Birmingham Environment for Academic Research - University of ...

More documents

Recommendations

Info

High shear rotor-stator mixersA rotor-stator mixer consists of a rotor closely surrounded by a stator with a small gap between therotor and stator, typically of the order of 0.1 mm. High speed jets emerge from stator openings asthe rotor rotates at a few thousand rpm. Rotor-stator mixers have been used extensively in industryto make products containing dispersed solid and/or liquid such as shampoo, body lotion, mayonnaise,lipstick, toothpaste, printing ink, etc. However, the interaction between the rotor and stator,the effect of rotor and stator geometries on the mixing performance and the scale-up procedure forrotor-stator mixers are still not well understood. CFD simulation (Computational Fluid Dynamics)was used to investigate the hydrodynamics in the rotor-stator mixer. The presence of a small gapbetween the rotor and the stator and high speed of the rotor make the simulation of rotor-statormixers a very challenging task. The rotor diameter is 2.82 mm and the gap between the rotor and stator is 0.175 mm. The CFDmodel uses full 3-D with more than one million computational cells. Due to periodic nature of rotor-stator interaction, a transient slidingmesh model with a time step of 0.0005 s was used to simulate rotor rotation making this simulation very time consuming. Theflow patterns in the stator holes are characterised by emerging jets in the proximity of the leading edge which induce circulation flowsbehind them. Jets emerging from disintegrating stators (wide holes) move in the same direction as the rotor, while those emergingfrom slotted and square hole stators (narrow holes) move against the rotor. Laser Doppler anemometry was also used to measuretime-averaged velocity profiles of emerging jets and good agreements with CFD predictions were obtained. In all investigated statorsthe high energy dissipation rates occur in the proximity of the leading and trailing edges due to stagnations on those regions. Statorswith narrow holes generate a more uniform energy dissipation rate in the holes than stators with wide holes, suggesting that they canproduce dispersion with narrow drop size distribution. Two papers have been published from this work. Currently, the CFD simulationis used to simulate larger scale rotor-stator mixers to investigate the effect of scale-up procedures, i.e. constant tip speed and con-Adi UtomoDepartment of Chemical EngineeringPage 24
ContributorsNamePeter WinnDr Eirini MavritsakiChristoph BoehmeDr Colin RowatPhil MurgatroydAndrea GabrieleAndrew CookDave SmithGehao WangJianhua OuEvgueni GoudzovskiJulia HofingerBen JonesAndrew LogsdailDongsheng HeKhamis EssaNahia GilDr Adi UtomoContact Detailsp.j.winn@bham.ac.uke.mavritsaki@bham.ac.ukcxb632@bham.ac.ukc.rowat@bham.ac.ukpsm703@bham.ac.ukgabriele.andrea@gmail.coma.j.cook@cmsoftware.co.ukd.j.smith.2@bham.ac.ukwangg@for.mat.bham.ac.ukj.ou@bham.ac.ukeg@hep.ph.bham.ac.ukjxh842@bham.ac.ukB.H.Jones@cs.bham.ac.ukandylogsdail@stchem.bham.ac.ukdxh915@bham.ac.ukkee877@bham.ac.uknxg577@bham.ac.uka.utomo@bham.ac.ukPage 25
Page 3: Copyright © The University of Birm
Page 6: ContentsAbstractiiPreface 5Peter Wi
Page 10 and 11: Computational model of affordance-b
Page 12 and 13: Medieval Warfare on the GridThis pr
Page 14 and 15: Chunk Learning and Move Prompting M
Page 16 and 17: Parallel Computation of Braid Orbit
Page 18 and 19: Three-dimensional Numerical Modelli
Page 20 and 21: Micro- and Macromixing Studies in T
Page 22 and 23: Theoretical Studies of the Optical
Page 24 and 25: Evaluation of deformation mechanism

Birmingham Environment for Academic Research - University of ...

Create successful ePaper yourself

Delete template?

Save as template?