems approach. Journal of Fluid Mechanics , 1991, 227(-1): 245–272
10
Wu H, Patterson G K. Laser-Doppler measurements of turbulent flow parameters in a stirred mixer. Chemical Engineering Science , 1989, 44(10): 2207–2221 doi: 10.1016/0009-2509(89)85155-3
Rhie C M, Chow W L. Numerical study of the turbulent flow past an airfoil with trailing edge separation. AIAA Journal , 1983, 21(11): 1525–1532 doi: 10.2514/3.8284
13
Ranade V V, Joshi J B. Flow generated by a disc turbine. Part II: mathematical modelling and comparison with experimental data. Chemical Engineering Research & Design , 1990, 68A: 34–50
14
Zhang H, Lamping S R, Ayazi S P. Numerical simulation of mixing in a micro-well scale bioreactor by computational fluid dynamics. Chemical Research in Chinese Universities , 2002, 18(2): 113–116
15
Ranade V V, Dommeti S M S. Computational snapshot of flow fenerated by axial impellers in baffled stirred vessels. Chemical Engineering Research & Design , 1996, 74: 476–484
16
Brucato A, Ciofalo M, Grisafi F, Micale G. Numerical prediction of flow fields in baffled stirred vessels: a comparison of alternative modeling approaches. Chemical Engineering Science , 1998, 53(21): 3653–3684 doi: 10.1016/S0009-2509(98)00149-3
17
Luo J Y, Gosman A D, Issa R I, Middleton J C, Fitzgerald M K. Full flow field computation of mixing in baffled stirred vessel. Chemical Engineering Research & Design , 1993, 71: 342–344
18
Dong L, Johansen S T, Engh T A. Flow induced by an impeller in an unbaffled tank-II numerical modeling. Chemical Engineering Science , 1994, 49(20): 3511–3518 doi: 10.1016/0009-2509(94)00150-2
19
Koh P T L, Schwarz M P. CFD Modelling of bubble-particle attachments in a flotation cell. In: Proc. Centenary of Flotation Symposium, Brisbane , 2005, 201–207
20
Koh P T L, Schwarz M P, Zhu Y, Bourke P, Peaker R, Franzidis J P. Development of CFD models of mineral flotation cells. In: Proc. Third International Conference on CFD in the Minerals and Process Industries. Melbourne , 2003, 171–175
22
Escudié R, Bouyer D, Liné A. Characterization of trailing vortices generated by a Rushton turbine. AIChE Journal. American Institute of Chemical Engineers , 2004, 50(1): 75–86 doi: 10.1002/aic.10007
23
Zhu X Z, Miao Y, Xie Y J. Three-dimensional flow numerical simulation of double turbine impellers. Petro-Chem Equip , 2005, 34(4): 26–29 (in Chinese)
24
Chen Y C. Design of agitating equipment. Shanghai: Shanghai scientific & Technical Publishers, 1990 (in Chinese)
25
Kshatriya S S, Patwardhan A W, Eaglesham A. Experimental and CFD characterization of gas dispersing asymmetric parabolic blade impellers. Int J Chem Reactor Eng , 2007, 5(1): A1 doi: 10.2202/1542-6580.1381
