Skip to content
Licensed Unlicensed Requires Authentication Published by De Gruyter March 2, 2016

Numerical Simulation of Chaotic Mixing in Single Screw Extruders with Different Baffle Heights

  • B.-P. Xu , L. He , M.-G. Wang , S.-Z. Tan , H.-W. Yu and L.-S. Turng


A kind of discontinuous baffle, which had the same length as the non-baffle zone distance, was inserted in the unwound channel of a single screw extruder to enhance mixing in the screw channel. The periodic unit of the flow channel was modeled as a dynamic system of complex duct flow. The finite volume method was used to solve the three-dimensional flow of purely viscous non-Newtonian fluid. Fluid particle tracking was performed by a fourth-order Runge–Kutta scheme. The effect of the baffle height on the mixing kinematics was investigated numerically. Poincaré sections were applied to reveal the different patterns and sizes of the KAM tubes. Distributive mixing was then visualized by the evolution of passive tracers initially located at different positions. The variance index and residence time distribution (RTD) were used to evaluate the statistical results. Among the four test cases, the results showed that the case with the baffle height equal to the screw depth had the largest chaotic mixing region, but the shortest mean residence time and the narrowest broadening of RTD under the same pressure gradient.

*Correspondence address, Mail address: Lih-Sheng Turng, Polymer Engineering Center, University of Wisconsin–Madison, Madison, WI 53706, USA. E-mail:


Aref, H., “Stirring by Chaotic Advection”, J. Fluid Mech., 143, 121 (1984) 10.1017/S0022112084001233Search in Google Scholar

Aref, H., “The Development of Chaotic Advection”, Phys. Fluids, 14, 13151325 (2002) 10.1063/1.1458932Search in Google Scholar

Danckwerts, P. V., “The Definition and Measurement of Some Characteristics of Mixtures”, Appl. Sci. Res., A3, 279296 (1952)10.1007/BF03184936Search in Google Scholar

Gouillart, E., Thiffeault, J. L. and Fin, M. D., “Topological Mixing with Ghost Rods”, Phys. Rev. E: Stat. Phys. Plasmas Fluids Relat., 73, 03631118 (2006) 10.1103/PhysRevE.73.036311Search in Google Scholar

Hwang, W. R., Kang, K. W. and Kwon, T. H., “Dynamical Systems in Pin Mixers of Single Screw Extruders”, AIChE J., 50, 13721385 (2004) 10.1002/aic.10130Search in Google Scholar

Hwang, W. R., Kwon, T. H., “Chaotic Volumetric Transports in a Single Screw Extrusion Process”, Polym. Eng. Sci., 17, 112 (2003) 10.1002/pen.10065Search in Google Scholar

Hwang, W. R., Kwon, T. H., “Dynamical Modeling of Chaos Single Screw Extruder and its Three Dimensional Numerical Analysis”, Polym. Eng. Sci., 40, 702714 (2000) 10.1002/pen.11200Search in Google Scholar

Jana, S. C., Metcalfe, G. and Ottino, J. M., “Experimental and Computational Studies of Mixing in Complex Stokes Flows – The Vortex Mixing Flow and Multicellular Cavity Flows”, J. Fluid Mech., 269, 199246 (1994) 10.1017/S0022112094001539Search in Google Scholar

Jana, S. C., Tjahjadi, M. and Ottino, J. M., “Chaotic Mixing of Viscous Fluid by Periodic Changes in Geometry: Baffled Cavity Flow”, AIChE J., 40, 17691781 (1994) 10.1002/aic.690401102Search in Google Scholar

Kim, S. J., Kwon, T. H., “Enhancement of Mixing Performance of Single Screw Extrusion Processes via Chaotic Flows. I. Basic Concepts and Experimental Study”, Adv. Polym. Technol., 15, 4154 (1996a) 10.1002/(SICI)1098-2329(199621)15:1<41::AID-ADV4>3.0.CO;2-KSearch in Google Scholar

Kim, S. J., Kwon, T. H., “Enhancement of Mixing Performance of Single Screw Extrusion Processes via Chaotic Flows. 2. Numerical Study”, Adv. Polym. Technol., 15, 5569 (1996b) 10.1002/(SICI)1098-2329(199621)15:1<41::AID-ADV4>3.0.CO;2-KSearch in Google Scholar

Lee, T. H., Kwon, T. H.A New Representative Measure of Chaotic Mixing in a Chaos Single Screw Extruder”, Adv. Polym. Technol., 18, 5368 (1999), 10.1002/(SICI)1098-2329(199921)18:1<53::AID-ADV6>3.0.CO;2-ZSearch in Google Scholar

Meleshko, V. V., Dunaeva, T. A., “Chaotic Advection in Stokes Flow in Semicircle”, Regular and Chaotic Dynamics, 8, 305312 (2003) 10.1070/RD2003v008n03ABEH000246Search in Google Scholar

Ottino, J. M., Muzzio, F. J., Tjahjadi, M., Franjione, J. G., Jana, S. C. and Kusch, H. A., “Chaos, Symmetry, and Self-Similarity-Exploiting Order and Disorder in Mixing Processes”, Science, 257, 754760 (1992) 10.1126/science.257.5071.754Search in Google Scholar

Ottino, J. M., Wiggins, S., “Applied Physics – Designing Optimal Micromixers”, Science, 305, 85486 (2004) 10.1126/science.1099343Search in Google Scholar

Phelps, J. H., Tucker, C. L., “Lagrangian Particle Calculations of Distributive Mixing: Limitations and Applications”, Chem. Eng. Sci., 61, 68266836 (2006) 10.1016/j.ces.2006.07.008Search in Google Scholar

Sivasamy, J., Che, Z., Wong, T. N., Nguyen, N. T. and Yobas, L., “A Simple Method for Evaluating and Predicting Chaotic Advection in Microfluidic Slugs”, Chem. Eng. Sci., 65, 53825391 (2010) 10.1016/j.ces.2010.06.017Search in Google Scholar

Springham, J., Sturman, R., “Polynomial Decay of Correlations in Linked-Twist Maps”, Ergodic Theory and Dynamical Systems, 34, 17241746 (2014). 10.1017/etds.2013.8Search in Google Scholar

Vikhansky, A., “Enhancement of Laminar Mixing by Optimal Control Methods”, Chem. Eng. Sci., 57, 27192725 (2002) 10.1016/S0009-2509(02)00122-7Search in Google Scholar

Xu, B-.P., Lnn, Y.-J., Yu, H.-W. and Turng, L.-S., “Chaotic Mixing in a Single Screw Extruder with a Moving Internal Baffle”, Polym. Eng. Sci., 54, 198207 (2014) 10.1002/pen.23531Search in Google Scholar

Received: 2015-08-26
Accepted: 2015-10-20
Published Online: 2016-03-02
Published in Print: 2016-03-02

© 2016, Carl Hanser Verlag, Munich

Downloaded on 29.9.2023 from
Scroll to top button