DOCSLIB.ORG

Measurement Uncertainty Estimation for Laser Doppler Anemometer

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Measurement Uncertainty Estimation for Laser Doppler Anemometer energies Communication Measurement Uncertainty Estimation for Laser Doppler Anemometer Karolina Weremijewicz 1 and Andrzej Gajewski 2,* 1 Students’ Scientific Society “Heat Engineer”, Faculty of Civil Engineering and Environmental Sciences, Bialystok University of Technology, Wiejska Street 45 A, 15-351 Białystok, Poland; [email protected] 2 Department of HVAC Engineering, Faculty of Civil Engineering and Environmental Sciences, Bialystok University of Technology, Wiejska Street 45 A, 15-351 Białystok, Poland * Correspondence: [email protected]; Tel.: +48-797-995-923 Abstract: Twenty percent of global electricity supplied to the buildings is used for preventing air temperature increase; its consumption for this prevention will triple by 2050 up to China’s present needs. Heat removed from the thermal power plants may drive cold generation in the absorption devices where mass and heat transfer are two-phase phenomena; hence liquid film break-up into the rivulets is extensively investigated, which needs knowledge of the velocity profiles. Laminar flow in a pipe is used in the preliminary study, velocity profile of developed flow is used as a benchmark. The study account writes the applied apparatus with their calibration procedure, and the uncertainty estimation algorithm. The calibration regression line with the slope close to one and a high Pearson’s coefficient value is the final outcome. Therefore, the apparatus may be applied in the principal research. Keywords: liquid film break down; rivulet; velocity profile; laminar flow; surface tension Citation: Weremijewicz, K.; Gajewski, A. Measurement Uncertainty Estimation for Laser Doppler Anemometer. Energies 2021, 1. Introduction 14, 3847. https://doi.org/10.3390/ Crisis in cold generation approaches the world’s economy, for the air conditioners and en14133847 electric fans working against air temperature increase need nearly 20% of the total electrical energy used in buildings in the world. Electricity demands for these purposes is forecasted Academic Editor: Adrian Ilinca to triple by 2050, which would equal China’s present usage [1]. These demands reach the winter and summer peaks. Figure1 shows the former in December and January and the Received: 26 May 2021 latter in July and August; these seasonal peaks concern total energy production and its part Accepted: 23 June 2021 generated in thermal power plants, from fossil fuels combustion, or radioactive decay [2]. Published: 25 June 2021 Thermal power plants, in accordance with the second law of thermodynamics, need to remove heat to a heat sink which can be either surface water or a district heating system. Publisher’s Note: MDPI stays neutral However, in summer time, these systems supply heat only for generating domestic hot with regard to jurisdictional claims in water, which may be insufficient; this insufficiency might be overcome with cold produc- published maps and institutional affil- iations. tion, in the absorption refrigeration systems, from the removed heat temperatures of at least 80 ◦C[3]. In other words, the absorption refrigeration system might utilize heat that is removed from the thermal power plant during electricity generation. Absorption refrigeration systems might alternate from the traditional ones if they are equipped with compact and high-performance heat and mass exchangers [4]. A low usage of the ab- Copyright: © 2021 by the authors. sorption refrigeration systems stems from high ratio between the volume and the cooling Licensee MDPI, Basel, Switzerland. capacity [5]. For this reason, they are also experimentally studied [6,7]. An absorption This article is an open access article refrigerator uses two fluids, which change phases, and concentration flowing through the distributed under the terms and conditions of the Creative Commons absorber, generator, evaporator, and condenser [8,9]. Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Energies 2021, 14, 3847. https://doi.org/10.3390/en14133847 https://www.mdpi.com/journal/energies Energies 2021, 14, 3847 2 of 11 Energies 2021, 14, 3847 2 of 11 1800 1600 1400 1200 1000 800 600 400 Electrical energy production[TWh] 200 0 Thermal power plants Total production Figure 1. A report of International Energy Agency [2] into monthly electricity production. Figure 1. A report of International Energy Agency [2] into monthly electricity production. The change of phase or concentration occurs due to heat and mass transfer in thin liquidThe layers, change which of phase flow or down concentration a solid surface occurs (cf. due Figure to heat 3 in and [4]). mass Firstly, transfer these in layers thin liquidwere investigatedlayers, which because flow down of the a burnoutsolid surface in the (cf. steam Figure boilers 3 in or[4]). distillatory Firstly, these equipment. layers wereHartley investigated and Murgatroyd because [10of ]the investigated burnout in liquid the steam film breakboilers away or distillatory into the rivulets equipment. using Hartleytwo approaches: and Murgatroyd the first [10] one investigated is mechanical liquid equilibrium film break in away the highest into the point rivulets of the using dry twopatch, approaches: which results the first in the one force is mechanical balance in thisequilibrium point named in the stagnation highest point point; of the the other dry patch,method which employs results energy in the minimization, force balance assuming in this point the sum named of kinetic stagnation energy point; across the a other plane methodand the employs surface energy energy approaches minimization, minimum. assuming Bankoff the sum [11] balancedof kineticflow energy rates across and energiesa plane andof the the film surface and energy rivulets approaches at the critical minimum. film thickness; Bankoff it[11] was balanced assumed flow that rates a segment and ener- of giescircle of asthe a film cross-section and rivulets of theat the rivulet, critical and film the thickness; velocity it profiles was assumed in film, that and a in segment each slice of circleof the as rivulet, a cross-section are the same. of the Mikielewicz rivulet, and andthe velocity Moszynski profiles [12,13 in] appliedfilm, and minimization in each slice of of theenergy rivulet, extended are the bysame. surface Mikielewicz energy of and the Mo solid-gasszynski interface.[12,13] applied A common minimization feature of of en- the ergyinvestigations extended by presented surface energy above, inof the this soli paragraph,d-gas interface. is assumed A common laminar feature velocity of the profile in- vestigationsderived by Nusseltpresented (1916) above, (cf. in Madejski this paragraph, [14]); additionally, is assumed Hartley laminar and velocity Murgatroyd profile [de-10] rivedassumed by Nusselt a linear (1916) laminar (cf. profile Madejski for film, [14]); motivated additionally, by surface Hartley shear and only Murgatroyd or a von Karman[10] as- sumeduniversal a linear velocity laminar profile profile for turbulent for film, flow.motivated by surface shear only or a von Karman universalEl-Genk velocity and Saberprofile [15 for] continued turbulent researchflow. into film breakdown, applying the energetic approach;El-Genk their and analysis Saber [15] includes continued a two-dimensional research into film velocity breakdown, profile applying solved using the ener- Ritz geticmethod. approach; Perazzo their and analysis Gratton [includes16] derived a two-dimensional another two-dimensional velocity velocityprofile profile,solved whichusing Ritzis solved method. in closed Perazzo form, and forGratton both the[16] rivulet derived and another film, flowingtwo-dimensional along a vertical velocity plate; profile, the whichcontact is anglesolved was in closed assumed form, to be for either both perpendicularthe rivulet and to film, the flowing plate for along the rivulet a vertical or parallel plate; thefor contact the film. angle While was Tanasijczuk assumed etto al.be [ 17either] derived perpendicular a two-dimensional to the plate velocity for the profile rivulet for or a parallelrivulet pendingfor the film. from While a horizontal Tanasijczuk plate. et al. [17] derived a two-dimensional velocity pro- file forAtaki a rivulet and pending Bart [18] from applied a horizontal a velocity plate. profile for a gravity driven rivulet along an inclined plate in the analysis of their experiments. Another assumption was the static contact angle value 56◦. Energies 2021, 14, 3847 3 of 11 Charogiannis et al. [19] experimentally determined laminar velocity profile for a gravity driven rivulet along an inclined plate for a Reynolds number less than 5.9 and Kapitza number equal to 1.4 following its definition: s Ka = (1) r(g sin an4)1/3 where s is surface tension, g is gravitational acceleration, a is an inclination of film to the horizon, and n is kinematic viscosity; they also obtain a profile for wavy flow forced with frequencies 2 and 6 Hz, when the Reynolds number was about 5.2. The very familiar configurations of the absorbers, applied in the absorption cooling systems, consists of the horizontal tubes, which are covered with falling liquid film; this film is an absorbent solution that, flowing across the tubes, absorbs the vapor of a re- frigerant [4]. The flow divides into three regimes: falling-film flowing around the tubes, droplet-formation flow that occurs on, and in, the vicinity of the lowest tube generatrix, and the droplet-fall flow that appears between two tubes; these regimes exist for LiBr/water [20] and aqueous alkaline nitrate solution [4]. When the absorbent
Load more

Recommended publications
  • A Simultaneous Planar Laser-Induced Fluorescence, Particle Image Velocimetry and Particle Tracking Velocimetry Technique For
    Experimental Thermal and Fluid Science 68 (2015) 516–536 Contents lists available at ScienceDirect Experimental Thermal and Fluid Science journal homepage: www.elsevier.com/locate/etfs A simultaneous planar laser-induced fluorescence, particle image velocimetry and particle tracking velocimetry technique for the investigation of thin liquid-film flows ⇑ Alexandros Charogiannis, Jae Sik An, Christos N. Markides Clean Energy Processes (CEP) Laboratory, Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom article info abstract Article history: A simultaneous measurement technique based on planar laser-induced fluorescence imaging (PLIF) and Received 26 March 2015 particle image/tracking velocimetry (PIV/PTV) is described for the investigation of the hydrodynamic Received in revised form 22 May 2015 characteristics of harmonically excited liquid thin-film flows. The technique is applied as part of an Accepted 8 June 2015 extensive experimental campaign that covers four different Kapitza (Ka) number liquids, Reynolds (Re) Available online 14 June 2015 numbers spanning the range 2.3–320, and inlet-forced/wave frequencies in the range 1–10 Hz. Film thicknesses (from PLIF) for flat (viscous and unforced) films are compared to micrometer stage measure- Keywords: ments and analytical predictions (Nusselt solution), with a resulting mean deviation being lower than the Planar laser-induced fluorescence nominal resolution of the imaging setup (around 20 m). Relative deviations are calculated between Particle image velocimetry l Particle tracking velocimetry PTV-derived interfacial and bulk velocities and analytical results, with mean values amounting to no Harmonically excited films more than 3.2% for both test cases. In addition, flow rates recovered using LIF/PTV (film thickness and Film thickness velocity profile) data are compared to direct flowmeter readings.
    [Show full text]
  • Heat Transfer for Falling Film Evaporation of Black Liquor up To
    International Journal of Heat and Mass Transfer 65 (2013) 907–918 Contents lists available at SciVerse ScienceDirect International Journal of Heat and Mass Transfer journal homepage: www.elsevier.com/locate/ijhmt Heat transfer for falling film evaporation of black liquor up to very high Prandtl numbers q ⇑ Erik Karlsson a, , Mathias Gourdon a, Lars Olausson b, Lennart Vamling a a Energy and Environment, Chalmers University of Technology, Gothenburg, Sweden b Metso Power AB, Gothenburg, Sweden article info abstract Article history: In this study, heat transfer measurements for falling film evaporation were performed up to very high Received 21 January 2013 Prandtl numbers, from 10 to 2800. Black liquor, a residual stream from the pulping process, was used Received in revised form 2 July 2013 as an example of a fluid that can have very high Prandtl numbers. To overcome the problem with fouling, Accepted 3 July 2013 which can be severe for black liquor due to crystal formation at higher concentrations, a new measure- Available online 30 July 2013 ment method has been successfully developed which enables reliable measurements. Viscosity was clearly the most important parameter for the heat transfer coefficient, while the specific mass flow rate Keywords: had a weak and positive dependence. The results were compared with existing heat transfer correlations, Heat transfer but none of them were able to capture the heat transfer behavior of black liquor throughout the whole Falling film Evaporation range of Prandtl numbers. High Prandtl numbers Ó 2013 The Authors. Published by Elsevier Ltd. All rights reserved. High viscosity Black liquor 1. Introduction for having high viscosity and to cause significant problems with fouling.
    [Show full text]
  • A Simultaneous Planar Laser-Induced Fluorescence, Particle Image Velocimetry and Particle Tracking Velocimetry Technique For
    Accepted Manuscript A Simultaneous Planar Laser-Induced Fluorescence, Particle Image Velocime- try and Particle Tracking Velocimetry Technique for the Investigation of Thin Liquid-Film Flows Alexandros Charogiannis, Jae Sik An, Christos N. Markides PII: S0894-1777(15)00164-8 DOI: http://dx.doi.org/10.1016/j.expthermflusci.2015.06.008 Reference: ETF 8497 To appear in: Experimental Thermal and Fluid Science Received Date: 26 March 2015 Revised Date: 22 May 2015 Accepted Date: 8 June 2015 Please cite this article as: A. Charogiannis, J.S. An, C.N. Markides, A Simultaneous Planar Laser-Induced Fluorescence, Particle Image Velocimetry and Particle Tracking Velocimetry Technique for the Investigation of Thin Liquid-Film Flows, Experimental Thermal and Fluid Science (2015), doi: http://dx.doi.org/10.1016/ j.expthermflusci.2015.06.008 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A Simultaneous Planar Laser-Induced Fluorescence, Particle Image Velocimetry and Particle Tracking Velocimetry Technique for the Investigation of Thin Liquid-Film Flows Alexandros Charogiannis, Jae Sik An and Christos N. Markides* Clean Energy Processes (CEP) Laboratory, Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom * Correspondent author: [email protected] Abstract A simultaneous measurement technique based on planar laser-induced fluorescence imaging (PLIF) and particle image/tracking velocimetry (PIV/PTV) is described for the investigation of the hydrodynamic characteristics of harmonically excited liquid thin-film flows.
    [Show full text]
  • Augmented Skew-Symetric System for Shallow-Water System With
    Augmented Skew-Symetric System for Shallow-Water System with Surface Tension Allowing Large Gradient of Density Didier Bresch, Nicolas Cellier, Frédéric Couderc, Marguerite Gisclon, Pascal Noble, Gaël Loïc Richard, Christian Ruyer-Quil, Jean-Paul Vila To cite this version: Didier Bresch, Nicolas Cellier, Frédéric Couderc, Marguerite Gisclon, Pascal Noble, et al.. Augmented Skew-Symetric System for Shallow-Water System with Surface Tension Allowing Large Gradient of Density. 2020. hal-02382372v2 HAL Id: hal-02382372 https://hal.archives-ouvertes.fr/hal-02382372v2 Preprint submitted on 9 Jun 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Augmented Skew-Symetric System for Shallow-Water System with Surface Tension Allowing Large Gradient of Density D. Bresch, N. Cellier, F. Couderc, M. Gisclon, P. Noble, G.–L. Richard, C. Ruyer-Quil, J.–P. Vila June 9, 2020 Abstract In this paper, we introduce a new extended version of the shallow-water equations with surface tension which may be decomposed into a hyperbolic part and a second order derivative part which is skew- symmetric with respect to the L2 scalar product. This reformulation allows for large gradients of fluid height simulations using a splitting method.
    [Show full text]
  • Direct Effect of Solvent Viscosity on the Physical Mass Transfer for Wavy Film Flow in a Packed Column
    Direct effect of solvent viscosity on the physical mass transfer for wavy film flow in a packed column Zhijie Xu1, a), Rajesh Kumar Singh2, Jie Bao2 and Chao Wang1 1Physical and Computational Sciences Directorate, 2Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA ABSTRACT The interphase mass transfer plays a critical role in determining the height of packed column used in 2 absorption process. In a recent experiments , the direct impact of viscosity ( ) on the physical mass transfer coefficient ( ) was observed to be higher in a packed column as compared to the wetted wall column. We offer a plausible mechanism involving the wavy film and eddy enhanced mass transfer in a packed column to explain underlying physics via analytical and numerical studies. The analytically derived mass transfer coefficient matches well with experimental observation in a packed column. The countercurrent flow simulations in a packed column with both uniform and wavy films also confirm this behavior. The predicted shows steep variation with for a wavy film than a uniform film, further confirms the proposed theory. A similar relation ( ~ . ) for a wavy film is also observed in −0 38 theoretical, experimental and numerical studies. Keywords: Mass transfer, viscosity, wavy film, eddy diffusion, carbon capture 1. Introduction Solvent absorption by countercurrent flow in a packed column is a promising technology for 3-5 mitigating carbon dioxide (CO2) emissions from power plants . The structured packings provides a large surface area for mass transfer while minimizing pressure drop across the column as compared to random packings 6. Before deploying this technology to industry, its performance and scalability needs to be investigated 7.
    [Show full text]
  • An Investigation of Droplets and Films Falling Over Horizontal Tubes
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1-1-2003 An investigation of droplets and films falling vo er horizontal tubes Jesse David Killion Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Recommended Citation Killion, Jesse David, "An investigation of droplets and films falling vo er horizontal tubes" (2003). Retrospective Theses and Dissertations. 19454. https://lib.dr.iastate.edu/rtd/19454 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. An investigation of droplets and films falling over horizontal tubes by Jesse David Killion A thesis submitted to the graduate faculty in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Major: Mechanical Engineering Program of Study Committee: Srinivas Garimella, Major Professor Richard H. Pletcher James C. Hill Iowa State University Ames, Iowa 2003 Copyright OO Jesse David Killion, 2003. All rights reserved. 11 Graduate College Iowa State University This is to certify that the master's thesis of Jesse David Killion has met the thesis requirements of Iowa State University Signatures have been redacted for privacy 111 TABLE OF CONTENTS ABSTRACT V ACKNOWLEDGEMENTS
    [Show full text]
  • Numerical Solution for Kapitza Waves on a Thin Liquid Film
    J. Braz. Soc. Mech. Sci. Eng. manuscript No. (will be inserted by the editor) Numerical solution for Kapitza waves on a thin liquid film Bruno Pelisson Chimetta · Mohammad Zakir Hossain · Erick de Moraes Franklin Received: date / Accepted: date Abstract The flow of a liquid film over an inclined plane is frequently found in na- ture and industry, and, under some conditions, instabilities in the free surface may appear. These instabilities are initially two-dimensional surface waves, known as Kapitza waves. Surface waves are important to many industrial applications. For ex- ample, liquid films with surface waves are employed to remove heat from solid sur- faces. The initial phase of the instability is governed by the Orr-Sommerfeld equation and the appropriate boundary conditions; therefore, the fast and accurate solution of this equation is useful for industry. This paper presents a spectral method to solve the Orr-Sommerfeld equation with free surface boundary conditions. Our numerical approach is based on a Galerkin method with Chebyshev polynomials of the first kind, making it possible to express the Orr-Sommerfeld equation and their boundary conditions as a generalized eigenvalue problem. The main advantages of the present spectral method when compared to others such as, for instance, spectral collocation, are its stability and its readiness in including the boundary conditions in the dis- cretized equations. We compare our numerical results with analytical solutions based on Perturbation Methods, which are valid only for long wave instabilities, and show that the results agree in the region of validity of the long-wave hypothesis. Far from This is a post-peer-review, pre-copyedit version of an article published in Journal of the Brazilian Society of Mechanical Sciences and Engineering, 40: 375, 2018.
    [Show full text]
  • Dynamics and Stability of a Non-Newtonian Falling Film Symphony Chakraborty
    Dynamics and stability of a non-Newtonian falling film Symphony Chakraborty To cite this version: Symphony Chakraborty. Dynamics and stability of a non-Newtonian falling film. Mechanics [physics.med-ph]. Université Pierre et Marie Curie - Paris VI, 2012. English. NNT : 2012PAO66368. tel-00828305 HAL Id: tel-00828305 https://tel.archives-ouvertes.fr/tel-00828305 Submitted on 30 May 2013 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Dynamics and stability of a non-Newtonian falling film SYMPHONY CHAKRABORTY 2nd July 2012 Laboratoire FAST - UMR 7608 (UPMC-UPS-CNRS) Bat. 502 - Campus Universitaire 91405 Orsay Cedex, FRANCE. Submitted on 7th May 2012 in partial fulfillment of the requirements for the degree of Doctor of Philosophy UPMC Paris VI, FRANCE. Members of Jury: Dr. Neil RIBE Director Dr. Christian RUYER-QUIL Co-Supervisor Dr. Valéry BOTTON Reviewer Prof. Richard CRASTER Reviewer Prof. Huai-Zhi LI Examiner Dr. Maurice ROSSI Examiner Dynamique et stabilité d’un film tombant non-Newtonien SYMPHONY CHAKRABORTY soutenance prévue le 2 Juillet 2012 Laboratoire FAST - UMR 7608 (UPMC-UPS-CNRS) Bat. 502 - Campus Universitaire 91405 Orsay Cedex, FRANCE. Soumis le 7 Mai 2012 UPMC Paris VI, FRANCE.
    [Show full text]
  • Hydrodynamics and Heat Transfer in Vertical Falling Films with Smooth and Modified Heat-Transfer Surfaces an Experimental
    THESIS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Hydrodynamics and Heat Transfer in Vertical Falling Films with Smooth and Modified Heat-Transfer Surfaces – An Experimental and Numerical Investigation ANDERS ÅKESJÖ Department of Chemistry and Chemical Engineering CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden 2018 Hydrodynamics and Heat Transfer in Vertical Falling Films with Smooth and Modified Heat-Transfer Surfaces – An Experimental and Numerical Investigation ANDERS ÅKESJÖ ISBN 978-91-7597-816-1 © ANDERS ÅKESJÖ, 2018 Doktorsavhandlingar vid Chalmers tekniska högskola Ny serie nr 4497 ISSN 0346-718X CHALMERS UNIVERSITY OF TECHNOLOGY Department of Chemistry and Chemical Engineering SE-412 96 Gothenburg Sweden Phone: +46 (0)31-772 10 00 Cover: Photographs of the falling film on a smooth (Left) and a modified (Right) heat transfer surface in the Atmospheric setup. The close-ups show the temperature contour plot inside the liquid film flow obtained from the numerical framework. Printed by Chalmers Reproservice CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden 2018 Hydrodynamics and Heat Transfer in Vertical Falling Films with Smooth and Modified Heat-Transfer Surfaces – An Experimental and Numerical Investigation ANDERS ÅKESJÖ Forest Products and Chemical Engineering Department of Chemistry and Chemical Engineering Chalmers University of Technology ABSTRACT High energy utilization efficiency is important to achieve a sustainable society. By having highly efficient heat exchangers, more energy can be recovered and reused at a lower cost. One commonly used type of heat exchangers is a vertical falling film unit, which is a device where a thin liquid film is flowing down a vertical wall in the presence of a gas layer. Such units can operate with small temperature differences and have short residence times and small pressure losses.
    [Show full text]
  • Characterisation of an Analogue Liquid for Hydrodynamic Studies of Gas-Ionic Liquid Flows
    CHARACTERISATION OF AN ANALOGUE LIQUID FOR HYDRODYNAMIC STUDIES OF GAS-IONIC LIQUID FLOWS Barry J. Azzopardia, Ezekiel O. Agunlejikaa, Donglin Zhaoa, *, Ryuhei Kajia, Buddhika N. Hewakandambya a Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom b School of Engineering, London South Bank University, London, SE1 0AA, United Kingdom ABSTRACT Ionic liquids are liquid salts at low temperatures (normally less than 100°C). They are powerful solvents with very low vapour pressure. They have great potentials in many applications such as gas absorption and chemical synthesis. However, they are expensive. This limits extensive studies towards establishing phenomenological models. To address this limitation, an analogue liquid, with properties similar to an ionic liquid, has been identified which on the grounds of cost and safety appears to be suitable. In this paper, the hydrodynamic behaviour of an ionic liquid in a bubble column is compared with those of water and other liquids with similar physical properties. Average gas holdup, bubble coalescence, bubble size and specific interfacial area with different liquids are examined. Gas hold-up was determined by monitoring the change of conductivity between two flush mounted rings. The differences in bubble size and coalescence are revealed by analysing the stills taken from a high speed video camera. The dominant flow pattern in a small diameter column with ionic liquids or other fluids having similar viscosity is slug flow. The small bubbles in the liquid slugs make a smaller contribution to the specific interfacial area than Taylor bubbles. It is observed that Taylor bubbles can coalesce. The hydrodynamics of an ionic liquid in a bubble column can be estimated from that of a fluid with similar physical properties.
    [Show full text]
  • Experimental Study of Falling Films by Simultaneous Laser-Induced Fluorescence, Particle Image Velocimetry and Particle Tracking Velocimetry
    17th International Symposium on Applications of Laser Techniques to Fluid Mechanics Lisbon, Portugal, 07-10 July, 2014 Experimental Study of Falling Films by Simultaneous Laser-Induced Fluorescence, Particle Image Velocimetry and Particle Tracking Velocimetry Alexandros Charogiannis1 and Christos N. Markides1,* 1: Clean Energy Processes Laboratory, Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom * Correspondent author: [email protected] Abstract A measurement technique based on the simultaneous implementation of Laser-Induced Fluorescence (LIF), Particle Image Velocimetry (PIV) and Particle Tracking Velocimetry (PTV) has been applied to the study of wavy liquid falling film flows characterized by low Reynolds (Re) and Kapitza (Ka) numbers. The presently examined Re number range was 2.2 – 8.2, while the Ka number range was 28.6 – 41.4. The experimental methodology was developed with the ultimate aim of allowing for the evaluation of the local and instantaneous film thickness, interfacial velocity and velocity field from within the illuminated liquid volume underneath the wavy interface. The major challenges associated with the simultaneous implementation of the two optical diagnostic techniques were, firstly, the development of a refractive index correction approach allowing for liquids of different properties (surface tension and viscosity) to be tested, secondly, the identification of the location of the two liquid boundaries (solid-liquid and gas- liquid) in the LIF images, and lastly,
    [Show full text]
  • Proquest Dissertations
    Two Cases of Symmetry Breaking of Free Surface Flows Hamid AIT ABDERRAHMANE A thesis In The department of Mechanical and Industrial Engineering Presented in Partial Fulfilment of the Requirements For the Degree of Doctor Philosophy (Mechanical Engineering) at Concordia University Montreal, Quebec, Canada November 2008 © Hamid Ait Abderrahmane , 2008 Library and Archives Bibliothgque et 1*1 Canada Archives Canada Published Heritage Direction du Branch Patrimoine de l'6dition 395 Wellington Street 395, rue Wellington Ottawa ON K1A0N4 Ottawa ON K1A0N4 Canada Canada Your file Votre r6f6rence ISBN: 978-0-494-63388-5 Our file Notre r6f6rence ISBN: 978-0-494-63388-5 NOTICE: AVIS: The author has granted a non- L'auteur a accorde une licence non exclusive exclusive license allowing Library and permettant a la Bibliotheque et Archives Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par telecommunication ou par I'lnternet, preter, telecommunication or on the Internet, distribuer et vendre des theses partout dans le loan, distribute and sell theses monde, a des fins commerciales ou autres, sur worldwide, for commercial or non- support microforme, papier, electronique et/ou commercial purposes, in microform, autres formats. paper, electronic and/or any other formats. The author retains copyright L'auteur conserve la propriete du droit d'auteur ownership and moral rights in this et des droits moraux qui protege cette these. Ni thesis. Neither the thesis nor la these ni des extraits substantiels de celle-ci substantial extracts from it may be ne doivent etre imprimes ou autrement printed or otherwise reproduced reproduits sans son autorisation.
    [Show full text]