Drag Reduction Of Turbulent Flows By Additives

Author : A. Gyr
Publisher : Springer Science & Business Media
ISBN 13 : 9401712956
Total Pages : 243 pages
Book Rating : 4.58/5 ( download)

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Download or read book Drag Reduction of Turbulent Flows by Additives written by A. Gyr and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drag Reduction of Turbulent Flows by Additives is the first treatment of the subject in book form. The treatment is extremely broad, ranging from physicochemical to hydromechanical aspects. The book shows how fibres, polymer molecules or surfactants at very dilute concentrations can reduce the drag of turbulent flow, leading to energy savings. The dilute solutions are considered in terms of the physical chemistry and rheology, and the properties of turbulent flows are presented in sufficient detail to explain the various interaction mechanisms. Audience: Those active in fundamental research on turbulence and those seeking to apply the effects described. Fluid mechanical engineers, rheologists, those interested in energy saving methods, or in any other application in which the flow rate in turbulent flow should be increased.

Author : Feng-Chen Li
Publisher : John Wiley & Sons
ISBN 13 : 1118181115
Total Pages : 233 pages
Book Rating : 4.19/5 ( download)

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Download or read book Turbulent Drag Reduction by Surfactant Additives written by Feng-Chen Li and published by John Wiley & Sons. This book was released on 2012-01-10 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent drag reduction by additives has long been a hot research topic. This phenomenon is inherently associated with multifold expertise. Solutions of drag-reducing additives are usually viscoelastic fluids having complicated rheological properties. Exploring the characteristics of drag-reduced turbulent flows calls for uniquely designed experimental and numerical simulation techniques and elaborate theoretical considerations. Pertinently understanding the turbulent drag reduction mechanism necessities mastering the fundamentals of turbulence and establishing a proper relationship between turbulence and the rheological properties induced by additives. Promoting the applications of the drag reduction phenomenon requires the knowledge from different fields such as chemical engineering, mechanical engineering, municipal engineering, and so on. This book gives a thorough elucidation of the turbulence characteristics and rheological behaviors, theories, special techniques and application issues for drag-reducing flows by surfactant additives based on the state-of-the-art of scientific research results through the latest experimental studies, numerical simulations and theoretical analyses. Covers turbulent drag reduction, heat transfer reduction, complex rheology and the real-world applications of drag reduction Introduces advanced testing techniques, such as PIV, LDA, and their applications in current experiments, illustrated with multiple diagrams and equations Real-world examples of the topic’s increasingly important industrial applications enable readers to implement cost- and energy-saving measures Explains the tools before presenting the research results, to give readers coverage of the subject from both theoretical and experimental viewpoints Consolidates interdisciplinary information on turbulent drag reduction by additives Turbulent Drag Reduction by Surfactant Additives is geared for researchers, graduate students, and engineers in the fields of Fluid Mechanics, Mechanical Engineering, Turbulence, Chemical Engineering, Municipal Engineering. Researchers and practitioners involved in the fields of Flow Control, Chemistry, Computational Fluid Dynamics, Experimental Fluid Dynamics, and Rheology will also find this book to be a much-needed reference on the topic.

Author : Dilafruz Kulmatova
Publisher :
ISBN 13 :
Total Pages : 111 pages
Book Rating : 4.64/5 ( download)

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Download or read book Turbulent Drag Reduction by Additives written by Dilafruz Kulmatova and published by . This book was released on 2013 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: The addition of a minute amount of polymer or surfactant additive to a turbulent fluid flow can result in a large reduction in the frictional drag in pipes and channels. Over the past decades, numerous studies have been carried out on drag reducing additives (DRA). DRA have been successfully applied for potential benefits in various industrial processes, including oil well operations, heating and cooling water circuits, marine and biomedical systems. The use of additives to enhance flow in petroleum pipelines has received the greatest attention due to its great commercial success in reducting cost and energy consumption. Although this effect has been known for almost half a century, the detailed mechanism of drag reduction have still not been clearly identified and is still a subject of ongoing controversy. The aim of this thesis is to develop an understanding of the role of drag reducing agents and to explain the nature of drag reduction mechanism. This could have an impact on the design of efficient pumping systems, the design of drag-reducing agent that are more stable over time, and the modeling of mixing processes that could be an important consideration in designing practical systems.

Author : Albert Gyr
Publisher : Springer Science & Business Media
ISBN 13 : 3642509711
Total Pages : 617 pages
Book Rating : 4.11/5 ( download)

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Download or read book Structure of Turbulence and Drag Reduction written by Albert Gyr and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 617 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1976 a similar titled IUTAM Symposium (Structure of Turbulence and Drag Reduction) was held in Washington . However, the progress made during the last thirteen years as weil as the much promising current research desired a second one this year. In Washington drag reduction by additives and by direct manipulation of the walls (compliant walls and heated surfaces) were discussed. In the meantime it became evident that drag reduction also occurs when turbulence is influenced by geometrical means, e.g. by influencing the pressure distribution by the shape of the body (airfoils) or by the introduction of streamwise perturbances on a body (riblets). In the recent years turbulence research has seen increasing attention being focused on the investigation of coherent structures, mainly in Newtonian fluids. We all know that these structures are a significant feature of turbulent flows, playing an important role in the energy balance in such flows. However their place in turbulence theories as weil as the factors influencing their development are still poorly understood. Consequently, the investigation of phenomena in which the properties of coherent structures are alte red provides a promising means of improving our understanding of turbulent flows in general.

Author : Pouria Baghaei
Publisher :
ISBN 13 :
Total Pages : 135 pages
Book Rating : 4.23/5 ( download)

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Download or read book Drag Reduction with the Aid of Air Bubbles and Additives written by Pouria Baghaei and published by . This book was released on 2009 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of additives on friction loss in upward turbulent flow was investigated in this experimental study. Additives such as air bubbles, frother and polymer were added to water flow to study their influence on the friction factor. In order to perform this research an experimental set-up was designed and developed. The test sections of the set-up consisted of three vertical pipes of different diameters. The set-up was equipped with three pressure transducers, a magnetic flowmeter, gas spargers and a gas rotameter. The first phase of the experimental program involved calibration of the various devices and pipelines test-sections. The single-phase pressure loss data obtained from the pipelines exhibited good agreement with the standard equations. The second phase of the experimental program dealt with the effect of air bubbles and additives (frother and polymer) on drag reduction in turbulent flows. The experimental results showed that bubbles in the range of 1 mm-3 mm increased the wall shear stress. Therefore, no drag-reduction effect was observed. On the contrary, a significant increase in friction factor was observed at low Reynolds numbers as a result of larger bubble sizes and lower turbulence intensities. The friction factor at low Reynolds numbers could be decreased by decreasing the bubble size by addition of frother to the flow system. The combination of polymer and air bubbles showed a drag reduction of up to 60%. It is also evident from the experiment results that the addition of polymer to bubbly flow system leads to fully homogeneous mixture.

Author : K.-S. Choi
Publisher : Springer Science & Business Media
ISBN 13 : 9401135266
Total Pages : 344 pages
Book Rating : 4.69/5 ( download)

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Download or read book Recent Developments in Turbulence Management written by K.-S. Choi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: The European Drag Reduction Meeting has been held on 15th and 16th November 1990 in London. This was the fifth of the annual European meetings on drag reduction in engineering flows. The main objective of this meeting was to discuss up-to-date results of drag reduction research carried out in Europe. The organiser has adopted the philosophy of discussing the yesterday's results rather than the last year's results. No written material has therefore been requested for the meeting. It was only after the meeting the submission of papers was requested to the participants, from which 16 papers were selected for this proceedings volume. The meeting has attracted a record number of participants with a total of 52 researchers from seven European countries, U. K. , France, Germany, the Netherlands, Italy, Switzerland and U. S. S. R. as well as from Japan, Canada and Australia. The subjects covered in this proceedings volume include riblets, LEBUs (Large Eddy Break-Up device), surface roughness, compliant surfaces and polymer additives. Riblets seem to be one of the most extensively studied devices in the past years. Reflecting this situation in the European community, there are six papers on riblets covering their practical applications to aircraft and to a model ship, near-wall coherent structure of the boundary layer and effects of flow three-dimensionality. Possibility of heat-transfer enhancement with riblets and potential use in the laminar flow are also investigated. An analytical model is developed for the boundary-layer with a LEBU device.

Author : Abdulmaik Abdulah Alhusseini
Publisher :
ISBN 13 :
Total Pages : 132 pages
Book Rating : 4.51/5 ( download)

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Download or read book Numerical Simulation of Turbulent Flows with Drag Reducing Polymeric Additives written by Abdulmaik Abdulah Alhusseini and published by . This book was released on 1989 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : David Leonard Wagger
Publisher :
ISBN 13 :
Total Pages : 1772 pages
Book Rating : 4.82/5 ( download)

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Download or read book Turbulent Flow Enhancement by Polyelectrolyte Additives written by David Leonard Wagger and published by . This book was released on 1992 with total page 1772 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Aroon Shenoy
Publisher : Springer Nature
ISBN 13 : 303040045X
Total Pages : 196 pages
Book Rating : 4.53/5 ( download)

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Download or read book Rheology of Drag Reducing Fluids written by Aroon Shenoy and published by Springer Nature. This book was released on 2020-03-25 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: ​This book explains theoretical derivations and presents expressions for fluid and convective turbulent flow of mildly elastic fluids in various internal and external flow situations involving different types of geometries, such as the smooth/rough circular pipes, annular ducts, curved tubes, vertical flat plates, and channels. Understanding the methodology of the analyses facilitates appreciation for the rationale used for deriving expressions of parameters relevant to the turbulent flow of mildly elastic fluids. This knowledge serves as a driving force for developing new ideas, investigating new situations, and extending theoretical analyses to other unexplored areas of the rheology of mildly elastic drag reducing fluids.The book suits a range of functions--it can be used to teach elective upper-level undergraduate or graduate courses for chemical engineers, material scientists, mechanical engineers, and polymer scientists; guide researchers unexposed to this alluring and interesting area of drag reduction; and serve as a reference to all who want to explore and expand the areas dealt with in this book.

Author : Pouria Baghaei
Publisher : LAP Lambert Academic Publishing
ISBN 13 : 9783659219443
Total Pages : 152 pages
Book Rating : 4.44/5 ( download)

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Download or read book Drag Reduction written by Pouria Baghaei and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drag reduction is a remarkable ability to reduce the frictional resistance in the turbulent flow by adding a low concentration of certain additives, drag reducing additive agents (DRA). High costs of fluid transportation (such as pumping the liquids into the pipelines) in production processes has made drag reduction subject of lots of research in the past decades. Several studies have been carried out on reducing the friction factor in flow system using different drag reducing agents. However, there are a few investigations carried out on the effects of combining two or more DRAs. The purpose of this study is to investigate the effects of different additives on drag reduction using various methods. Effects of Polymer, Air bubbles, Aerofroth, and their combination have been investigated through the experimental study.