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.

Perforated Helical Segments Chaotic Advection Darcy Friction Coefficient Shear Rate Lyapunov Exponent

Rahmani RK, Keith TG, Ayasoufi A, J. Fluids Eng., 128, 467 (2006)
Regner M, Ostergren K, Tragardh C, Ind. Eng. Chem. Res., 47(9), 3030 (2008)
Regner M, Ostergren K, Tragardh C, Chem. Eng. Sci., 61(18), 6133 (2006)
Thakur RK, Vial C, Nigam KDP, Nauman EB, Djelveh G, Chem. Eng. Res. Des., 81(7), 787 (2003)
Ghanem A, Lemenand T, Della Valle D, Peerhossaini H, Chem. Eng. Res. Des., 92(2), 205 (2014)
Zidouni F, Krepper E, Rzehak R, Rabha S, Schubert M, Hampel U, Chem. Eng. Sci., 137, 476 (2015)
Hobbs DM, Muzzio FJ, Chem. Eng. J., 67, 153 (1997)
Hobbs DM, Muzzio FJ, AIChE J., 43(12), 3121 (1997)
Hobbs DM, Muzzio FJ, Chem. Eng. Sci., 53(18), 3199 (1998)
Hobbs DM, Muzzio FJ, Chem. Eng. Sci., 70, 93 (1998)
Fourcade E, Wadley R, Hoefsloot HCJ, Green A, Iedema PD, Chem. Eng. Sci., 56(23), 6729 (2001)
Rahmani RK, Keith TG, Ayasoufi A, J. Fluids Eng., 127, 467 (2005)
Lisboa PF, Fernandes J, Simoes PC, Mota JPB, Saatdjian E, J. Supercrit. Fluids, 55(1), 107 (2010)
Saatdjian E, Rodrigo AJS, Mota JPB, Chem. Eng. J., 187, 289 (2012)
Kumar V, Shirke V, Nigam KDP, Chem. Eng. J., 139(2), 284 (2008)
Jaworski Z, Pianko-Oprych P, Marchisio DL, Nienow AW, Chem. Eng. Res. Des., 85(A5), 753 (2007)
Tajima H, Yamasaki A, Kiyono F, Teng H, AIChE J., 50(4), 871 (2004)
Tajima H, Yamasaki A, Kiyono F, Energy Fuels, 19(6), 2364 (2005)
Tajima H, Yamasaki A, Kiyono F, Teng H, AIChE J., 52(8), 2991 (2006)
Tajima H, Yoshida Y, Abiko S, Yamagiwa K, Chem. Eng. J., 156(2), 479 (2010)
Ujhidy A, Nemeth J, Szepvolgyi J, Chem. Eng. Process., 42(1), 1 (2003)
Lang E, Drtina P, Streiff F, Fleischli M, Int. J. Heat Mass Transf., 38(12), 2239 (1995)
Mickaily-Huber ES, Bertrand F, Tanguy P, Meyer T, Renken A, Rys FS, Wehrli M, Chem. Eng. J. Biochem. Eng. J., 63, 117 (1996)
Zalc JM, Szalai ES, Muzzio FJ, Jaffer S, AIChE J., 48(3), 427 (2002)
Hirech K, Arhaliass A, Legrand J, Ind. Eng. Chem. Res., 42(7), 1478 (2003)
Rabha S, Schubert M, Grugel F, Banowski M, Hampel U, Chem. Eng. J., 262, 527 (2015)
Meng HB, Wang F, Yu YF, Song MY, Wu JH, Ind. Eng. Chem. Res., 53(10), 4084 (2014)
Meng HB, Song MY, Yu YF, Wang F, Wu JH, Can. J. Chem. Eng., 93(10), 1849 (2015)
Yu YF, Wang HY, Song MY, Meng HB, Wang ZY, Wu JH, Appl. Therm. Eng., 94, 282 (2016)
Lei YG, Zhao CH, Song CF, Chem. Eng. Technol., 35(12), 2133 (2012)
Meng HB, Zhu GX, Yu YF, Wang ZY, Wu JH, Int. J. Heat Mass Transf., 99, 647 (2016)
Curran SJ, Hayes RE, Afacan A, Williams MC, Tanguy PA, Ind. Eng. Chem. Res., 39(1), 195 (2000)
Bakker A, Gates LE, Chem. Eng. Prog., 91(12), 25 (1995)
Rauline D, Tanguy PA, Le Blevec JM, Bousquet J, Can. J. Chem. Eng., 76(3), 527 (1998)
Heywood NI, Viney LJ, Stewart IW, Fluid Mixing II, 147 (1984)
ANSYS Inc., ANSYS ICEM CFD Help Manual. ANSYS Inc. Southpointe 2600 ANSYS Drive Canonsburg, PA, U.S.A. (2015).
Cengel Y, Ghajar A, Heat and Mass Transfer: Fundamentals and Applications, McGraw-Hill Science/Engineering/Math, USA (2014).
Grace HP, Chem. Eng. Commun., 14, 225 (1982)
Heniche M, Tanguy PA, Reeder MF, Fasano JB, AIChE J., 51(1), 44 (2005)
ANSYS Inc., ANSYS Fluent User’s Guide. ANSYS Inc. Southpointe 2600 ANSYS Drive Canonsburg, PA, U.S.A. (2015).
Ottino JM, The kinematics of mixing: stretching, chaos, and transport, Cambridge University Press, Cambridge (1989).
Rauline D, Le Blevec JM, Bousquet J, Tanguy PA, Chem. Eng. Res. Des., 78(3), 389 (2000)
Liu M, Peskin RL, Muzzio FJ, Leong CW, AIChE J., 40(8), 1273 (1994)
Liu M, Muzzio FJ, Peskin RL, Chaos Solitons & Fractals, 4, 2145 (1994)