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Thursday, August 6, 2020 | History

2 edition of comparative study of methods of assessing hydrodynamic drag reducing polymers. found in the catalog.

comparative study of methods of assessing hydrodynamic drag reducing polymers.

John Craig McIlwrath

comparative study of methods of assessing hydrodynamic drag reducing polymers.

by John Craig McIlwrath

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Published .
Written in English


Edition Notes

Thesis (Ph.D.)--The Queen"s University of Belfast, 1978.

The Physical Object
Pagination1 v
ID Numbers
Open LibraryOL19318350M

TABLE OF CONTENTS Page List of Tables vii List of Figures viii List of Symbols ix Introduction 2 Theory and Literature review 7 Friction Factor 7 Drag Reduction 11 Friction Factor 11 Mechanism 12 Onset of Drag Reduction 16 Polymer Degradation 16 Materials and Methods 19 Experimental Set-up 19 Determination of Flow Parameters 22 Reynolds. The aim of this study was to analyse the effect in hydrodynamic drag forces when different body positions are applied during underwater gliding after starts and turns in swimming. Main data suggested that the positions with the arms fully extended at the front of the body presented lower drag values than the position with the arms aside the trunk.

A novel hydrodynamic approach of drag-reducing polymers to improve left ventricular hypertrophy and aortic remodeling in spontaneously hypertensive rats Xinlu Zhang,1,* Xu Wang,2,* Feng Hu,1 Boda Zhou,3 Hai-Bin Chen,1 Daogang Zha,1 Yili Liu,1 Yansong Guo,4 Lemin Zheng,2 Jiancheng Xiu1 1Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, 2The . polymers to control self-assembly, prevent aggregation, and promote incorporation into polymer matrices and biological systems. The hydrodynamic diameter of these nanoparticle–polymer complexes is a critical factor for many applications, and predicting this size is complicated by the.

Blood-soluble drag reducing polymers (DRPs) have been shown to produce considerable beneficial effects on blood circulation, including an increase in tissue perfusion and tissue oxygenation and a decrease in vascular resistance, when injected in blood at minute concentrations in animal models of normal and especially pathological circulation. Drag is the component of a force acting on a body that is projected along the direction of motion. Both shear forces and pressure induce drag on a body in motion. Shear forces, known as skin friction drag, are more significant in streamlined objects, while the pressure drag is more significant in blunt objects [5]. Fig. (1) shows the net drag.


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Comparative study of methods of assessing hydrodynamic drag reducing polymers by John Craig McIlwrath Download PDF EPUB FB2

Mitigation of Hydrodynamic Resistance: Methods to Reduce Hydrodynamic Drag [PERLIN, MARC, CECCIO, STEVEN] on *FREE* shipping on qualifying offers. Mitigation of Hydrodynamic Resistance: Methods to Reduce Hydrodynamic DragCited by: 5. A comparative study of methods of assessing hydrodynamic drag reducing polymers.

Author: McIlwrath, J. Awarding Body: Queen's University Belfast Current Institution: Queen's University Belfast Date of Award: Availability of Full Text. The influence of the size of polymer particles and their number in the deformed fluid volume on the Thoms effect is examined in an example of Author: I.

Uskov, E. Uskova, N. Belova. The study included a review of drag reduction phenomenology, the development of continuum models of the dynamics of dilute polymer solutions, the introduction of a simple theory of. ResearchArticle Parameters of Drag Reducing Polymers and Drag Reduction Performance in Single-Phase Water Flow ar,-Hashmi,-Wahaibi,-Wahaibi,-Ajmi,i.

Drag reduction is the increase in pumpability of a fluid caused by the small amount of additives. Practically, adding a small concentration of the drag reducing polymers (DRPs) to the carrier fluid reduces the friction of the fluid and increases the capacity of pipeline without changing the pipelines flow conditions [].This phenomenon of the DRPs has been applied in the transportation of crude.

Mohammad Ahmadzadehtalatapeh, Majid Mousavi / A Review on the Drag reduction Methods of the Ship Hulls for Improving the Hydrodynamic Performance 52 and its optimization, air lubrication, and fouling and coatings.

For every category, the related studies and reports have been reviewed and discussed in the sub sections. Reviews on drag reducing polymers Korean J. Chem. Eng.(Vol. 32, No. 8) i ts s k in ex h ib i ts ri b le t s tr uc t ur e s t h at a l ig n t o th e f l o w d i r ec ti o n t o.

Abstract −Polymers are effective drag reducers owing to their ability to suppress the formation of turbulent eddies at low concentrations. Existing drag reduction methods can be generally classified into additive and non-additive tech-niques.

The polymer additive based method is categorized under additive techniques. Other drag reducing additives. Arora et al. [7] investigated the effect of a drag reducing cationic surfactant on turbulent swirling flows generated in a cylindrical cavity by a rotating disk.

While, Petrie et al. [8] studied the effects of surface roughness on polymer drag reduction in a zero-pressure gradient flat plate turbulent boundary layer.

2 Flow Loop and Instrumentation. In the study presented here, Aloe vera-based drag reducing polymer (AV-DRP), a blood soluble DRP with great potential for clinical applications, was characterized and evaluated using chemical, rheological and hydrodynamic methods. AV-DRP offered the advantage of biocompatibility and resistance to mechanical stresses which induce degradation to.

The effect of Polyox, Separan and CMC drag-reducing polymers on the rate of electrochemical mass transfer was studied using the cathodic reduction of K3Fe(CN)6 in neutral media at a rotating cylinder cathode. Reynolds number and polymer concentration were varied over the ranges – and 10– ppm respectively.

Under these conditions it was found that the three polymers reduce the. Drag-reducing polymers (DRPs) are long-chain, To assess the effect of DRPs on microcirculation in vivo, another 20 male Sprague–Dawley rats (– g) were used for hydrodynamic study. Among them, 10 were given the same 75 μg/ g dose of PEO solution while the other 10 were given isovolumic normal saline.

The study included a review of drag reduction phenomenology, the development of continuum models of the dynamics of dilute polymer solutions, the introduction of a simple theory of poly-hydrodynamic turbulence and a discussion of its implications for grid flows, and consideration of optimizing polymer architecture.

The formal discovery of drag reduction using polymers is attributed to Toms () during experiments on the degradation of polymers in pump. Since then, a lot of research for both practical and fundamental purposes has been going on to further understand and adequately utilize this phenomenon resulting probably in thousands of papers in both single and multiphase phase flows.

Mechanical degradation of DRP is defined as the loss of effectiveness in polymer drag-reducing ability that is not regained once mechanical stress is removed. 29 In our study, PEO degradation was evaluated via reduction in drag-reducing efficiency and polymer solution viscosity.

Four experiments were performed (two for each pump), and small. between drag-reducing polymers and surfactants were studied. The drag-reducing polymers studied were nonionic polyethylene oxide (referred to as PEO) and anionic copolymer of acrylamide and sodium acrylate (referred to as CPAM).

The drag-reducing surfactants studied were nonionic ethoxylated alcohol - Alfonic (referred to as EA), cationic. Polymers are effective drag reducers owing to their ability to suppress the formation of turbulent eddies at low concentrations. Existing drag reduction methods can be generally classified into additive and non-additive techniques.

The polymer additive based method is. The hydrodynamic retention for HPAM polymers was fairly reported in the literature [27,28].

So far, there is no study reported the hydrodynamic retention performance of the sulfonated polymers. This study focuses on the interaction between the sulfonated polyacrylamide polymers and rock surfaces of Bentheimer cores at various flow rates. In this paper, the method of fabricating artificial composite drag reduction surface based on biological sharkskin morphology and mucus nano-long chain is investigated and studied, the chemical, mechanical and hydrodynamic properties are explored from different aspects in depth, in which, the experimental results in water tunnel showed that the.

WE report here on one of many anomalies which occur when drag-reducing polymers are dissolved in water1–4: the damping of manometer-type oscillations. Figure 1: Adding polymer to a fluid is known to reduce drag, but the effectiveness was thought to taper off beyond a certain concentration called the maximum drag reduction asymptote (dotted line.) Hof and colleagues carefully measured the friction factor (f) in a liquid for different polymer concentrations (C) and Reynolds numbers (Re).They uncovered a window of C and Re values in .The total coefficient of hydrodynamic resistance Ch = Rh / displacement for an object moving close to the surface is defined as: Ch= Cw.(Fr) + Cv.(Re.

K/L) If this object is shaped to "Fly" (foils hydrofoils) in water, we can make a study of classical aerodynamic lift and drag. Cd and CL (drag and lift coefficients) are given according to.