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dc.contributor.author
Gkoutzamanis, Vasileios
en
dc.date.accessioned
2015-05-30T12:43:31Z
dc.date.available
2015-09-27T05:56:33Z
dc.date.issued
2015-05-30
dc.identifier.uri
https://repository.ihu.edu.gr//xmlui/handle/11544/135
dc.rights
Default License
dc.title
Numerical study of gas-solid flow in a cyclone separator
en
heal.type
masterThesis
heal.secondaryTitle
A CFD investigation
en
heal.language
en
heal.access
free
el
heal.license
http://creativecommons.org/licenses/by-nc/4.0
heal.recordProvider
School of Science and Technology, MSc in Energy Systems
heal.publicationDate
2014-11
heal.bibliographicCitation
Gkoutzamanis Vasileios, 2014, Numerical study of gas-solid flow in a cyclone separator: A CFD investigation ,Master's Dissertation, International Hellenic University
en
heal.abstract
This dissertation was written as a part of the MSc in Energy Systems at the International Hellenic University. Its objective was to examine the flow behavior of cyclone separators that are used as gas cleaners in biomass industries and other industrial applications and exploit the derived gas as an energy source. The fundamental physics that inhere in the pattern of a fluid flow can be the essential tool for the improvement of cyclone performance. The physics of a flow field inside a cyclone is characterized by high complexity, the laws of which are expressed by partial differential equations that are not susceptible by analytical solutions. However they can be solved numerically and this is why commercially available Computational Fluid Dynamics programs are used to perform calculations and evaluate the performance of the cyclone. The work done in this thesis aims to evaluate the most appropriate model used in Computational Fluid Dynamics that describes accurately the flow field of a cyclone as regards a two-phase flow that consists of particles and gas. K-ε and RSM simulations are mainly undertaken with the latter being the most accurate. It is concluded that it is mandatory that Random Discrete Walk Model should be used in combination with a Reynolds Stress Model for a variety of particles injected into the cyclone.
en
heal.tableOfContents
ABSTRACT ........................................................................................................................... I PREFACE ......................................................................................................................... VIII 1. INTRODUCTION ...................................................................................................... 1 1.1 What is a cyclone .................................................................................................................................. 1 1.2 The Cyclone geometry .......................................................................................................................... 3 1.3 Classification of study approaches ....................................................................................................... 4 1.3.1 Analytical methods ................................................................................................................................... 5 1.3.2 Experimental measurements ................................................................................................................ 6 1.4 Literature review .................................................................................................................................... 7 1.5 How the cyclone works - Particle flow................................................................................................. 8 1.5.1 Particle separation ................................................................................................................................... 8 1.5.2 Separation Efficiency .............................................................................................................................10 1.5.3 Pressure drop ..........................................................................................................................................12 2. CHAPTER 2 - COMPUTATIONAL FLUID DYNAMICS ....................................14 2.1 Review ................................................................................................................................................. 14 2.2 Solving the gas flow field ................................................................................................................. 16 2.3 Classification of Multiphase flows ...................................................................................................... 17 2.4 Particle Motion in Fluids-Discrete phase modeling .......................................................................... 18 2.4.1 Drag Force ...............................................................................................................................................18 2.4.2 Pressure Gradient and Buoyancy Force ............................................................................................21 2.4.3 Added Mass and Basset Force............................................................................................................22 2.4.4 Body Forces ..............................................................................................................................................22 2.4.5 Slip-Shear Lift Force ...............................................................................................................................23 2.4.6 Slip-Rotation Lift Force ..........................................................................................................................24 2.4.7 Torque .......................................................................................................................................................25 2.4.8 Response Time and Stokes Number .................................................................................................25 2.5 Predicting particle deposition within a Lagrangian framework ....................................................... 26 2.6 Particle-Wall Collisions ........................................................................................................................ 27 2.6.1 Velocity Change during Wall Collisions .............................................................................................28 2.6.2 Wall Roughness Effects ........................................................................................................................28 Numerical study of gas-solid flow in a cyclone separator: A CFD investigation V. Gkoutzamanis Page iv 2.7 Particle-particle collisions .................................................................................................................... 29 3. CHAPTER 3 – TURBULENCE – SOLUTION PROCEDURE .............................30 3.1 Turbulence ........................................................................................................................................... 30 3.2 Turbulence models .............................................................................................................................. 31 3.2.1 Reynolds Averaged Navier Stokes (RANS) Turbulence models ..................................................31 3.2.2 Eddy Simulations ....................................................................................................................................34 3.3 Procedure ............................................................................................................................................. 35 3.4 Meshing ................................................................................................................................................ 37 4. CHAPTER 4 – SIMULATIONS – TURBULENT FLOW ......................................39 4.1 Simulation Conditions ......................................................................................................................... 39 4.2 Initial conditions – Case 1 .................................................................................................................. 40 4.3 Case 2,3,4,5 analysis .......................................................................................................................... 42 4.4 Case 6, 7,8,9,10,11 analysis.............................................................................................................. 47 4.5 Case 12-13-14 analysis ...................................................................................................................... 54 4.6 Case 15-16-17 analysis .................................................................................................................... 58 5. CHAPTER 5 – CONCLUSIONS .............................................................................62 6. REFERENCES ...........................................................................................................66
en
heal.advisorName
Sardi, Prof. Dr. Aikaterini
en
heal.committeeMemberName
Sardi, Prof. Dr. Aikaterini
en
heal.committeeMemberName
Tompoulidis
en
heal.committeeMemberName
Martinopoulos
en
heal.academicPublisher
School of Science &Technology, Master of Science (MSc) in Energy Systems
en
heal.academicPublisherID
ihu
heal.numberOfPages
80
heal.fullTextAvailability
true


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