Laminar flow and chaotic advection mixing performance in a static mixer with perforated helical segments

다국어 초록 (Multilingual Abstract)

The laminar flow and chaotic mixing characteristics of a high-viscosity fluid in static mixers with staggered perforated helical segments were numerically investigated in the range of Re=0.1-150. The numerical results of pressure drop of Kenics static mixer have a good agreement with the reported data from the literature. The effects of aspect ratio Ar and Reynolds number on the mixing performance of Modified Kenics Static Mixers (MKSM) were evaluated by Darcy friction coefficient, shear rate, stretching rate, and Lyapunov exponent, respectively. The product of f×Re for MKSM linearly increased with the increase of Re, but it was constant under Re<10. The values of shear rate in the first perforated hole of mixing elements gradually became much larger by 1.10%-11.78% than those in the second perforated hole with the increasing Re. With the increase of dimensionless axial mixing length, the stretching rate increased linearly and the sensitivity for initial condition gradually weakened. A larger Ar is beneficial for micro-mixing in creeping flow. The average Lyapunov exponent linearly increases with the increase of Re. The profiles of Lyapunov exponent at different dimensionless perforated diameter (d/W) and perforated spacing (s/W) indicate that the chaotic mixing in MKSM is much more sensitive to d/W than s/W. A dimensionless parameter η taking into account the mixing degree and pressure drop was employed to evaluate the mixing efficiency. The optimization of perforated helical segments with the highest mixing efficiency at Re=100 was d/W=0.55 and s/W=1.2.

참고문헌 (Reference)

1 R. K. Rahmani, 128 : 467-, 2006

2 M. Liu, 4 : 2145-, 1994

3 M. Regner, 61 : 6133-, 2006

4 R. K. Thakur, 81 : 787-, 2003

5 A. Ghanem, 92 : 205-, 2014

6 F. Zidouni, 137 : 476-, 2015

7 D. M. Hobbs, 67 : 153-, 1997

8 D. M. Hobbs, 43 : 3121-, 1997

9 D. M. Hobbs, 53 : 3199-, 1998

10 D. M. Hobbs, 70 : 93-, 1998

11 E. Fourcade, 56 : 6729-, 2001

12 R. K. Rahmani, 127 : 467-, 2005

13 P. F. Lisboa, 55 : 107-, 2010

14 E. Saatdjian, 187 : 289-, 2012

15 V. Kumar, 139 : 284-, 2008

16 H. Tajima, 52 : 2991-, 2006

17 Z. Jaworski, 85 : 753-, 2007

18 H. Tajima, 50 : 871-, 2004

19 H. Tajima, 19 : 2364-, 2005

20 E. S. Mickaily-Huber, 63 : 117-, 1996

21 H. Tajima, 156 : 479-, 2010

22 A. Ujhidy, 42 : 1-, 2003

23 E. Lang, 38 : 2239-, 1995

24 J. M. Zalc, 48 : 427-, 2002

25 K. Hirech, 42 : 1478-, 2003

26 S. Rabha, 262 : 527-, 2015

27 H. B. Meng, 53 : 4084-, 2014

28 H. B. Meng, 93 : 1849-, 2015

29 Y. F. Yu, 94 : 282-, 2016

30 Y. G. Lei, 35 : 2133-, 2012

31 H. B. Meng, 99 : 647-, 2016

32 S. J. Curran, 39 : 195-, 2000

33 A. Bakker, 91 : 25-, 1995

34 D. Rauline, 76 : 527-, 1998

35 N. I. Heywood, 147 : 1984

36 M. Regner, 47 : 3030-, 2008

37 M. Liu, 40 : 1273-, 1994

38 D. Rauline, 78 : 389-, 2000

39 M. Heniche, 51 : 44-, 2005

40 H. P. Grace, 14 : 225-, 1982

41 J. M. Ottino, "The kinematics of mixing: stretching, chaos, and transport" Cambridge University Press 1989

42 Y. Cengel, "Heat and Mass Transfer: Fundamentals and Applications" McGraw-Hill Science/Engineering/Math 2014

43 ANSYS Inc., "ANSYS ICEM CFD Help Manual" ANSYS Inc 2015

44 ANSYS Inc., "ANSYS Fluent User’s Guide" ANSYS Inc 2015