The Effect of Thixotropy on Pressure Losses in a Pipe
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Bingham Yield Stress and Bingham Plastic Viscosity of Homogeneous Non-Newtonian Slurries
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Cape Peninsula University of Technology BINGHAM YIELD STRESS AND BINGHAM PLASTIC VISCOSITY OF HOMOGENEOUS NON-NEWTONIAN SLURRIES by Brian Tonderai Zengeni Student Number: 210233265 Dissertation submitted in partial fulfilment of the requirements for the degree and which counts towards 50% of the final mark Master of Technology Mechanical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology Supervisor: Prof. Graeme John Oliver Bellville Campus October 2016 CPUT copyright information The dissertation/thesis may not be published either in part (in scholarly, scientific or technical journals), or as a whole (as a monograph), unless permission has been obtained from the University DECLARATION I, Brian Tonderai Zengeni, declare that the contents of this dissertation represent my own unaided work, and that the dissertation has not previously been submitted for academic examination towards any qualification. Furthermore, it represents my own opinions and not necessarily those of the Cape Peninsula University of Technology. October 2016 Signed Date i ABSTRACT This dissertation presents how material properties (solids densities, particle size distributions, particle shapes and concentration) of gold tailings slurries are related to their rheological parameters, which are yield stress and viscosity. In this particular case Bingham yield stresses and Bingham plastic viscosities. Predictive models were developed from analysing data in a slurry database to predict the Bingham yield stresses and Bingham plastic viscosities from their material properties. The overall goal of this study was to develop a validated set of mathematical models to predict Bingham yield stresses and Bingham plastic viscosities from their material properties. -
Mapping Thixo-Visco-Elasto-Plastic Behavior
Manuscript to appear in Rheologica Acta, Special Issue: Eugene C. Bingham paper centennial anniversary Version: February 7, 2017 Mapping Thixo-Visco-Elasto-Plastic Behavior Randy H. Ewoldt Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA Gareth H. McKinley Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA Abstract A century ago, and more than a decade before the term rheology was formally coined, Bingham introduced the concept of plastic flow above a critical stress to describe steady flow curves observed in English china clay dispersion. However, in many complex fluids and soft solids the manifestation of a yield stress is also accompanied by other complex rheological phenomena such as thixotropy and viscoelastic transient responses, both above and below the critical stress. In this perspective article we discuss efforts to map out the different limiting forms of the general rheological response of such materials by considering higher dimensional extensions of the familiar Pipkin map. Based on transient and nonlinear concepts, the maps first help organize the conditions of canonical flow protocols. These conditions can then be normalized with relevant material properties to form dimensionless groups that define a three-dimensional state space to represent the spectrum of Thixotropic Elastoviscoplastic (TEVP) material responses. *Corresponding authors: [email protected], [email protected] 1 Introduction One hundred years ago, Eugene Bingham published his first paper investigating “the laws of plastic flow”, and noted that “the demarcation of viscous flow from plastic flow has not been sharply made” (Bingham 1916). Many still struggle with unambiguously separating such concepts today, and indeed in many real materials the distinction is not black and white but more grey or gradual in its characteristics. -
Regulatory Guide 3.39 Standard Format & Content of License
NUREG-O010 USNRC REGULATORY J GUIDE SERIES REGULATORY GUIDE 3.39 STANDARD FORMAT AND CONTENT OF LICENSE APPLICATIONS FOR PLUTONIUM PROCESSING 2 AND FUEL FABRICATION PLANTS JANUARY 1976 UNITED STATES NUCLEAR REGULATORY COMMISSION Available from National Technical Information Service Springfield, Virginia 22161 Price: Printed Copy $5.50 ; Microfiche $2.25 U.S. NUCLEAR REGULATORY COMMISSION January 1976 REGULATORY GUIDE OFFICE OF STANDARDS DEVELOPMENT REGULATORY GUIDE 3.39 1 STANDARD FORMAT AND C KEN\ OF LICENSE APPLIC 0O1 .R PLUTONIUM PROCf$ L4('I AND FUEL FABRjATI XP lTS USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission. U.S. Nuclear Regulatory Guides are Issued to describe and make available to the public Regulatory Commission. Washington. D.C. 20555. Attention Docketing and methods ecceptable to the NRC staff of implementing specific parts of the Service Section Commission's regulations, to delineate techniques used by the staff in evelu eting specific problems or postulated accidents. or to provide guidance to appli The guides are issued In the following ten broed divisions cants Regulatory Guides are not substitutes for regulations. and compliance 1 wer Reactors 6. Products with them Is not required. Methods end solutions different from those set 2. out in Research and Test Reactors 7. Transponation the guides will be acceptable if they provide a basis for the findings requisite to 3. Fuels and Materiels Facilities I Occupational Health the issuance or continuance of apermit or license by the Commission 4. Evironmental andSiting 9.Antitrust Review Comments and suggestions for Improvements in these guides are encouraged 5. Materials and Plant Protection 10. -
Modification of Bingham Plastic Rheological Model for Better Rheological Characterization of Synthetic Based Drilling Mud
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Covenant University Repository Journal of Engineering and Applied Sciences 13 (10): 3573-3581, 2018 ISSN: 1816-949X © Medwell Journals, 2018 Modification of Bingham Plastic Rheological Model for Better Rheological Characterization of Synthetic Based Drilling Mud Anawe Paul Apeye Lucky and Folayan Adewale Johnson Department is Petroleum Engineering, Covenant University, Ota, Nigeria Abstract: The Bingham plastic rheological model has generally been proved by rheologists and researchers not to accurately represent the behaviour of the drilling fluid at very low shear rates in the annulus and at very high shear rate at the bit. Hence, a dimensionless stress correction factor is required to correct these anomalies. Hence, this study is coined with a view to minimizing the errors associated with Bingham plastic model at both high and low shear rate conditions bearing in mind the multiplier effect of this error on frictional pressure loss calculations in the pipes and estimation of Equivalent Circulating Density (ECD) of the fluid under downhole conditions. In an attempt to correct this anomaly, the rheological properties of two synthetic based drilling muds were measured by using an automated Viscometer. A comparative rheological analysis was done by using the Bingham plastic model and the proposed modified Bingham plastic model. Similarly, a model performance analysis of these results with that of power law and Herschel Buckley Model was done by using statistical analysis to measure the deviation of stress values in each of the models. The results clearly showed that the proposed model accurately predicts mud rheology better than the Bingham plastic and the power law models at both high and low shear rates conditions. -
A Review on Recent Developments in Magnetorheological Fluid Based Finishing Processes
© 2018 JETIR June 2018, Volume 5, Issue 6 www.jetir.org (ISSN-2349-5162) A REVIEW ON RECENT DEVELOPMENTS IN MAGNETORHEOLOGICAL FLUID BASED FINISHING PROCESSES Kanthale V. S., Dr. Pande D. W. College of Engineering Pune, India ABSTRACT-The recent engineering applications demand the use of tough, high intensity and high temperature resistant materials in technology, which evolved the need for newer and better finishing techniques. The conventional machining or finishing methods are not workable for the hard materials like carbides; ceramics, die steel. Magnetorheological fluid assisted finishing process is a new technique under development and becoming popular in this epoch. With the use of external magnetic field, the rheological properties of the MR fluid can be controlled for polishing the surfaces of components. An extended survey of the material removal mechanism and subsequent evolution of analytical MR models are necessary for raising the finishing operation of the MR fluid process. Understanding the influence of various process parameters on the process performance measures such as surface finish and material removal rate. The objective of this study is to do a comprehensive, critical and extensive review of various material removal models based on MR fluid in terms of experimental mechanism, finding the effects of process parameters, characterization and rheological properties of MR fluid. This paper deals with various advancements in MR fluid based process and its allied processes have been discussed in the making the developments in the future in these processes. KEYWORDS: Magnetorheological fluid (MR fluid), Process parameter, Surface roughness, Material removal rate 1. INTRODUCTION The modern engineering applications have necessitated high precision manufacturing. -
World Reference Base for Soil Resources 2014 International Soil Classification System for Naming Soils and Creating Legends for Soil Maps
ISSN 0532-0488 WORLD SOIL RESOURCES REPORTS 106 World reference base for soil resources 2014 International soil classification system for naming soils and creating legends for soil maps Update 2015 Cover photographs (left to right): Ekranic Technosol – Austria (©Erika Michéli) Reductaquic Cryosol – Russia (©Maria Gerasimova) Ferralic Nitisol – Australia (©Ben Harms) Pellic Vertisol – Bulgaria (©Erika Michéli) Albic Podzol – Czech Republic (©Erika Michéli) Hypercalcic Kastanozem – Mexico (©Carlos Cruz Gaistardo) Stagnic Luvisol – South Africa (©Márta Fuchs) Copies of FAO publications can be requested from: SALES AND MARKETING GROUP Information Division Food and Agriculture Organization of the United Nations Viale delle Terme di Caracalla 00100 Rome, Italy E-mail: [email protected] Fax: (+39) 06 57053360 Web site: http://www.fao.org WORLD SOIL World reference base RESOURCES REPORTS for soil resources 2014 106 International soil classification system for naming soils and creating legends for soil maps Update 2015 FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 2015 The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations (FAO) concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specific companies or products of manufacturers, whether or not these have been patented, does not imply that these have been endorsed or recommended by FAO in preference to others of a similar nature that are not mentioned. The views expressed in this information product are those of the author(s) and do not necessarily reflect the views or policies of FAO. -
International Society for Soil Mechanics and Geotechnical Engineering
INTERNATIONAL SOCIETY FOR SOIL MECHANICS AND GEOTECHNICAL ENGINEERING This paper was downloaded from the Online Library of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE). The library is available here: https://www.issmge.org/publications/online-library This is an open-access database that archives thousands of papers published under the Auspices of the ISSMGE and maintained by the Innovation and Development Committee of ISSMGE. 1/18 Liquefaction of Saturated Sandy Soils Liquéfaction de sols sableux saturés by V. A. F lorin , Professor, Doctor of Technical Sciences, Associate Member of the USSR Academy of Sciences, Institute of Mechanics of the USSR Academy of Sciences, and P. L. I vanov , Docent, Candidate of Technical Sciences, Leningrad Polytechnic Institute. Summary Sommaire The authors give results obtained from theoretical and Le présent rapport contient quelques résultats des études experimental research on the liquefaction of saturated sandy théoriques et expérimentales des phénomènes de liquéfaction soils undertaken by them, in the Laboratory of Soil Mechanics de sols sableux saturés qui ont été effectuées aux Laboratoires of the Institute of Mechanics of the U.S.S.R. Academy of Sciences de Mécanique des sols de l’institut de Mécanique de l’Académie and in the Leningrad Polytechnic Institute. des Sciences de l’U.R.S.S. et de l’institut Polytechnique de Laboratory investigations have been carried out on various Leningrad. kinds of disturbances affecting saturated sandy soils and causing Les auteurs décrivent des études de Laboratoire de la liqué their liquefaction. The authors also give the results of studies faction de sols sableux soumis à diverses influences. -
Rough-Wall and Turbulent Transition Analyses for Bingham Plastics
THOMAS, A.D. and WILSON, K.C. Rough-wall and turbulent transition analyses for Bingham plastics. Hydrotransport 17. The 17th International Conference on the Hydraulic Transport of Solids, The Southern African Institute of Mining and Metallurgy and the BHR Group, 2007. Rough-wall and turbulent transition analyses for Bingham plastics A.D. THOMAS* and K.C. WILSON† *Slurry Systems Pty Ltd, Australia †Queens University, Canada Some years ago, the authors developed an analysis of non- Newtonian pipe flow based on enhanced turbulent microscale and associated sub-layer thickening. This analysis, which can be used for various rheologic modelling equations, has in the past been applied to smooth-walled pipes. The present paper extends the analysis to rough walls, using the popular Bingham plastic equation as a representative rheological behaviour in order to prepare friction-factor plots for comparison with measured results. The conditions for laminar-turbulent transition for both smooth and rough walls are also considered, and comparisons are made with earlier correlations and with experimental data. Notation D internal pipe diameter f friction factor (Darcy-Weisbach) fT value of f at laminar-turbulent transition He Hedström number (see Equation [2]) k representative roughness height Re* shear Reynolds number (DU*/) Re*k Reynolds number based on roughness (kU*/ ) ReB Bingham plastic Reynolds number (VD/B) U local velocity at distance y from wall U* shear velocity (͌[o/]) V mean (flow) velocity VN mean (flow) velocity for a Newtonian fluid -
The Effect of Additives and Temperature on the Rheological Behavior of Invert (W/O) Emulsions
The Effect of Additives and Temperature on the Rheological Behavior of Invert (W/O) Emulsions A Thesis Submitted to the College of Engineering Of Nahrain University in Partial Fulfillment Of Requirements for the Degree of Master of Science In Chemical Engineering by Samar Ali Abed Mahammed B.Sc.2004 Moharam 1430 January 2009 Abstract The main aim of this research is to study the effect of temperature on the rheological properties (yield point, plastic viscosity and apparent viscosity) of emulsions by using different additives to obtain the best rheological properties. Twenty seven emulsion samples were prepared; all emulsions in this investigation are direct emulsions when water droplets are dispersed in diesel oil, the resulting emulsion is called water-in-oil emulsion (W/O) invert emulsions. These emulsions including three different volume percentages of barite with three different volume percentages of emulsifier and three different concentrations of asphaltic material under temperatures (77, 122 and 167) °F. The rheological properties of these emulsions were investigated using a couett coaxial cylinder rotational viscometer (Fann-VG model 35 A), by measuring shear stress versus shear rate. By using the Solver Add in Microsoft Excel®, the Bingham plastic model was found to be the best fits the experimental results. It was found that when the temperature increased, it causes a decrease in the rheological properties (yield point, plastic viscosity and apparent viscosity) of emulsions which due to the change in the viscosity of continuous -
Impact of Thixotropy on Flow Patterns Induced in a Stirred Tank
CORE Metadata, citation and similar papers at core.ac.uk Provided by Open Archive Toulouse Archive Ouverte Impact of thixotropy on flow patterns induced in a stirred tank: Numerical and experimental studies G. Couerbe a, D.F. Fletcher b, C. Xuereb a, M. Poux a,∗ a Universit e´ de Toulouse, Laboratoire de G enie´ Chimique, CNRS/INP/UPS, 5 rue Paulin Talabot, BP 1301, 31106 Toulouse Cedex, France b School of Chemical and Biomolecular Engineering, The University of Sydney, NSW 2006, Australia abstract Agitation of a thixotropic shear•thinning fluid exhibiting a yield stress is investigated both experimentally and via simulations. Steady•state experiments are conducted at three 1 impeller rotation rates (1, 2 and 8 s − ) for a tank stirred with an axial•impeller and flow•field measurements are made using particle image velocimetry (PIV) measurements. Three• dimensional numerical simulations are also performed using the commercial CFD code Keywords: ANSYS CFX10.0. The viscosity of the suspension is determined experimentally and is mod• Thixotropy elled using two shear•dependant laws, one of which takes into account the flow instabilities CFD of such fluids at low shear rates. At the highest impeller speed, the flow exhibits the famil• PIV iar outward pumping action associated with axial•flow impellers. However, as the impeller Stirred tank speed decreases, a cavern is formed around the impeller, the flow generated in the vicin• Impeller ity of the agitator reorganizes and its pumping capacity vanishes. An unusual flow pattern, Mixing where the radial velocity dominates, is observed experimentally at the lowest stirring speed. It is found to result from wall slip effects. -
Thixotropy Vs Wall Slip in Suspensions
Thixotropy vs wall slip in suspensions Wonjae Choi Papers : Dullaert, Mewis : Thixotropy : Build-up and breakdown curves during flow ( JoR, 2005 ) Claimed the first robust stress measurement of the thixotropic system Introduced de-embedding of rheometer’s transfer function from the output data Dullaert, Mewis : A model system for thixotropy studies ( Rheol Acta, 2005 ) Detailed description on the previous ‘robust thixotropic system’ Covered various issues which was problematic for previous researches and was reduced with their new compound Covered wall-slip phenomenon and remedy for it Experiments about thixotropy Difficulties in experiments While there are various models & theories about thixotropy, there are few reliable experimental datasets Primary reason for this is the difficulties involved in measuring thixotropic system with enough accuracy Main objective of this paper Building robust thixotropic system which supports repeatible & reliable measurements Recall : Definition of thixotropy in this paper Change of floc structure resulting in varying viscosity Does not necessarily include viselasticity Why is measurement difficult? Implemental artifacts Wall slip Heterogeneous shear rates Gap size effect Rheometer’s transfer function Memory of floc’s microstructure Evaporation of solvents Particle sedimentation, change in particle’s wetting property, adsorption Plan Wall slip Interparticle attraction & PIB Viscosity control Sedimentation Memory Steady-state Enough pre-treatment Evaporation Non volatile suspension -
Non Newtonian Fluids
Non-Newtonian Fluids Non-Newtonian Flow Goals • Describe key differences between a Newtonian and non-Newtonian fluid • Identify examples of Bingham plastics (BP) and power law (PL) fluids • Write basic equations describing shear stress and velocities of non-Newtonian fluids • Calculate frictional losses in a non-Newtonian flow system Non-Newtonian Fluids Newtonian Fluid du t = -µ z rz dr Non-Newtonian Fluid du t = -h z rz dr η is the apparent viscosity and is not constant for non-Newtonian fluids. η - Apparent Viscosity The shear rate dependence of η categorizes non-Newtonian fluids into several types. Power Law Fluids: Ø Pseudoplastic – η (viscosity) decreases as shear rate increases (shear rate thinning) Ø Dilatant – η (viscosity) increases as shear rate increases (shear rate thickening) Bingham Plastics: Ø η depends on a critical shear stress (t0) and then becomes constant Non-Newtonian Fluids Bingham Plastic: sludge, paint, blood, ketchup Pseudoplastic: latex, paper pulp, clay solns. Newtonian Dilatant: quicksand Modeling Power Law Fluids Oswald - de Waele n é n-1 ù æ du z ö æ du z ö æ du z ö t rz = Kç- ÷ = êKç ÷ ú ç- ÷ è dr ø ëê è dr ø ûú è dr ø where: K = flow consistency index n = flow behavior index µeff Note: Most non-Newtonian fluids are pseudoplastic n<1. Modeling Bingham Plastics du t <t z = 0 Rigid rz 0 dr du t ³t t = -µ z ±t rz 0 rz ¥ dr 0 Frictional Losses Non-Newtonian Fluids Recall: L V 2 h = 4 f f D 2 Applies to any type of fluid under any flow conditions Laminar Flow Mechanical Energy Balance Dp DaV 2 + + g Dz + h =Wˆ