CT findings of a unicameral calcaneal bone cyst containing a fluid-fluid level.

Science.gov (United States)

Gallagher, Thomas A; Lim-Dunham, Jennifer E; Vade, Aruna

2007-03-01

Calcaneal unicameral bone cysts often contain fluid, but rarely contain fluid-fluid levels. We present a case focusing on the CT findings of a large calcaneal bone cyst with a fluid-fluid level and a review of the literature.

Atomistic Modeling of the Fluid-Solid Interface in Simple Fluids

Science.gov (United States)

Hadjiconstantinou, Nicolas; Wang, Gerald

2017-11-01

Fluids can exhibit pronounced structuring effects near a solid boundary, typically manifested in a layered structure that has been extensively shown to directly affect transport across the interface. We present and discuss several results from molecular-mechanical modeling and molecular-dynamics (MD) simulations aimed at characterizing the structure of the first fluid layer directly adjacent to the solid. We identify a new dimensionless group - termed the Wall number - which characterizes the degree of fluid layering, by comparing the competing effects of wall-fluid interaction and thermal energy. We find that in the layering regime, several key features of the first layer layer - including its distance from the solid, its width, and its areal density - can be described using mean-field-energy arguments, as well as asymptotic analysis of the Nernst-Planck equation. For dense fluids, the areal density and the width of the first layer can be related to the bulk fluid density using a simple scaling relation. MD simulations show that these results are broadly applicable and robust to the presence of a second confining solid boundary, different choices of wall structure and thermalization, strengths of fluid-solid interaction, and wall geometries.

Synovial fluid analysis

Science.gov (United States)

Joint fluid analysis; Joint fluid aspiration ... El-Gabalawy HS. Synovial fluid analysis, synovial biopsy, and synovial pathology. In: Firestein GS, Budd RC, Gabriel SE, McInnes IB, O'Dell JR, eds. Kelly's Textbook of ...

Editorial Special Issue on Fluid Mechanics and Fluid Power (FMFP ...

Indian Academy of Sciences (India)

This special issue of Sadhana contains selected papers from two conferences related to fluid mechanics held in India recently, Fluid Mechanics and Fluid Power conference at NIT, Hamirpur, and an International Union of Theoretical ... A simple, well thought out, flow visualization experiment or a computation can sometimes ...

FOREWORD Fluid Mechanics and Fluid Power (FMFP)

Indian Academy of Sciences (India)

This section of the Special Issue carries selected articles from the Fluid Mechanics and Fluid. Power Conference held during 12–14 December 2013 at the National Institute of Technology,. Hamirpur (HP). The section includes three review articles and nine original research articles. These were selected on the basis of their ...

statistical fluid theory for associating fluids containing alternating ...

Indian Academy of Sciences (India)

Statistical associating fluid theory of homonuclear dimerized chain fluids and homonuclear ... The proposed models account for the appropriate .... where gHNM(1,1) is the expression for the contact value of the correlation func- tion of two ...

Fluid inclusion geothermometry

Science.gov (United States)

Cunningham, C.G.

1977-01-01

Fluid inclusions trapped within crystals either during growth or at a later time provide many clues to the histories of rocks and ores. Estimates of fluid-inclusion homogenization temperature and density can be obtained using a petrographic microscope with thin sections, and they can be refined using heating and freezing stages. Fluid inclusion studies, used in conjunction with paragenetic studies, can provide direct data on the time and space variations of parameters such as temperature, pressure, density, and composition of fluids in geologic environments. Changes in these parameters directly affect the fugacity, composition, and pH of fluids, thus directly influencing localization of ore metals. ?? 1977 Ferdinand Enke Verlag Stuttgart.

Buffer fluid

Energy Technology Data Exchange (ETDEWEB)

Mirzadzhanzade, A Kh; Dedusanko, G Ya; Dinaburg, L S; Markov, Yu M; Rasizade, Ya N; Rozov, V N; Sherstnev, N M

1979-08-30

A drilling fluid is suggested for separating the drilling and plugging fluids which contains as the base increased solution of polyacrylamide and additive. In order to increase the viscoelastic properties of the liquid with simultaneous decrease in the periods of its fabrication, the solution contains as an additive dry bentonite clay. In cases of the use of a buffer fluid under conditions of negative temperatures, it is necessary to add to it table salt or ethylene glycol.

Fluid Shifts

Science.gov (United States)

Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.;

Computational Fluid Dynamics

International Nuclear Information System (INIS)

Myeong, Hyeon Guk

1999-06-01

This book deals with computational fluid dynamics with basic and history of numerical fluid dynamics, introduction of finite volume method using one-dimensional heat conduction equation, solution of two-dimensional heat conduction equation, solution of Navier-Stokes equation, fluid with heat transport, turbulent flow and turbulent model, Navier-Stokes solution by generalized coordinate system such as coordinate conversion, conversion of basic equation, program and example of calculation, application of abnormal problem and high speed solution of numerical fluid dynamics.

Fullerol ionic fluids

KAUST Repository

Fernandes, Nikhil; Dallas, Panagiotis; Rodriguez, Robert; Bourlinos, Athanasios B.; Georgakilas, Vasilios; Giannelis, Emmanuel P.

2010-01-01

®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding

Molecular mechanics and structure of the fluid-solid interface in simple fluids

Science.gov (United States)

Wang, Gerald J.; Hadjiconstantinou, Nicolas G.

2017-09-01

Near a fluid-solid interface, the fluid spatial density profile is highly nonuniform at the molecular scale. This nonuniformity can have profound effects on the dynamical behavior of the fluid and has been shown to play an especially important role when modeling a wide variety of nanoscale heat and momentum transfer phenomena. We use molecular-mechanics arguments and molecular-dynamics (MD) simulations to develop a better understanding of the structure of the first fluid layer directly adjacent to the solid in the layering regime, as delineated by a nondimensional number that compares the effects of wall-fluid interaction to thermal energy. Using asymptotic analysis of the Nernst-Planck equation, we show that features of the fluid density profile close to the wall, such as the areal density of the first layer ΣFL (defined as the number of atoms in this layer per unit of fluid-solid interfacial area), can be expressed as polynomial functions of the fluid average density ρave. This is found to be in agreement with MD simulations, which also show that the width of the first layer hFL is a linear function of the average density and only a weak function of the temperature T . These results can be combined to show that, for system average densities corresponding to a dense fluid (ρave≥0.7 ), the ratio C ≡ΣFLρavehFL, representing a density enhancement with respect to the bulk fluid, depends only weakly on temperature and is essentially independent of density. Further MD simulations suggest that the above results, nominally valid for large systems (solid in contact with semi-infinite fluid), also describe fluid-solid interfaces under considerable nanoconfinement, provided ρave is appropriately defined.

Fullerol ionic fluids

KAUST Repository

Fernandes, Nikhil

2010-01-01

We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine® (liquid-like) and the control (solid-like). © 2010 The Royal Society of Chemistry.

Fullerol ionic fluids

Science.gov (United States)

Fernandes, Nikhil; Dallas, Panagiotis; Rodriguez, Robert; Bourlinos, Athanasios B.; Georgakilas, Vasilios; Giannelis, Emmanuel P.

2010-09-01

We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine®). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol). In the fullerol fluid the ionic bonding significantly perturbs the thermal transitions and melting/crystallization behavior of the amine. In contrast, both the normalized heat of fusion and crystallization of the amine in the control are similar to those of the neat amine consistent with a physical mixture of the fullerols/amine with minimal interactions. In addition to differences in thermal behavior, the fullerol ionic fluid exhibits a complex viscoelastic behavior intermediate between the neat Jeffamine® (liquid-like) and the control (solid-like).

The Impact of Solid Surface Features on Fluid-Fluid Interface Configuration

Science.gov (United States)

Araujo, J. B.; Brusseau, M. L. L.

2017-12-01

Pore-scale fluid processes in geological media are critical for a broad range of applications such as radioactive waste disposal, carbon sequestration, soil moisture distribution, subsurface pollution, land stability, and oil and gas recovery. The continued improvement of high-resolution image acquisition and processing have provided a means to test the usefulness of theoretical models developed to simulate pore-scale fluid processes, through the direct quantification of interfaces. High-resolution synchrotron X-ray microtomography is used in combination with advanced visualization tools to characterize fluid distributions in natural geologic media. The studies revealed the presence of fluid-fluid interface associated with macroscopic features on the surfaces of the solids such as pits and crevices. These features and respective fluid interfaces, which are not included in current theoretical or computational models, may have a significant impact on accurate simulation and understanding of multi-phase flow, energy, heat and mass transfer processes.

Prevalence, extension and characteristics of fluid-fluid levels in bone and soft tissue tumors

Energy Technology Data Exchange (ETDEWEB)

Dyck, P. van; Venstermans, C.; Gielen, J.; Parizel, P.M. [University Hospital Antwerp, Department of Radiology, Edegem (Belgium); Vanhoenacker, F.M. [University Hospital Antwerp, Department of Radiology, Edegem (Belgium); AZ St-Maarten, Department of Radiology, Duffel/Mechelen (Belgium); Vogel, J. [Leiden University Medical Centre, Department of Orthopedics, Leiden (Netherlands); Kroon, H.M.; Bloem, J.L. [Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands); Schepper, A.M.A. de [University Hospital Antwerp, Department of Radiology, Edegem (Belgium); Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands)

2006-12-15

The purpose of this study was to determine the prevalence, extension and signal characteristics of fluid-fluid levels in a large series of 700 bone and 700 soft tissue tumors. Out of a multi-institutional database, MRI of 700 consecutive patients with a bone tumor and MRI of 700 consecutive patients with a soft tissue neoplasm were retrospectively reviewed for the presence of fluid-fluid levels. Extension (single, multiple and proportion of the lesion occupied by fluid-fluid levels) and signal characteristics on magnetic resonance imaging of fluid-fluid levels were determined. In all patients, pathologic correlation was available. Of 700 patients with a bone tumor, 19 (10 male and 9 female; mean age, 29 years) presented with a fluid-fluid level (prevalence 2.7%). Multiple fluid-fluid levels occupying at least one half of the total volume of the lesion were found in the majority of patients. Diagnoses included aneurysmal bone cyst (ten cases), fibrous dysplasia (two cases), osteoblastoma (one case), simple bone cyst (one case), telangiectatic osteosarcoma (one case), ''brown tumor'' (one case), chondroblastoma (one case) and giant cell tumor (two cases). Of 700 patients with a soft tissue tumor, 20 (9 males and 11 females; mean age, 34 years) presented with a fluid-fluid level (prevalence 2.9%). Multiple fluid-fluid levels occupying at least one half of the total volume of the lesion were found in the majority of patients. Diagnoses included cavernous hemangioma (12 cases), synovial sarcoma (3 cases), angiosarcoma (1 case), aneurysmal bone cyst of soft tissue (1 case), myxofibrosarcoma (1 case) and high-grade sarcoma ''not otherwise specified'' (2 cases). In our series, the largest reported in the literature to the best of our knowledge, the presence of fluid-fluid levels is a rare finding with a prevalence of 2.7 and 2.9% in bone and soft tissue tumors, respectively. Fluid-fluid levels remain a non-specific finding and can

Reduced abrasion drilling fluid

NARCIS (Netherlands)

2010-01-01

A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

Reduced abrasion drilling fluid

NARCIS (Netherlands)

2012-01-01

A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

Fluid dynamics transactions

CERN Document Server

Fiszdon, W

1965-01-01

Fluid Dynamics Transactions, Volume 2 compiles 46 papers on fluid dynamics, a subdiscipline of fluid mechanics that deals with fluid flow. The topics discussed in this book include developments in interference theory for aeronautical applications; diffusion from sources in a turbulent boundary layer; unsteady motion of a finite wing span in a compressible medium; and wall pressure covariance and comparison with experiment. The certain classes of non-stationary axially symmetric flows in magneto-gas-dynamics; description of the phenomenon of secondary flows in curved channels by means of co

Theoretical Fluid Dynamics

CERN Document Server

Shivamoggi, Bhimsen K

1998-01-01

"Although there are many texts and monographs on fluid dynamics, I do not know of any which is as comprehensive as the present book. It surveys nearly the entire field of classical fluid dynamics in an advanced, compact, and clear manner, and discusses the various conceptual and analytical models of fluid flow." - Foundations of Physics on the first edition. Theoretical Fluid Dynamics functions equally well as a graduate-level text and a professional reference. Steering a middle course between the empiricism of engineering and the abstractions of pure mathematics, the author focuses

Fluid sampling tool

Science.gov (United States)

Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

1999-05-25

A fluid sampling tool for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall.

Variable flexure-based fluid filter

Science.gov (United States)

Brown, Steve B.; Colston, Jr., Billy W.; Marshall, Graham; Wolcott, Duane

2007-03-13

An apparatus and method for filtering particles from a fluid comprises a fluid inlet, a fluid outlet, a variable size passage between the fluid inlet and the fluid outlet, and means for adjusting the size of the variable size passage for filtering the particles from the fluid. An inlet fluid flow stream is introduced to a fixture with a variable size passage. The size of the variable size passage is set so that the fluid passes through the variable size passage but the particles do not pass through the variable size passage.

Process fluid cooling system

International Nuclear Information System (INIS)

Farquhar, N.G.; Schwab, J.A.

1977-01-01

A system of heat exchangers is disclosed for cooling process fluids. The system is particularly applicable to cooling steam generator blowdown fluid in a nuclear plant prior to chemical purification of the fluid in which it minimizes the potential of boiling of the plant cooling water which cools the blowdown fluid

Space Station fluid management logistics

Science.gov (United States)

Dominick, Sam M.

1990-01-01

Viewgraphs and discussion on space station fluid management logistics are presented. Topics covered include: fluid management logistics - issues for Space Station Freedom evolution; current fluid logistics approach; evolution of Space Station Freedom fluid resupply; launch vehicle evolution; ELV logistics system approach; logistics carrier configuration; expendable fluid/propellant carrier description; fluid carrier design concept; logistics carrier orbital operations; carrier operations at space station; summary/status of orbital fluid transfer techniques; Soviet progress tanker system; and Soviet propellant resupply system observations.

Fluid dynamics

CERN Document Server

Bernard, Peter S

2015-01-01

This book presents a focused, readable account of the principal physical and mathematical ideas at the heart of fluid dynamics. Graduate students in engineering, applied math, and physics who are taking their first graduate course in fluids will find this book invaluable in providing the background in physics and mathematics necessary to pursue advanced study. The book includes a detailed derivation of the Navier-Stokes and energy equations, followed by many examples of their use in studying the dynamics of fluid flows. Modern tensor analysis is used to simplify the mathematical derivations, thus allowing a clearer view of the physics. Peter Bernard also covers the motivation behind many fundamental concepts such as Bernoulli's equation and the stream function. Many exercises are designed with a view toward using MATLAB or its equivalent to simplify and extend the analysis of fluid motion including developing flow simulations based on techniques described in the book.

Thermophysical properties of supercritical fluids and fluid mixtures

International Nuclear Information System (INIS)

Sengers, J.V.

1989-08-01

The purpose of the research is to extend the theory of critical phenomena in fluids and fluid mixtures to obtain scientifically based equations that include the crossover from the asymptotic singular behavior of the thermophysical properties close to the critical point to the regular behavior of these properties far away from the critical point

Fluid Creep and Over-resuscitation.

Science.gov (United States)

Saffle, Jeffrey R

2016-10-01

Fluid creep is the term applied to a burn resuscitation, which requires more fluid than predicted by standard formulas. Fluid creep is common today and is linked to several serious edema-related complications. Increased fluid requirements may accompany the appropriate resuscitation of massive injuries but dangerous fluid creep is also caused by overly permissive fluid infusion and the lack of colloid supplementation. Several strategies for recognizing and treating fluid creep are presented. Copyright © 2016 Elsevier Inc. All rights reserved.

Fluid sampling tool

Science.gov (United States)

Garcia, A.R.; Johnston, R.G.; Martinez, R.K.

1999-05-25

A fluid sampling tool is described for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall. 6 figs.

Working fluid selection for organic Rankine cycles - Impact of uncertainty of fluid properties

DEFF Research Database (Denmark)

Frutiger, Jerome; Andreasen, Jesper Graa; Liu, Wei

2016-01-01

of processmodels and constraints 2) selection of property models, i.e. Penge Robinson equation of state 3)screening of 1965 possible working fluid candidates including identification of optimal process parametersbased on Monte Carlo sampling 4) propagating uncertainty of fluid parameters to the ORC netpower output......This study presents a generic methodology to select working fluids for ORC (Organic Rankine Cycles)taking into account property uncertainties of the working fluids. A Monte Carlo procedure is described as a tool to propagate the influence of the input uncertainty of the fluid parameters on the ORC....... The net power outputs of all the feasible working fluids were ranked including their uncertainties. The method could propagate and quantify the input property uncertainty of the fluidproperty parameters to the ORC model, giving an additional dimension to the fluid selection process. In the given analysis...

Supercritical fluid reverse micelle separation

Science.gov (United States)

Fulton, J.L.; Smith, R.D.

1993-11-30

A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W[sub o] that determines the maximum size of the reverse micelles. The maximum ratio W[sub o] of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions. 27 figures.

Fluid and particle mechanics

CERN Document Server

Michell, S J

2013-01-01

Fluid and Particle Mechanics provides information pertinent to hydraulics or fluid mechanics. This book discusses the properties and behavior of liquids and gases in motion and at rest. Organized into nine chapters, this book begins with an overview of the science of fluid mechanics that is subdivided accordingly into two main branches, namely, fluid statics and fluid dynamics. This text then examines the flowmeter devices used for the measurement of flow of liquids and gases. Other chapters consider the principle of resistance in open channel flow, which is based on improper application of th

Fiber optic fluid detector

Science.gov (United States)

Angel, S.M.

1987-02-27

Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.

Hyperacid volcano-hydrothermal fluids from Copahue volcano, Argentina: Analogs for "subduction zone fluids"?

Science.gov (United States)

Varekamp, J. C.

2007-12-01

Hyperacid concentrated Chlorine-Sulfate brines occur in many young arc volcanoes, with pH values Copahue volcanic system (Argentina) suggest reservoir temperatures of 175-300 oC, whereas the surface fluids do not exceed local boiling temperatures. These fluids are generated at much lower P-T conditions than fluids associated with a dehydrating subducted sediment complex below arc volcanoes, but their fundamental chemical compositions may have similarities. Incompatible trace element, major element concentrations and Pb isotope compositions of the fluids were used to determine the most likely rock protoliths for these fluids. Mean rock- normalized trace element diagrams then indicate which elements are quantitatively extracted from the rocks and which are left behind or precipitated in secondary phases. Most LILE show flat rock-normalized patterns, indicating close to congruent dissolution, whereas Ta-Nb-Ti show strong depletions in the rock-normalized diagrams. These HFSE are either left behind in the altered rock protolith or were precipitated along the way up. The behavior of U and Th is almost identical, suggesting that in these low pH fluids with abundant ligands Th is just as easily transported as U, which is not the case in more dilute, neutral fluids. Most analyzed fluids have steeper LREE patterns than the rocks and have negative Eu anomalies similar to the rocks. Fluids that interacted with newly intruded magma e.g., during the 2000 eruption, have much less pronounced Eu anomalies, which was most likely caused by the preferential dissolution of plagioclase when newly intruded magma interacted with the acid fluids. The fluids show a strong positive correlation between Y and Cd (similar to MORB basalts, Yi et al., JGR, 2000), suggesting that Cd is mainly a rock-derived element that may not show chalcophilic behavior. The fluids are strongly enriched (relative to rock) in As, Zn and Pb, suggesting that these elements were carried with the volcanic gas phase

Differentiating benign from malignant bone tumors using fluid-fluid level features on magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Yu, Hong; Cui, Jian Ling; Cui, Sheng Jie; Sun, Ying Cal; Cui, Feng Zhen [Dept. of Radiology, The Third Hospital of Hebei Medical University, Hebei Province Biomechanical Key Laborary of Orthopedics, Shijiazhuang, Hebei (China)

2014-12-15

To analyze different fluid-fluid level features between benign and malignant bone tumors on magnetic resonance imaging (MRI). This study was approved by the hospital ethics committee. We retrospectively analyzed 47 patients diagnosed with benign (n = 29) or malignant (n = 18) bone tumors demonstrated by biopsy/surgical resection and who showed the intratumoral fluid-fluid level on pre-surgical MRI. The maximum length of the largest fluid-fluid level and the ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane were investigated for use in distinguishing benign from malignant tumors using the Mann-Whitney U-test and a receiver operating characteristic (ROC) analysis. Fluid-fluid level was categorized by quantity (multiple vs. single fluid-fluid level) and by T1-weighted image signal pattern (high/low, low/high, and undifferentiated), and the findings were compared between the benign and malignant groups using the chi2 test. The ratio of the maximum length of the largest fluid-fluid level to the maximum length of bone tumors in the sagittal plane that allowed statistically significant differentiation between benign and malignant bone tumors had an area under the ROC curve of 0.758 (95% confidence interval, 0.616-0.899). A cutoff value of 41.5% (higher value suggests a benign tumor) had sensitivity of 73% and specificity of 83%. The ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane may be useful to differentiate benign from malignant bone tumors.

Differentiating benign from malignant bone tumors using fluid-fluid level features on magnetic resonance imaging

International Nuclear Information System (INIS)

Yu, Hong; Cui, Jian Ling; Cui, Sheng Jie; Sun, Ying Cal; Cui, Feng Zhen

2014-01-01

To analyze different fluid-fluid level features between benign and malignant bone tumors on magnetic resonance imaging (MRI). This study was approved by the hospital ethics committee. We retrospectively analyzed 47 patients diagnosed with benign (n = 29) or malignant (n = 18) bone tumors demonstrated by biopsy/surgical resection and who showed the intratumoral fluid-fluid level on pre-surgical MRI. The maximum length of the largest fluid-fluid level and the ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane were investigated for use in distinguishing benign from malignant tumors using the Mann-Whitney U-test and a receiver operating characteristic (ROC) analysis. Fluid-fluid level was categorized by quantity (multiple vs. single fluid-fluid level) and by T1-weighted image signal pattern (high/low, low/high, and undifferentiated), and the findings were compared between the benign and malignant groups using the chi2 test. The ratio of the maximum length of the largest fluid-fluid level to the maximum length of bone tumors in the sagittal plane that allowed statistically significant differentiation between benign and malignant bone tumors had an area under the ROC curve of 0.758 (95% confidence interval, 0.616-0.899). A cutoff value of 41.5% (higher value suggests a benign tumor) had sensitivity of 73% and specificity of 83%. The ratio of the maximum length of the largest fluid-fluid level to the maximum length of a bone tumor in the sagittal plane may be useful to differentiate benign from malignant bone tumors.

Phoresis in fluids.

Science.gov (United States)

Brenner, Howard

2011-12-01

This paper presents a unified theory of phoretic phenomena in single-component fluids. Simple formulas are given for the phoretic velocities of small inert force-free non-Brownian particles migrating through otherwise quiescent single-component gases and liquids and animated by a gradient in the fluid's temperature (thermophoresis), pressure (barophoresis), density (pycnophoresis), or any combination thereof. The ansatz builds upon a recent paper [Phys. Rev. E 84, 046309 (2011)] concerned with slip of the fluid's mass velocity at solid surfaces--that is, with phenomena arising from violations of the classical no-slip fluid-mechanical boundary condition. Experimental and other data are cited in support of the phoretic model developed herein.

Plasmas and fluids

International Nuclear Information System (INIS)

Anon.

1986-01-01

Plasma and fluid physics includes the fields of fusion research and space investigation. This book discusses the most important advances in these areas over the past decade and recommends a stronger commitment to basic research in plasma and fluid physics. The book recommends that plasma and fluid physics be included in physics curriculums because of their increasing importance in energy and defense. The book also lists recent accomplishments in the fields of general plasma physics, fusion plasma confinement and heating, space and astrophysical plasmas, and fluid physics and lists research opportunities in these areas. A funding summary explains how research monies are allocated and suggests ways to improve their effectiveness

Schroedinger fluid

International Nuclear Information System (INIS)

Kan, K.K.

1983-01-01

The relationship of nuclear internal flow and collective inertia, the difference of this flow from that of a classical fluid, and the approach of this flow to rigid flow in independent-particle model rotation are elucidated by reviewing the theory of Schroedinger fluid and its implications for collective vibration and rotation. (author)

Intraoperative Fluids and Fluid Management for Ambulatory Dental Sedation and General Anesthesia.

Science.gov (United States)

Saraghi, Mana

2015-01-01

Intravenous fluids are administered in virtually every parenteral sedation and general anesthetic. The purpose of this article is to review the physiology of body-water distribution and fluid dynamics at the vascular endothelium, evaluation of fluid status, calculation of fluid requirements, and the clinical rationale for the use of various crystalloid and colloid solutions. In the setting of elective dental outpatient procedures with minor blood loss, isotonic balanced crystalloid solutions are the fluids of choice. Colloids, on the other hand, have no use in outpatient sedation or general anesthesia for dental or minor oral surgery procedures but may have several desirable properties in long and invasive maxillofacial surgical procedures where advanced hemodynamic monitoring may assess the adequacy of intravascular volume.

Fiber optic fluid detector

Science.gov (United States)

Angel, S. Michael

1989-01-01

Particular gases or liquids are detected with a fiber optic element (11, 11a to 11j) having a cladding or coating of a material (23, 23a to 23j) which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector (24, 24a to 24j) may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses.

Working fluid selection for organic Rankine cycles - Impact of uncertainty of fluid properties

DEFF Research Database (Denmark)

Frutiger, Jerome; Andreasen, Jesper Graa; Liu, Wei

2016-01-01

This study presents a generic methodology to select working fluids for ORC (Organic Rankine Cycles)taking into account property uncertainties of the working fluids. A Monte Carlo procedure is described as a tool to propagate the influence of the input uncertainty of the fluid parameters on the ORC...... modeloutput, and provides the 95%-confidence interval of the net power output with respect to the fluid property uncertainties. The methodology has been applied to a molecular design problem for an ORCusing a low-temperature heat source and consisted of the following four parts: 1) formulation...... of processmodels and constraints 2) selection of property models, i.e. Penge Robinson equation of state 3)screening of 1965 possible working fluid candidates including identification of optimal process parametersbased on Monte Carlo sampling 4) propagating uncertainty of fluid parameters to the ORC netpower output...

Explosive Evaporating Phenomena of Cryogenic Fluids by Direct Contacting Normal Temperature Fluids

Directory of Open Access Journals (Sweden)

T Watanabe

2016-09-01

Full Text Available Cryogenic fluids have characteristics such as thermal stratification and flashing by pressure release in storage vessel. The mixture of the extreme low temperature fluid and the normal temperature fluid becomes the cause which causes pressure vessel and piping system crush due to explosive boiling and rapid freezing. In recent years in Japan, the demand of cryogenic fluids like a LH2, LNG is increasing because of the advance of fuel cell device technology, hydrogen of engine, and stream of consciousness for environmental agreement. These fuel liquids are cryogenic fluids. On the other hand, as for fisheries as well, the use of a source of energy that environment load is small has been being a pressing need. And, the need of the ice is high, as before, for keeping freshness of marine products in fisheries. Therefore, we carried out the experiments related to promotion of evaporating cryogenic fluids and generation of ice, in the contact directly of the water and liquid nitrogen. From the results of visualization, phenomena of explosive evaporating and ice forming were observed by using video camera.

Thermodynamics of Fluid Polyamorphism

Directory of Open Access Journals (Sweden)

Mikhail A. Anisimov

2018-01-01

Full Text Available Fluid polyamorphism is the existence of different condensed amorphous states in a single-component fluid. It is either found or predicted, usually at extreme conditions, for a broad group of very different substances, including helium, carbon, silicon, phosphorous, sulfur, tellurium, cerium, hydrogen, and tin tetraiodide. This phenomenon is also hypothesized for metastable and deeply supercooled water, presumably located a few degrees below the experimental limit of homogeneous ice formation. We present a generic phenomenological approach to describe polyamorphism in a single-component fluid, which is completely independent of the molecular origin of the phenomenon. We show that fluid polyamorphism may occur either in the presence or in the absence of fluid phase separation depending on the symmetry of the order parameter. In the latter case, it is associated with a second-order transition, such as in liquid helium or liquid sulfur. To specify the phenomenology, we consider a fluid with thermodynamic equilibrium between two distinct interconvertible states or molecular structures. A fundamental signature of this concept is the identification of the equilibrium fraction of molecules involved in each of these alternative states. However, the existence of the alternative structures may result in polyamorphic fluid phase separation only if mixing of these structures is not ideal. The two-state thermodynamics unifies all the debated scenarios of fluid polyamorphism in different areas of condensed-matter physics, with or without phase separation, and even goes beyond the phenomenon of polyamorphism by generically describing the anomalous properties of fluids exhibiting interconversion of alternative molecular states.

Cerebrospinal fluid culture

Science.gov (United States)

... Alternative Names Culture - CSF; Spinal fluid culture; CSF culture Images Pneumococci organism References Karcher DS, McPherson RA. Cerebrospinal, synovial, serous body fluids, and alternative specimens. In: McPherson RA, Pincus ...

Fluid, solid and fluid-structure interaction simulations on patient-based abdominal aortic aneurysm models.

Science.gov (United States)

Kelly, Sinead; O'Rourke, Malachy

2012-04-01

This article describes the use of fluid, solid and fluid-structure interaction simulations on three patient-based abdominal aortic aneurysm geometries. All simulations were carried out using OpenFOAM, which uses the finite volume method to solve both fluid and solid equations. Initially a fluid-only simulation was carried out on a single patient-based geometry and results from this simulation were compared with experimental results. There was good qualitative and quantitative agreement between the experimental and numerical results, suggesting that OpenFOAM is capable of predicting the main features of unsteady flow through a complex patient-based abdominal aortic aneurysm geometry. The intraluminal thrombus and arterial wall were then included, and solid stress and fluid-structure interaction simulations were performed on this, and two other patient-based abdominal aortic aneurysm geometries. It was found that the solid stress simulations resulted in an under-estimation of the maximum stress by up to 5.9% when compared with the fluid-structure interaction simulations. In the fluid-structure interaction simulations, flow induced pressure within the aneurysm was found to be up to 4.8% higher than the value of peak systolic pressure imposed in the solid stress simulations, which is likely to be the cause of the variation in the stress results. In comparing the results from the initial fluid-only simulation with results from the fluid-structure interaction simulation on the same patient, it was found that wall shear stress values varied by up to 35% between the two simulation methods. It was concluded that solid stress simulations are adequate to predict the maximum stress in an aneurysm wall, while fluid-structure interaction simulations should be performed if accurate prediction of the fluid wall shear stress is necessary. Therefore, the decision to perform fluid-structure interaction simulations should be based on the particular variables of interest in a given

Effect of pre-donation fluid intake on fluid shift from interstitial to intravascular compartment in blood donors.

Science.gov (United States)

Deepika, Chenna; Murugesan, Mohandoss; Shastry, Shamee

2018-02-01

Fluid shifts from interstitial to intravascular space during blood donation helps in compensating the lost blood volume. We aimed to determine the volume of fluid shift following donation in donors with and without pre-donation fluid intake. We studied the fluid shift in 325 blood donors prospectively. Donors were divided in groups- with no fluid intake (GI) and either water (GII) or oral rehydrating fluids (GIII) before donation. Fluid shift following donation was calculated based on the difference between the pre and post donation blood volume. The influence of oral fluid intake, age, gender and body mass index (BMI) on volume of fluid shift was analyzed. The fluid shift was significant between donors without fluids (GI: 127 ± 81 ml) and donors with fluid intake (GII & III: 96 ± 45 ml) (p donation. As per our observation, the oral fluids before donation might not contribute to increase in fluid shift in blood donors after donation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heating production fluids in a wellbore

Science.gov (United States)

Orrego, Yamila; Jankowski, Todd A.

2016-07-12

A method for heating a production fluid in a wellbore. The method can include heating, using a packer fluid, a working fluid flowing through a first medium disposed in a first section of the wellbore, where the first medium transfers heat from the packer fluid to the working fluid. The method can also include circulating the working fluid into a second section of the wellbore through a second medium, where the second medium transfers heat from the working fluid to the production fluid. The method can further include returning the working fluid to the first section of the wellbore through the first medium.

Microgravity Fluids for Biology, Workshop

Science.gov (United States)

Griffin, DeVon; Kohl, Fred; Massa, Gioia D.; Motil, Brian; Parsons-Wingerter, Patricia; Quincy, Charles; Sato, Kevin; Singh, Bhim; Smith, Jeffrey D.; Wheeler, Raymond M.

2013-01-01

Microgravity Fluids for Biology represents an intersection of biology and fluid physics that present exciting research challenges to the Space Life and Physical Sciences Division. Solving and managing the transport processes and fluid mechanics in physiological and biological systems and processes are essential for future space exploration and colonization of space by humans. Adequate understanding of the underlying fluid physics and transport mechanisms will provide new, necessary insights and technologies for analyzing and designing biological systems critical to NASAs mission. To enable this mission, the fluid physics discipline needs to work to enhance the understanding of the influence of gravity on the scales and types of fluids (i.e., non-Newtonian) important to biology and life sciences. In turn, biomimetic, bio-inspired and synthetic biology applications based on physiology and biology can enrich the fluid mechanics and transport phenomena capabilities of the microgravity fluid physics community.

Fluid Statics and Archimedes

Indian Academy of Sciences (India)

librium of a vertical slice fluid (Figure Id) of height H and again using the fact .... same fluid having the same shape and same volume as the body. This fluid volume .... example, can be caused by the heating of air near the ground by the sun ...

Agarwood Waste as A New Fluid Loss Control Agent in Water-based Drilling Fluid

Directory of Open Access Journals (Sweden)

Azlinda Azizi

2013-10-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Agarwood has been used widely in various ways, including traditional medicine and art. The usage of agarwood has grown broader in modern times include in therapeutic medicines and perfumery. In this paper the agarwood waste has been explored to be used as a fluid loss control agent to control fluid loss without affecting the drilling fluid rheological properties which are density, pH, viscosity, yield point and gel strength. Agarwood waste was used as an additive in the drilling fluid system due to its unique characteristic. Rheological and filtration measurements were performed on the formulated water-based drilling fluid. Formulations of a base solution of fresh water, sodium hydroxide, bentonite, barite, and xanthan gum were presented. The performance of the agarwood waste as the fluid loss control agent was compared with based fluid formulation and water-based drilling fluid with treating with conventional fluid loss control agent (starch. The filtrate volume of drilling fluid with agarwood waste was about 13 ml while for drilling fluid with conventional fluid loss control agent, starch gave 12 ml of filtrate volume after undergoing filtration test by using LPLT filter press. The performance of drilling fluid with agarwood was efficient as drilling fluid with starch. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso

Extension of Generalized Fluid System Simulation Program's Fluid Property Database

Science.gov (United States)

Patel, Kishan

2011-01-01

This internship focused on the development of additional capabilities for the General Fluid Systems Simulation Program (GFSSP). GFSSP is a thermo-fluid code used to evaluate system performance by a finite volume-based network analysis method. The program was developed primarily to analyze the complex internal flow of propulsion systems and is capable of solving many problems related to thermodynamics and fluid mechanics. GFSSP is integrated with thermodynamic programs that provide fluid properties for sub-cooled, superheated, and saturation states. For fluids that are not included in the thermodynamic property program, look-up property tables can be provided. The look-up property tables of the current release version can only handle sub-cooled and superheated states. The primary purpose of the internship was to extend the look-up tables to handle saturated states. This involves a) generation of a property table using REFPROP, a thermodynamic property program that is widely used, and b) modifications of the Fortran source code to read in an additional property table containing saturation data for both saturated liquid and saturated vapor states. Also, a method was implemented to calculate the thermodynamic properties of user-fluids within the saturation region, given values of pressure and enthalpy. These additions required new code to be written, and older code had to be adjusted to accommodate the new capabilities. Ultimately, the changes will lead to the incorporation of this new capability in future versions of GFSSP. This paper describes the development and validation of the new capability.

Synovial Fluid Analysis

Science.gov (United States)

... Plasma Free Metanephrines Platelet Count Platelet Function Tests Pleural Fluid Analysis PML-RARA Porphyrin Tests Potassium Prealbumin ... is being tested? Synovial fluid is a thick liquid that acts as a lubricant for the body's ...

Fluid structure interaction due to fluid communications between fluid volumes. Application to seismic behaviour of F.B.R. vessels

International Nuclear Information System (INIS)

Durandet, E.; Gibert, R.J.; Gantenbein, F.

1988-01-01

The internal structures of a pool-type breeder reactor are mainly axisymmetric shells separated by fluid volumes which are connected one to another by small communications. Unfortunately, the communications destroy the axisymmetry of the problem and a correct modelisation by finite element method generally need a lot of small elements compared to the size of the standard mesh of the fluid volumes. To overcome these difficulties, an equivalent axisymmetric element based on a local tridimensional solution in the vicinity of the fluid communication is defined and will be described in the paper. This special fluid element is characterized by an equivalent length and annular cross-section. The second part of the paper is devoted to the application to an horizontal seismic calculation of breeder reactor

Gastric fluid versus amniotic fluid analysis for the identification of intra-amniotic infection due to Ureaplasma species.

Science.gov (United States)

Kim, Sun Min; Romero, Roberto; Lee, JoonHo; Chaemsaithong, Piya; Docheva, Nikolina; Yoon, Bo Hyun

2016-01-01

Early neonatal sepsis is often due to intra-amniotic infection. The stomach of the neonate contains fluid swallowed before and during delivery. The presence of bacteria as well as neutrophils detected by culture or Gram stain of the gastric fluid during the first day of life is suggestive of exposure to bacteria or inflammation. We undertook this study to determine the relationship between gastric fluid analysis and amniotic fluid obtained by transabdominal amniocentesis in the detection of Ureaplasma species, the most frequent microorganisms responsible for intra-amniotic infection. The study population consisted of 100 singleton pregnant women who delivered preterm neonates (Ureaplasma species was performed. Intra-amniotic inflammation was defined as an elevated amniotic fluid matrix metalloproteinase-8 concentration (>23 ng/mL). (1) Ureaplasma species were detected by culture or PCR in 18% (18/100) of amniotic fluid samples and in 5% (5/100) of gastric fluid samples; (2) among the amniotic fluid cases positive for Ureaplasma species, these microorganisms were identified in 27.8% (5/18) of gastric fluid samples; (3) none of the cases negative for Ureaplasma species in the amniotic fluid were found to be positive for these microorganisms in the gastric fluid; (4) patients with amniotic fluid positive for Ureaplasma species but with gastric fluid negative for these microorganisms had a significantly higher rate of intra-amniotic inflammation, acute histologic chorioamnionitis, and neonatal death than those with both amniotic fluid and gastric fluid negative for Ureaplasma species; and (5) no significant differences were observed in the rate of intra-amniotic inflammation, acute histologic chorioamnionitis, and neonatal death between patients with amniotic fluid positive for Ureaplasma species but with gastric fluid negative for these microorganisms and those with both amniotic fluid and gastric fluid positive for Ureaplasma species. Gastric fluid analysis has 100

Improved Fluid Perturbation Theory: Equation of state for Fluid Xenon

OpenAIRE

Li, Qiong; Liu, Hai-Feng; Zhang, Gong-Mu; Zhao, Yan-Hong; Tian, Ming-Feng; Song, Hai-Feng

2016-01-01

The traditional fluid perturbation theory is improved by taking electronic excitations and ionizations into account, in the framework of average ion spheres. It is applied to calculate the equation of state for fluid Xenon, which turns out in good agreement with the available shock data.

Numerical study of shear thickening fluid with discrete particles embedded in a base fluid

Directory of Open Access Journals (Sweden)

W Zhu

2016-09-01

Full Text Available The Shear Thickening Fluid (STF is a dilatant material, which displays non-Newtonian characteristics in its unique ability to transit from a low viscosity fluid to a high viscosity fluid. The research performed investigates the STF behavior by modeling and simulation of the interaction between the base flow and embedded rigid particles when subjected to shear stress. The model considered the Lagrangian description of the rigid particles and the Eulerian description of fluid flow. The numerical analysis investigated key parameters such as applied flow acceleration, particle distribution and arrangement, volume concentration of particles, particle size, shape and their behavior in a Newtonian and non-Newtonian fluid base. The fluid-particle interaction model showed that the arrangement, size, shape and volume concentration of the particles had a significant effect on the behavior of the STF. Although non-conclusive, the addition of particles in non-Newtonian fluids showed a promising trend of improved shear thickening effects at high shear strain rates.

Simplified Aeroelastic Model for Fluid Structure Interaction between Microcantilever Sensors and Fluid Surroundings.

Directory of Open Access Journals (Sweden)

Fei Wang

Full Text Available Fluid-structural coupling occurs when microcantilever sensors vibrate in a fluid. Due to the complexity of the mechanical characteristics of microcantilevers and lack of high-precision microscopic mechanical testing instruments, effective methods for studying the fluid-structural coupling of microcantilevers are lacking, especially for non-rectangular microcantilevers. Here, we report fluid-structure interactions (FSI of the cable-membrane structure via a macroscopic study. The simplified aeroelastic model was introduced into the microscopic field to establish a fluid-structure coupling vibration model for microcantilever sensors. We used the finite element method to solve the coupled FSI system. Based on the simplified aeroelastic model, simulation analysis of the effects of the air environment on the vibration of the commonly used rectangular microcantilever was also performed. The obtained results are consistent with the literature. The proposed model can also be applied to the auxiliary design of rectangular and non-rectangular sensors used in fluid environments.

Electrorheological fluids and methods

Science.gov (United States)

Green, Peter F.; McIntyre, Ernest C.

2015-06-02

Electrorheological fluids and methods include changes in liquid-like materials that can flow like milk and subsequently form solid-like structures under applied electric fields; e.g., about 1 kV/mm. Such fluids can be used in various ways as smart suspensions, including uses in automotive, defense, and civil engineering applications. Electrorheological fluids and methods include one or more polar molecule substituted polyhedral silsesquioxanes (e.g., sulfonated polyhedral silsesquioxanes) and one or more oils (e.g., silicone oil), where the fluid can be subjected to an electric field.

Rigid Body Sampling and Individual Time Stepping for Rigid-Fluid Coupling of Fluid Simulation

Directory of Open Access Journals (Sweden)

Xiaokun Wang

2017-01-01

Full Text Available In this paper, we propose an efficient and simple rigid-fluid coupling scheme with scientific programming algorithms for particle-based fluid simulation and three-dimensional visualization. Our approach samples the surface of rigid bodies with boundary particles that interact with fluids. It contains two procedures, that is, surface sampling and sampling relaxation, which insures uniform distribution of particles with less iterations. Furthermore, we present a rigid-fluid coupling scheme integrating individual time stepping to rigid-fluid coupling, which gains an obvious speedup compared to previous method. The experimental results demonstrate the effectiveness of our approach.

Thermal Fluid Engineering

International Nuclear Information System (INIS)

Jang, Byeong Ju

1984-01-01

This book is made up of 5 chapters. They are fluid mechanics, fluid machines, Industrial thermodynamics, steam boiler and steam turbine. It introduces hydrostatics, basic theory of fluid movement and law of momentum. It also deals with centrifugal pump, axial flow pump, general hydraulic turbine, and all phenomena happening in the pump. It covers the law of thermodynamics, perfect gas, properties of steam, and flow of gas and steam and water tube boiler. Lastly it explains basic format, theory, loss and performance as well as principle part of steam turbine.

Fluid jet electric discharge source

Science.gov (United States)

Bender, Howard A [Ripon, CA

2006-04-25

A fluid jet or filament source and a pair of coaxial high voltage electrodes, in combination, comprise an electrical discharge system to produce radiation and, in particular, EUV radiation. The fluid jet source is composed of at least two serially connected reservoirs, a first reservoir into which a fluid, that can be either a liquid or a gas, can be fed at some pressure higher than atmospheric and a second reservoir maintained at a lower pressure than the first. The fluid is allowed to expand through an aperture into a high vacuum region between a pair of coaxial electrodes. This second expansion produces a narrow well-directed fluid jet whose size is dependent on the size and configuration of the apertures and the pressure used in the reservoir. At some time during the flow of the fluid filament, a high voltage pulse is applied to the electrodes to excite the fluid to form a plasma which provides the desired radiation; the wavelength of the radiation being determined by the composition of the fluid.

Ecotoxicological testing of performance fluids

International Nuclear Information System (INIS)

Kallqvist, T.

1990-05-01

The report deals with a project comprising the testing of drilling fluids concerning ecotoxicology, biological degradation, and toxicity. Two types of drilling fluids were tested for toxic effects on marine algae and biological degradability. A fluid based on mineral oil was readily degradable (98% DOC removal in 28 days) while an ether based oil degraded more slowly (56% DOC removal in 28 days). The toxicity of both fluids was tested after emulsification of the oils in water and separating the oil and water phase after equilibration. The EC 50 values obtained with this approach were 8.15 g/l for the oil based fluid and 116 g/l for the ether fluid. 9 figs., 8 tabs

Peritoneal fluid culture

Science.gov (United States)

Culture - peritoneal fluid ... sent to the laboratory for Gram stain and culture. The sample is checked to see if bacteria ... The peritoneal fluid culture may be negative, even if you have ... diagnosis of peritonitis is based on other factors, in addition ...

Time Independent Fluids

Science.gov (United States)

Collyer, A. A.

1973-01-01

Discusses theories underlying Newtonian and non-Newtonian fluids by explaining flow curves exhibited by plastic, shear-thining, and shear-thickening fluids and Bingham plastic materials. Indicates that the exact mechanism governing shear-thickening behaviors is a problem of further study. (CC)

Editorial Special Issue on Fluid Mechanics and Fluid Power (FMFP ...

Indian Academy of Sciences (India)

a shark is more efficient than a propeller; the notoriously complicated and nonlinear Navier–. Stokes equations governing fluid motion provide fertile ground for research to both applied and pure mathematicians. There is the phenomenon of turbulence in fluid flows. A statement in 1932, attributed to Horace Lamb, author of ...

Acoustic Velocity and Attenuation in Magnetorhelogical fluids based on an effective density fluid model

Directory of Open Access Journals (Sweden)

Shen Min

2016-01-01

Full Text Available Magnetrohelogical fluids (MRFs represent a class of smart materials whose rheological properties change in response to the magnetic field, which resulting in the drastic change of the acoustic impedance. This paper presents an acoustic propagation model that approximates a fluid-saturated porous medium as a fluid with a bulk modulus and effective density (EDFM to study the acoustic propagation in the MRF materials under magnetic field. The effective density fluid model derived from the Biot’s theory. Some minor changes to the theory had to be applied, modeling both fluid-like and solid-like state of the MRF material. The attenuation and velocity variation of the MRF are numerical calculated. The calculated results show that for the MRF material the attenuation and velocity predicted with this effective density fluid model are close agreement with the previous predictions by Biot’s theory. We demonstrate that for the MRF material acoustic prediction the effective density fluid model is an accurate alternative to full Biot’s theory and is much simpler to implement.

Fluid Behavior and Fluid-Solid Interactions in Nanoporous Media

Science.gov (United States)

Xu, H.

2015-12-01

Although shale oil/gas production in the US has increased exponentially, the low energy recovery is a daunting problem needed to be solved for its sustainability and continued growth, especially in light of the recent oil/gas price decline. This is apparently related to the small porosity (a few to a few hundred nm) and low permeability (10-16-10-20 m2) of tight shale formations. The fundamental question lies in the anomalous behavior of fluids in nanopores due to confinement effects, which, however, remains poorly understood. In this study, we combined experimental characterization and observations, particularly using small-angle neutron scattering (SANS), with pore-scale modeling using lattice Boltzmann method (LBM), to examine the fluid behavior and fluid-solid interactions in nanopores at reservoir conditions. Experimentally, we characterized the compositions and microstructures of a shale sample from Wolfcamp, Texas, using a variety of analytical techniques. Our analyses reveal that the shale sample is made of organic-matter (OM)-lean and OM-rich layers that exhibit different chemical and mineral compositions, and microstructural characteristics. Using the hydrostatic pressure system and gas-mixing setup we developed, in-situ SANS measurements were conducted at pressures up to 20 kpsi on shale samples imbibed with water or water-methane solutions. The obtained results indicate that capillary effect plays a significant role in fluid-nanopore interactions and the associated changes in nanopore structures vary with pore size and pressure. Computationally, we performed LBM modeling to simulate the flow behavior of methane in kerogen nanoporous structure. The correction factor, which is the ratio of apparent permeability to intrinsic permeability, was calculated. Our results show that the correction factor is always greater than one (non-continuum/non-Darcy effects) and increases with decreasing nanopore size, intrinsic permeability and pressure. Hence, the

Heat transfer fluids containing nanoparticles

Science.gov (United States)

Singh, Dileep; Routbort, Jules; Routbort, A.J.; Yu, Wenhua; Timofeeva, Elena; Smith, David S.; France, David M.

2016-05-17

A nanofluid of a base heat transfer fluid and a plurality of ceramic nanoparticles suspended throughout the base heat transfer fluid applicable to commercial and industrial heat transfer applications. The nanofluid is stable, non-reactive and exhibits enhanced heat transfer properties relative to the base heat transfer fluid, with only minimal increases in pumping power required relative to the base heat transfer fluid. In a particular embodiment, the plurality of ceramic nanoparticles comprise silicon carbide and the base heat transfer fluid comprises water and water and ethylene glycol mixtures.

Assessment of magnetic fluid stability in non-homogeneous magnetic field of a single-tooth magnetic fluid sealer

Energy Technology Data Exchange (ETDEWEB)

Arefyev, I.M.; Demidenko, O.V.; Saikin, M.S.

2017-06-01

A special experimental stand has been developed and made to test magnetic fluid. It represents a single-tooth magnetic fluid sealer. The type of dependence of the pressure differential on magnetic fluid sealer operation time is used as a criterion to determine magnetic fluid stability and magnetic fluid sealer service life under such conditions. The siloxane-based magnetic fluid was used as the test sample. The colloidal stability as well as stability of the synthesized magnetic fluid in magnetic fields in static mode were determined. It has been found that the obtained magnetic fluid is stable in static mode and, consequently, can be used to conduct necessary tests on stand. Short-term and life tests on stand have shown that MF remains stable and efficient for at least 360 days of continuous utilization. - Highlights: • An experimental single-tooth magnetic fluid sealer has been developed and made. • The magnetic fluid based on siloxane liquid was used as the test sample. • Short-term and life tests of the magnetic fluid were conducted. • The magnetic fluid stability was determined by necessary tests on stand.

Tumor interstitial fluid

DEFF Research Database (Denmark)

Gromov, Pavel; Gromova, Irina; Olsen, Charlotta J.

2013-01-01

Tumor interstitial fluid (TIF) is a proximal fluid that, in addition to the set of blood soluble phase-borne proteins, holds a subset of aberrantly externalized components, mainly proteins, released by tumor cells and tumor microenvironment through various mechanisms, which include classical...

Fluid mechanics. Vol. 2

International Nuclear Information System (INIS)

Truckenbrodt, E.

1980-01-01

The second volume contains the chapter 4 to 6. Whereas chapter 1 deals with the introduction into the mechanics of fluids and chapter 2 with the fundamental laws of fluid and thermal fluid dynamics, in chapter 3 elementary flow phenomena in fluids with constant density are treated. Chapter 4 directly continues chapter 3 and describes elementary flow phenomena in fluids with varying density. Fluid statics again is treated as a special case. If compared with the first edition the treatment of unsteady laminar flow and of pipe flow for a fluid with varying density were subject to a substantial extension. In chapter 5 rotation-free and rotating potential flows are presented together. By this means it is achieved to explain the behaviour of the multidimensional fictionless flow in closed form. A subchapter describes some related problems of potential theory like the flow along a free streamline and seepage flow through a porous medium. The boundary layer flows in chapter 6 are concerned with the flow and temperature boundary layer in laminar and turbulent flows at a fired wall. In it differential and integral methods are applied of subchapter reports on boundary layer flows without a fixed boundary, occurring e.g. in an open jet and in a wake flow. The problems of intermittence and of the Coanda effect are briefly mentioned. (orig./MH)

FRACTURING FLUID CHARACTERIZATION FACILITY

Energy Technology Data Exchange (ETDEWEB)

Subhash Shah

2000-08-01

Hydraulic fracturing technology has been successfully applied for well stimulation of low and high permeability reservoirs for numerous years. Treatment optimization and improved economics have always been the key to the success and it is more so when the reservoirs under consideration are marginal. Fluids are widely used for the stimulation of wells. The Fracturing Fluid Characterization Facility (FFCF) has been established to provide the accurate prediction of the behavior of complex fracturing fluids under downhole conditions. The primary focus of the facility is to provide valuable insight into the various mechanisms that govern the flow of fracturing fluids and slurries through hydraulically created fractures. During the time between September 30, 1992, and March 31, 2000, the research efforts were devoted to the areas of fluid rheology, proppant transport, proppant flowback, dynamic fluid loss, perforation pressure losses, and frictional pressure losses. In this regard, a unique above-the-ground fracture simulator was designed and constructed at the FFCF, labeled ''The High Pressure Simulator'' (HPS). The FFCF is now available to industry for characterizing and understanding the behavior of complex fluid systems. To better reflect and encompass the broad spectrum of the petroleum industry, the FFCF now operates under a new name of ''The Well Construction Technology Center'' (WCTC). This report documents the summary of the activities performed during 1992-2000 at the FFCF.

Total phosphorus recovery in flowback fluids after gelled hydrocarbon fracturing fluid treatments

Energy Technology Data Exchange (ETDEWEB)

Fyten, G.; Houle, P.; Taylor, R.S. [Halliburton Energy Services, Calgary, AB (Canada); Stemler, P.S. [Petro-Canada Oil and Gas Inc., Calgary, AB (Canada); Lemieux, A. [Omnicon Consultants Inc., Calgary, AB (Canada)

2006-07-01

Carbon dioxide miscible hydrocarbon fracturing fluids are used in unconventional gas reservoirs such as tight gas, shale gas, and coalbed methane. These fracturing fluids address phase trapping concerns by using oil-based fracturing fluid technology for use in reservoirs that are water sensitive. This paper addressed the problem of refinery tower fouling caused by volatile phosphorous components found in phosphate ester oil gellants. In order to address costly unplanned refinery shutdowns, a maximum 0.5 ppm volatile phosphorus in crude specification has been proposed. However, this specification is based on average concentrations of phosphorus added to the oil to gel it. The specification also falsely assumes that the oil is phosphorus free to begin with. The authors noted that refinery tower fouling is actually the result of total phosphorus throughput rather than peak concentrations at any one point. This paper focused on the total phosphorus recovery in addition to peak concentrations. It also examined what percentage of the total recovered phosphorus is in fact volatile, since this is the material that plugs the trays. The total per cent recovery of phosphorus originally added as phosphorus based gellant was examined along with the total percent recovery of volatile phosphorus as a function of total phosphorus. The phosphorus concentrations in both new and reused fracturing fluids before addition of gellants was also examined along with the potential explanations for phosphorus concentrations higher than those originally added. It was shown that the first 50 per cent of a hydraulic fracturing fluid flowback can result in recovery of greater than or less than the amount of phosphorus added to that portion of the fracturing fluid. The initial high concentrations of total and volatile phosphorus are greater than the phosphorus concentrations inherent in the system. Therefore, as flowback continues, there would be a rapid decline in the concentration of phosphorus

Instrumentation, measurements, and experiments in fluids

CERN Document Server

Rathakrishnan, E

2007-01-01

NEED AND OBJECTIVE OF EXPERIMENTAL STUDY Some Fluid Mechanics MeasurementsMeasurement SystemsSome of the Important Quantities Associated with FluidFlow MeasurementsFUNDAMENTALS OF FLUID MECHANICSProperties of FluidsThermodynamic PropertiesSurface TensionAnalysis of Fluid FlowBasic and Subsidiary Laws for Continuous MediaKinematics of Fluid FlowStreamlinesPotential FlowViscous FlowsGas DynamicsWIND TUNNELSLow-Speed Wind TunnelsPower Losses in a Wind TunnelHigh-Speed Wind TunnelsHypersonic TunnelsInstrume

Controlled capillary assembly of magnetic Janus Particles at fluid-fluid interfaces

NARCIS (Netherlands)

Xie, Q.; Davies, G.B.; Harting, J.D.R.

2016-01-01

Capillary interactions can be used to direct assembly of particles adsorbed at fluid-fluid interfaces. Precisely controlling the magnitude and direction of capillary interactions to assemble particles into favoured structures for materials science purposes is desirable but challenging. In this

Magnetic power piston fluid compressor

Science.gov (United States)

Gasser, Max G. (Inventor)

1994-01-01

A compressor with no moving parts in the traditional sense having a housing having an inlet end allowing a low pressure fluid to enter and an outlet end allowing a high pressure fluid to exit is described. Within the compressor housing is at least one compression stage to increase the pressure of the fluid within the housing. The compression stage has a quantity of magnetic powder within the housing, is supported by a screen that allows passage of the fluid, and a coil for selectively providing a magnetic field across the magnetic powder such that when the magnetic field is not present the individual particles of the powder are separated allowing the fluid to flow through the powder and when the magnetic field is present the individual particles of the powder pack together causing the powder mass to expand preventing the fluid from flowing through the powder and causing a pressure pulse to compress the fluid.

Noncommutative geometry and fluid dynamics

International Nuclear Information System (INIS)

Das, Praloy; Ghosh, Subir

2016-01-01

In the present paper we have developed a Non-Commutative (NC) generalization of perfect fluid model from first principles, in a Hamiltonian framework. The noncommutativity is introduced at the Lagrangian (particle) coordinate space brackets and the induced NC fluid bracket algebra for the Eulerian (fluid) field variables is derived. Together with a Hamiltonian this NC algebra generates the generalized fluid dynamics that satisfies exact local conservation laws for mass and energy, thereby maintaining mass and energy conservation. However, nontrivial NC correction terms appear in the charge and energy fluxes. Other non-relativistic spacetime symmetries of the NC fluid are also discussed in detail. This constitutes the study of kinematics and dynamics of NC fluid. In the second part we construct an extension of the Friedmann-Robertson-Walker (FRW) cosmological model based on the NC fluid dynamics presented here. We outline the way in which NC effects generate cosmological perturbations bringing about anisotropy and inhomogeneity in the model. We also derive a NC extended Friedmann equation. (orig.)

Noncommutative geometry and fluid dynamics

Energy Technology Data Exchange (ETDEWEB)

Das, Praloy; Ghosh, Subir [Indian Statistical Institute, Physics and Applied Mathematics Unit, Kolkata (India)

2016-11-15

In the present paper we have developed a Non-Commutative (NC) generalization of perfect fluid model from first principles, in a Hamiltonian framework. The noncommutativity is introduced at the Lagrangian (particle) coordinate space brackets and the induced NC fluid bracket algebra for the Eulerian (fluid) field variables is derived. Together with a Hamiltonian this NC algebra generates the generalized fluid dynamics that satisfies exact local conservation laws for mass and energy, thereby maintaining mass and energy conservation. However, nontrivial NC correction terms appear in the charge and energy fluxes. Other non-relativistic spacetime symmetries of the NC fluid are also discussed in detail. This constitutes the study of kinematics and dynamics of NC fluid. In the second part we construct an extension of the Friedmann-Robertson-Walker (FRW) cosmological model based on the NC fluid dynamics presented here. We outline the way in which NC effects generate cosmological perturbations bringing about anisotropy and inhomogeneity in the model. We also derive a NC extended Friedmann equation. (orig.)

Acoustic concentration of particles in fluid flow

Science.gov (United States)

Ward, Michael D.; Kaduchak, Gregory

2010-11-23

An apparatus for acoustic concentration of particles in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.

Acoustic concentration of particles in fluid flow

Science.gov (United States)

Ward, Michael W.; Kaduchak, Gregory

2017-08-15

Disclosed herein is a acoustic concentration of particles in a fluid flow that includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.

Materials processing using supercritical fluids

Directory of Open Access Journals (Sweden)

Orlović Aleksandar M.

2005-01-01

Full Text Available One of the most interesting areas of supercritical fluids applications is the processing of novel materials. These new materials are designed to meet specific requirements and to make possible new applications in Pharmaceuticals design, heterogeneous catalysis, micro- and nano-particles with unique structures, special insulating materials, super capacitors and other special technical materials. Two distinct possibilities to apply supercritical fluids in processing of materials: synthesis of materials in supercritical fluid environment and/or further processing of already obtained materials with the help of supercritical fluids. By adjusting synthesis parameters the properties of supercritical fluids can be significantly altered which further results in the materials with different structures. Unique materials can be also obtained by conducting synthesis in quite specific environments like reversed micelles. This paper is mainly devoted to processing of previously synthesized materials which are further processed using supercritical fluids. Several new methods have been developed to produce micro- and nano-particles with the use of supercritical fluids. The following methods: rapid expansion of supercritical solutions (RESS supercritical anti-solvent (SAS, materials synthesis under supercritical conditions and encapsulation and coating using supercritical fluids were recently developed.

“Unfriending” IV fluids. Where are we currently with fluid ...

African Journals Online (AJOL)

What end-points do we target once we decide to give fluids? • At what rate should fluid be administered? ... South African market, has been ascribed to many factors, including strong marketing. This marketing was ... However much of this work comes from severe sepsis and ongoing critical care. It is probably reasonable to ...

Fundamental Issues of Nano-fluid Behavior

International Nuclear Information System (INIS)

Williams, Wesley C.

2006-01-01

This paper will elucidate some of the behaviors of nano-fluids other than the abnormal conductivity enhancement, which are of importance to the experimental and engineering use of nano-fluids. Nano-fluid is the common name of any sol colloid involving nano-scale (less than 100 nm) sized particles dispersed within a base fluid. It has been shown previously that the dispersion of nano-particulate metallic oxides into water can increase thermal conductivity up to 30-40% over that of the base fluid and anomalously more than the mere weighed average of the colloid. There is a great potential for the use of nano-fluids as a way to enhance fluid/thermal energy transfer systems. Due to the recentness of nano-fluid science, there are still many issues which have not been fully investigated. This paper should act as a primer for the basic understanding of nano-fluid behavior. Particle size and colloid stability are of key importance to the functionality of nano-fluids. The pH and concentration/loading of nano-fluids can alter the size of the nano-particles and also the stability of the fluids. It will be shown through experiment and colloid theory the importance of these parameters. Furthermore, most of the existing literature uses volume percentage as the measure of particle loading, which can often be misleading. There will be discussion of this and other misleading ideas in nano-fluid science. (author)

Fluid Mechanics An Introduction to the Theory of Fluid Flows

CERN Document Server

Durst, Franz

2008-01-01

Advancements of fluid flow measuring techniques and of computational methods have led to new ways to treat laminar and turbulent flows. These methods are extensively used these days in research and engineering practise. This also requires new ways to teach the subject to students at higher educational institutions in an introductory manner. The book provides the knowledge to students in engineering and natural science needed to enter fluid mechanics applications in various fields. Analytical treatments are provided, based on the Navier-Stokes equations. Introductions are also given into numerical and experimental methods applied to flows. The main benefit the reader will derive from the book is a sound introduction into all aspects of fluid mechanics covering all relevant subfields.

Fluid flow behaviour of gas-condensate and near-miscible fluids at the pore scale

Energy Technology Data Exchange (ETDEWEB)

Dawe, Richard A. [Department of Chemical Engineering, University of West Indies, St. Augustine (Trinidad and Tobago); Grattoni, Carlos A. [Department of Earth Science and Engineering, Imperial College, London, SW7 2BP (United Kingdom)

2007-02-15

Retrograde condensate reservoir behaviour is complex with much of the detailed mechanisms of the multiphase fluid transport and mass transfer between the phases within the porous matrix still speculative. Visual modelling of selected processes occurring at the pore level under known and controlled boundary conditions can give an insight to fluid displacements at the core scale and help the interpretation of production behaviour at reservoir scale. Visualisation of the pore scale two-phase flow mechanisms has been studied experimentally at low interfacial tensions, < 0.5 mN/m, using a partially miscible fluid system in glass visual micro models. As the interfacial tension decreases the balance between fluid-fluid forces (interfacial, spreading and viscous) and fluid-solid interactions (wettability and viscous interactions) changes. Data measurements in the laboratory, particularly relative permeability, will therefore always be difficult especially for condensate fluids just below their dew point. What is certain is that gas production from a gas-condensate leads to condensate dropout when pressure falls below the dew point, either within the wellbore or, more importantly, in the reservoir. This paper illustrates some pore scale physics, particularly interfacial phenomena at low interfacial tension, which has relevance to appreciating the flow of condensate fluids close to their dew point either near the wellbore (which affects well productivity) or deep inside the reservoir (which affects condensate recovery). (author)

Hazards of organic working fluids

International Nuclear Information System (INIS)

Silberstein, S.

1977-08-01

We present several brief reviews on working fluids proposed for use in organic Rankine and bi-phase bottoming cycles. There are several general problems with many organic working fluids: flammability, toxicity, and a tendency to leak through seals. Besides, two of the proposed working fluids are to be used at temperatures above the manufacturer's maximum recommended temperature, and one is to be used in a way different from its customary usage. It may, in some cases, be more profitable to first seek alternative working fluids before committing large amounts of time and money to research projects on unsafe working fluids

Pleural fluid smear

Science.gov (United States)

... into the space around the lungs, called the pleural space. As fluid drains into a collection bottle, you may cough a bit. This is because your lung re-expands to fill the space where fluid had been. This sensation lasts for a few hours after the test.

Fluid control valves

International Nuclear Information System (INIS)

Rankin, J.

1980-01-01

A fluid control valve is described in which it is not necessary to insert a hand or a tool into the housing to remove the valve seat. Such a valve is particularly suitable for the control of radioactive fluids since maintenance by remote control is possible. (UK)

Recording fluid currents by holography

Science.gov (United States)

Heflinger, L. O.; Wuerker, R. F.

1980-01-01

Convection in fluids can be studied with aid of holographic apparatus that reveals three-dimensional motion of liquid. Apparatus eliminates images of fixed particles such as dust on windows and lenses, which might mask behavior of moving fluid particles. Holographic apparatus was developed for experiments on fluid convection cells under zero gravity. Principle is adaptable to study of fluid processes-for example, electrochemical plating and combustion in automotive engines.

Smart Fluid System Dually Responsive to Light and Electric Fields: An Electrophotorheological Fluid.

Science.gov (United States)

Yoon, Chang-Min; Jang, Yoonsun; Noh, Jungchul; Kim, Jungwon; Jang, Jyongsik

2017-10-24

Electrophotorheological (EPR) fluids, whose rheological activity is dually responsive to light and electric fields (E fields), is formulated by mixing photosensitive spiropyran-decorated silica (SP-sSiO 2 ) nanoparticles with zwitterionic lecithin and mineral oil. A reversible photorheological (PR) activity of the EPR fluid is developed via the binding and releasing mechanism of lecithin and merocyanine (MC, a photoisomerized form of SP) under ultraviolet (UV) and visible (VIS) light applications. Moreover, the EPR fluid exhibits an 8-fold higher electrorheological (ER) performance compared to the SP-sSiO 2 nanoparticle-based ER fluid (without lecithin) under an E field, which is attributed to the enhanced dielectric properties facilitated by the binding of the lecithin and SP molecules. Upon dual application of UV light and an E field, the EPR fluid exhibits high EPR performance (ca. 115.3 Pa) that far exceeds its separate PR (ca. 0.8 Pa) and ER (ca. 57.5 Pa) activities, because of the synergistic contributions of the PR and ER effects through rigid and fully connected fibril-like structures. Consequently, this study offers a strategy on formulation of dual-stimuli responsive smart fluid systems.

Microscope-Based Fluid Physics Experiments in the Fluids and Combustion Facility on ISS

Science.gov (United States)

Doherty, Michael P.; Motil, Susan M.; Snead, John H.; Malarik, Diane C.

2000-01-01

At the NASA Glenn Research Center, the Microgravity Science Program is planning to conduct a large number of experiments on the International Space Station in both the Fluid Physics and Combustion Science disciplines, and is developing flight experiment hardware for use within the International Space Station's Fluids and Combustion Facility. Four fluids physics experiments that require an optical microscope will be sequentially conducted within a subrack payload to the Fluids Integrated Rack of the Fluids and Combustion Facility called the Light Microscopy Module, which will provide the containment, changeout, and diagnostic capabilities to perform the experiments. The Light Microscopy Module is planned as a fully remotely controllable on-orbit microscope facility, allowing flexible scheduling and control of experiments within International Space Station resources. This paper will focus on the four microscope-based experiments, specifically, their objectives and the sample cell and instrument hardware to accommodate their requirements.

Viscoelastic gravel-pack carrier fluid

International Nuclear Information System (INIS)

Nehmer, W.L.

1988-01-01

The ability of a fluid to flow adequately into the formation during gravel-pack treatments is critical to achieving a good pack. Recent studies have indicated ''fish-eyes'' and/or ''microgels'' present in many polymer gelled carrier fluids will plug pore throats, leading to impaired leakoff and causing formation damage. Intensive manipulation of the polymer gelled fluid using shear and filter devices will help remove the particles, but it adds to the cost of the treatment in terms of equipment and manpower. Excessive shear will degrade the polymer leading to poor gravel suspension, while too little shear will cause filtration problems. A gelled carried fluid using a viscoelastic surfactant system has been found to leak off very efficiently to the formation, and cause no formation damage, without the use of shear/filter devices. Viscoelastic surfactant-base gelled fluids develop viscosity because of the association of surfactant moloecules into large rod-shaped aggregates. There is no hydration of polymer involved, so fish-eyes and microgels will not be formed in the viscoelastic fluid. A surfactant-base system having a yield point allows the gravel carrying properties to be much better than fluids gelled with conventional polymer systems (hydroxyethylcellulose [HEC]). For example, a gravel carried fluid gelled with 80 lb HEC/1,000 gal has a viscosity of about 400 cp at 170 sec/sup -1/; a viscoelastic surfactant-base system having only one-half the viscosity still flows into cores about four times more efficiently than the HEC-base fluid. The rheology, leakoff, formation damage and mixing properties of a viscoelastic, surfactant-base, gravel-pack carrier fluid are discussed

Raman spectroscopic signature of vaginal fluid and its potential application in forensic body fluid identification.

Science.gov (United States)

Sikirzhytskaya, Aliaksandra; Sikirzhytski, Vitali; Lednev, Igor K

2012-03-10

Traces of human body fluids, such as blood, saliva, sweat, semen and vaginal fluid, play an increasingly important role in forensic investigations. However, a nondestructive, easy and rapid identification of body fluid traces at the scene of a crime has not yet been developed. The obstacles have recently been addressed in our studies, which demonstrated the considerable potential of Raman spectroscopy. In this study, we continued to build a full library of body fluid spectroscopic signatures. The problems concerning vaginal fluid stain identification were addressed using Raman spectroscopy coupled with advanced statistical analysis. Calculated characteristic Raman and fluorescent spectral components were used to build a multidimensional spectroscopic signature of vaginal fluid, which demonstrated good specificity and was able to handle heterogeneous samples from different donors. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Relativistic thermodynamics of fluids

International Nuclear Information System (INIS)

Souriau, J.-M.

1977-05-01

The relativistic covariant definition of a statistical equilibrium, applied to a perfect gas, involves a 'temperature four-vector', whose direction is the mean velocity of the fluid, and whose length is the reciprocal temperature. The hypothesis of this 'temperature four-vector' being a relevant variable for the description of the dissipative motions of a simple fluid is discussed. The kinematics is defined by using a vector field and measuring the number of molecules. Such a dissipative fluid is subject to motions involving null entropy generation; the 'temperature four-vector' is then a Killing vector; the equations of motion can be completely integrated. Perfect fluids can be studied by this way and the classical results of Lichnerowicz are obtained. In weakly dissipative motions two viscosity coefficient appear together with the heat conductibility coefficient. Two other coefficients perharps measurable on real fluids. Phase transitions and shock waves are described with using the model [fr

Assessment of fluid-to-fluid modelling of critical heat flux in horizontal 37-element bundle flows

International Nuclear Information System (INIS)

Yang, S.K.

2006-01-01

Fluid-to-fluid modelling laws of critical heat flux (CHF) available in the literature were reviewed. The applicability of the fluid-to-fluid modelling laws was assessed using available data ranging from low to high mass fluxes in horizontal 37-element bundles simulating a CANDU fuel string. Correlations consisting of dimensionless similarity groups were derived using modelling fluid data (Freon-12) to predict water CHF data in horizontal 37-element bundles with uniform and non-uniform axial-heat flux distribution (AFD). The results showed that at mass fluxes higher than ∼4,000 kg/m 2 s (water equivalent value), the vertical fluid-to-fluid modelling laws of Ahmad (1973) and Katto (1979) predict water CHF in horizontal 37-element bundles with non-uniform AFD with average errors of 1.4% and 3.0% and RMS errors of 5.9% and 6.1%, respectively. The Francois and Berthoud (2003) fluid-to-fluid modelling law predicts CHF in non-uniformly heated 37-element bundles in the horizontal orientation with an average error of 0.6% and an RMS error of 10.4% over the available range of 2,000 to 6,200 kg/m 2 s. (author)

Fluid Mechanics and Fluid Power (FMFP)

Indian Academy of Sciences (India)

Amitabh Bhattacharya

of renewable energy (e.g., via wind, hydrokinetic generators), creating low-cost healthcare ... multiphase flow, turbulence, bio-fluid dynamics, atmospheric flows, microfluidic flows, and ... study the challenging problem of entry of solids in water.

Optimal composition of fluid-replacement beverages.

Science.gov (United States)

Baker, Lindsay B; Jeukendrup, Asker E

2014-04-01

The objective of this article is to provide a review of the fundamental aspects of body fluid balance and the physiological consequences of water imbalances, as well as discuss considerations for the optimal composition of a fluid replacement beverage across a broad range of applications. Early pioneering research involving fluid replacement in persons suffering from diarrheal disease and in military, occupational, and athlete populations incurring exercise- and/or heat-induced sweat losses has provided much of the insight regarding basic principles on beverage palatability, voluntary fluid intake, fluid absorption, and fluid retention. We review this work and also discuss more recent advances in the understanding of fluid replacement as it applies to various populations (military, athletes, occupational, men, women, children, and older adults) and situations (pathophysiological factors, spaceflight, bed rest, long plane flights, heat stress, altitude/cold exposure, and recreational exercise). We discuss how beverage carbohydrate and electrolytes impact fluid replacement. We also discuss nutrients and compounds that are often included in fluid-replacement beverages to augment physiological functions unrelated to hydration, such as the provision of energy. The optimal composition of a fluid-replacement beverage depends upon the source of the fluid loss, whether from sweat, urine, respiration, or diarrhea/vomiting. It is also apparent that the optimal fluid-replacement beverage is one that is customized according to specific physiological needs, environmental conditions, desired benefits, and individual characteristics and taste preferences.

Insertable fluid flow passage bridgepiece and method

Science.gov (United States)

Jones, Daniel O.

2000-01-01

A fluid flow passage bridgepiece for insertion into an open-face fluid flow channel of a fluid flow plate is provided. The bridgepiece provides a sealed passage from a columnar fluid flow manifold to the flow channel, thereby preventing undesirable leakage into and out of the columnar fluid flow manifold. When deployed in the various fluid flow plates that are used in a Proton Exchange Membrane (PEM) fuel cell, bridgepieces of this invention prevent mixing of reactant gases, leakage of coolant or humidification water, and occlusion of the fluid flow channel by gasket material. The invention also provides a fluid flow plate assembly including an insertable bridgepiece, a fluid flow plate adapted for use with an insertable bridgepiece, and a method of manufacturing a fluid flow plate with an insertable fluid flow passage bridgepiece.

Fluid dynamics of dilatant fluid

DEFF Research Database (Denmark)

Nakanishi, Hiizu; Nagahiro, Shin-ichiro; Mitarai, Namiko

2012-01-01

of the state variable, we demonstrate that the model can describe basic features of the dilatant fluid such as the stress-shear rate curve that represents discontinuous severe shear thickening, hysteresis upon changing shear rate, and instantaneous hardening upon external impact. An analysis of the model...

Thermostating highly confined fluids.

Science.gov (United States)

Bernardi, Stefano; Todd, B D; Searles, Debra J

2010-06-28

In this work we show how different use of thermostating devices and modeling of walls influence the mechanical and dynamical properties of confined nanofluids. We consider a two dimensional fluid undergoing Couette flow using nonequilibrium molecular dynamics simulations. Because the system is highly inhomogeneous, the density shows strong fluctuations across the channel. We compare the dynamics produced by applying a thermostating device directly to the fluid with that obtained when the wall is thermostated, considering also the effects of using rigid walls. This comparison involves an analysis of the chaoticity of the fluid and evaluation of mechanical properties across the channel. We look at two thermostating devices with either rigid or vibrating atomic walls and compare them with a system only thermostated by conduction through vibrating atomic walls. Sensitive changes are observed in the xy component of the pressure tensor, streaming velocity, and density across the pore and the Lyapunov localization of the fluid. We also find that the fluid slip can be significantly reduced by rigid walls. Our results suggest caution in interpreting the results of systems in which fluid atoms are thermostated and/or wall atoms are constrained to be rigid, such as, for example, water inside carbon nanotubes.

Amniotic fluid embolism

Directory of Open Access Journals (Sweden)

Kiranpreet Kaur

2016-01-01

Full Text Available Amniotic fluid embolism (AFE is one of the catastrophic complications of pregnancy in which amniotic fluid, fetal cells, hair, or other debris enters into the maternal pulmonary circulation, causing cardiovascular collapse. Etiology largely remains unknown, but may occur in healthy women during labour, during cesarean section, after abnormal vaginal delivery, or during the second trimester of pregnancy. It may also occur up to 48 hours post-delivery. It can also occur during abortion, after abdominal trauma, and during amnio-infusion. The pathophysiology of AFE is not completely understood. Possible historical cause is that any breach of the barrier between maternal blood and amniotic fluid forces the entry of amniotic fluid into the systemic circulation and results in a physical obstruction of the pulmonary circulation. The presenting signs and symptoms of AFE involve many organ systems. Clinical signs and symptoms are acute dyspnea, cough, hypotension, cyanosis, fetal bradycardia, encephalopathy, acute pulmonary hypertension, coagulopathy etc. Besides basic investigations lung scan, serum tryptase levels, serum levels of C3 and C4 complements, zinc coproporphyrin, serum sialyl Tn etc are helpful in establishing the diagnosis. Treatment is mainly supportive, but exchange transfusion, extracorporeal membrane oxygenation, and uterine artery embolization have been tried from time to time. The maternal prognosis after amniotic fluid embolism is very poor though infant survival rate is around 70%.

Imaging of small amounts of pleural fluid. Part two - physiologic pleural fluid

International Nuclear Information System (INIS)

Kocijancic, I.

2006-01-01

Background. There are only a few articles reporting the possibility of radiographic and sonographic detection of physiologic pleural fluid in healthy individuals. In the last decade the advent of sonographic equipments enables the detection of small amounts of physiologic pleural fluid in about 20% of healthy individuals. In certain physiologic conditions (i.e. pregnancy) the physiologic pleural fluid could be detected more frequently by chest ultrasonography. Conclusions. A positive result, if detected, should not be taken as a sign of the occult thoracic disease. (author)

Numerical Analysis of Mixed Fluid Jet Flows through Cutting Fluid Supplying Nozzle

OpenAIRE

S, Chung; B, Shin

2017-01-01

Metal cutting operation involves generation of heat due to friction between the tool and the cutting materials. This heat needs to be carried away otherwise it creates white spots. To reduce this abnormal heat cutting fluid is used. Cutting fluid also has an important role in the lubrication of the cutting edges of machine tools and the pieces, and in sluicing away the resulting swarf. As a cutting fluid, water is a great conductor of heat but is not stable at high temperatures, so to improve...

Proceedings of the sixth international and forty third national conference on fluid mechanics and fluid power: book of abstracts

International Nuclear Information System (INIS)

Jain, Anuj; Paul, Akshoy Ranjan

2016-01-01

Fluid Mechanics and Fluid Power (FMFP) Conference is an important meeting to promote all activities in the field of Fluid Mechanics and Fluid Power in India. FMFP-2016 offers great opportunity to scientists, researchers, engineers and business executives from all parts of the world to share the recent advancements and future trends in all aspects of fluid mechanics and fluid power- be it theoretical, experimental, applied and computational, and build network. It covers theoretical and experimental fluid dynamics, flow instability, transition, turbulence and control, fluid machinery, turbomachinery and fluid power, IC engines and gas turbines, multiphase flows, fluid-structure interaction and flow-induced noise, micro and nano fluid mechanics, bio-inspired fluid mechanics, energy and environment, specialized topics (transport phenomena in materials processing and manufacturing, MHD and EHD flows, granular flows, nuclear reactor, thermal hydraulics, defence and space engineering, sustainable habitat. Papers relevant to INIS are indexed separately

Fluid dynamics

CERN Document Server

Ruban, Anatoly I

This is the first book in a four-part series designed to give a comprehensive and coherent description of Fluid Dynamics, starting with chapters on classical theory suitable for an introductory undergraduate lecture course, and then progressing through more advanced material up to the level of modern research in the field. The present Part 1 consists of four chapters. Chapter 1 begins with a discussion of Continuum Hypothesis, which is followed by an introduction to macroscopic functions, the velocity vector, pressure, density, and enthalpy. We then analyse the forces acting inside a fluid, and deduce the Navier-Stokes equations for incompressible and compressible fluids in Cartesian and curvilinear coordinates. In Chapter 2 we study the properties of a number of flows that are presented by the so-called exact solutions of the Navier-Stokes equations, including the Couette flow between two parallel plates, Hagen-Poiseuille flow through a pipe, and Karman flow above an infinite rotating disk. Chapter 3 is d...

Handbook of hydraulic fluid technology

CERN Document Server

Totten, George E

2011-01-01

""The Handbook of Hydraulic Fluid Technology"" serves as the foremost resource for designing hydraulic systems and for selecting hydraulic fluids used in engineering applications. Featuring new illustrations, data tables, as well as practical examples, this second edition is updated with essential information on the latest hydraulic fluids and testing methods. The detailed text facilitates unparalleled understanding of the total hydraulic system, including important hardware, fluid properties, and hydraulic lubricants. Written by worldwide experts, the book also offers a rigorous overview of h

Metalworking and machining fluids

Science.gov (United States)

Erdemir, Ali; Sykora, Frank; Dorbeck, Mark

2010-10-12

Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction, prevent galling and severe wear problems on cutting and forming tools.

Disposing of fluid wastes

International Nuclear Information System (INIS)

Bradley, J.S.

1984-01-01

Toxic liquid waste, eg liquid radioactive waste, is disposed of by locating a sub-surface stratum which, before removal of any fluid, has a fluid pressure in the pores thereof which is less than the hydrostatic pressure which is normal for a stratum at that depth in the chosen area, and then feeding the toxic liquid into the stratum at a rate such that the fluid pressure in the stratum never exceeds the said normal hydrostatic pressure. (author)

Steady laminar flow of fractal fluids

Energy Technology Data Exchange (ETDEWEB)

Balankin, Alexander S., E-mail: abalankin@ipn.mx [Grupo Mecánica Fractal, ESIME, Instituto Politécnico Nacional, México D.F., 07738 (Mexico); Mena, Baltasar [Laboratorio de Ingeniería y Procesos Costeros, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Sisal, Yucatán, 97355 (Mexico); Susarrey, Orlando; Samayoa, Didier [Grupo Mecánica Fractal, ESIME, Instituto Politécnico Nacional, México D.F., 07738 (Mexico)

2017-02-12

We study laminar flow of a fractal fluid in a cylindrical tube. A flow of the fractal fluid is mapped into a homogeneous flow in a fractional dimensional space with metric induced by the fractal topology. The equations of motion for an incompressible Stokes flow of the Newtonian fractal fluid are derived. It is found that the radial distribution for the velocity in a steady Poiseuille flow of a fractal fluid is governed by the fractal metric of the flow, whereas the pressure distribution along the flow direction depends on the fractal topology of flow, as well as on the fractal metric. The radial distribution of the fractal fluid velocity in a steady Couette flow between two concentric cylinders is also derived. - Highlights: • Equations of Stokes flow of Newtonian fractal fluid are derived. • Pressure distribution in the Newtonian fractal fluid is derived. • Velocity distribution in Poiseuille flow of fractal fluid is found. • Velocity distribution in a steady Couette flow is established.

Cosmology with moving bimetric fluids

Energy Technology Data Exchange (ETDEWEB)

García-García, Carlos; Maroto, Antonio L.; Martín-Moruno, Prado, E-mail: cargar08@ucm.es, E-mail: maroto@ucm.es, E-mail: pradomm@ucm.es [Departamento de Física Teórica I, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

2016-12-01

We study cosmological implications of bigravity and massive gravity solutions with non-simultaneously diagonal metrics by considering the generalized Gordon and Kerr-Schild ansatzes. The scenario that we obtain is equivalent to that of General Relativity with additional non-comoving perfect fluids. We show that the most general ghost-free bimetric theory generates three kinds of effective fluids whose equations of state are fixed by a function of the ansatz. Different choices of such function allow to reproduce the behaviour of different dark fluids. In particular, the Gordon ansatz is suitable for the description of various kinds of slowly-moving fluids, whereas the Kerr-Schild one is shown to describe a null dark energy component. The motion of those dark fluids with respect to the CMB is shown to generate, in turn, a relative motion of baryonic matter with respect to radition which contributes to the CMB anisotropies. CMB dipole observations are able to set stringent limits on the dark sector described by the effective bimetric fluid.

Fluid mechanics fundamentals and applications

CERN Document Server

Cengel, Yunus

2013-01-01

Cengel and Cimbala's Fluid Mechanics Fundamentals and Applications, communicates directly with tomorrow's engineers in a simple yet precise manner. The text covers the basic principles and equations of fluid mechanics in the context of numerous and diverse real-world engineering examples. The text helps students develop an intuitive understanding of fluid mechanics by emphasizing the physics, using figures, numerous photographs and visual aids to reinforce the physics. The highly visual approach enhances the learning of Fluid mechanics by students. This text distinguishes itself from others by the way the material is presented - in a progressive order from simple to more difficult, building each chapter upon foundations laid down in previous chapters. In this way, even the traditionally challenging aspects of fluid mechanics can be learned effectively. McGraw-Hill is also proud to offer ConnectPlus powered by Maple with the third edition of Cengel/Cimbabla, Fluid Mechanics. This innovative and powerful new sy...

Fluid-structure finite-element vibrational analysis

Science.gov (United States)

Feng, G. C.; Kiefling, L.

1974-01-01

A fluid finite element has been developed for a quasi-compressible fluid. Both kinetic and potential energy are expressed as functions of nodal displacements. Thus, the formulation is similar to that used for structural elements, with the only differences being that the fluid can possess gravitational potential, and the constitutive equations for fluid contain no shear coefficients. Using this approach, structural and fluid elements can be used interchangeably in existing efficient sparse-matrix structural computer programs such as SPAR. The theoretical development of the element formulations and the relationships of the local and global coordinates are shown. Solutions of fluid slosh, liquid compressibility, and coupled fluid-shell oscillation problems which were completed using a temporary digital computer program are shown. The frequency correlation of the solutions with classical theory is excellent.

Lennard-Jones fluids in two-dimensional nano-pores. Multi-phase coexistence and fluid structure

Science.gov (United States)

Yatsyshin, Petr; Savva, Nikos; Kalliadasis, Serafim

2014-03-01

We present a number of fundamental findings on the wetting behaviour of nano-pores. A popular model for fluid confinement is a one-dimensional (1D) slit pore formed by two parallel planar walls and it exhibits capillary condensation (CC): a first-order phase transition from vapour to capillary-liquid (Kelvin shift). Capping such a pore at one end by a third orthogonal wall forms a prototypical two-dimensional (2D) pore. We show that 2D pores possess a wetting temperature such that below this temperature CC remains of first order, above it becomes a continuous phase transition manifested by a slab of capillary-liquid filling the pore from the capping wall. Continuous CC exhibits hysteresis and can be preceded by a first-order capillary prewetting transition. Additionally, liquid drops can form in the corners of the 2D pore (remnant of 2D wedge prewetting). The three fluid phases, vapour, capillary-liquid slab and corner drops, can coexist at the pore triple point. Our model is based on the statistical mechanics of fluids in the density functional formulation. The fluid-fluid and fluid-substrate interactions are dispersive. We analyze in detail the microscopic fluid structure, isotherms and full phase diagrams. Our findings also suggest novel ways to control wetting of nano-pores. We are grateful to the European Research Council via Advanced Grant No. 247031 for support.

Gyro-fluid and two-fluid theory and simulations of edge-localized-modes

Energy Technology Data Exchange (ETDEWEB)

Xu, X. Q.; Dimits, A.; Joseph, I.; Umansky, M. V. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Xi, P. W. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); School of Physics, Peking University, Beijing (China); Xia, T. Y.; Gui, B. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Kim, S. S.; Park, G. Y.; Rhee, T.; Jhang, H. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejon 305-333 (Korea, Republic of); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejon 305-333 (Korea, Republic of); Center for Astrophysics and Space Sciences and Department of Physics, University of California, San Diego, La Jolla, California 92093-0424 (United States); Dudson, B. [University of York, Heslington, York YO10 5DD (United Kingdom); Snyder, P. B. [General Atomics, San Diego, California 92186 (United States)

2013-05-15

This paper reports on the theoretical and simulation results of a gyro-Landau-fluid extension of the BOUT++ code, which contributes to increasing the physics understanding of edge-localized-modes (ELMs). Large ELMs with low-to-intermediate-n peeling-ballooning (P-B) modes are significantly suppressed due to finite Larmor radius (FLR) effects when the ion temperature increases. For type-I ELMs, it is found from linear simulations that retaining complete first order FLR corrections as resulting from the incomplete “gyroviscous cancellation” in Braginskii's two-fluid model is necessary to obtain good agreement with gyro-fluid results for high ion temperature cases (T{sub i}≽3 keV) when the ion density has a strong radial variation, which goes beyond the simple local model of ion diamagnetic stabilization of ideal ballooning modes. The maximum growth rate is inversely proportional to T{sub i} because the FLR effect is proportional to T{sub i}. The FLR effect is also proportional to toroidal mode number n, so for high n cases, the P-B mode is stabilized by FLR effects. Nonlinear gyro-fluid simulations show results that are similar to those from the two-fluid model, namely that the P-B modes trigger magnetic reconnection, which drives the collapse of the pedestal pressure. Due to the additional FLR-corrected nonlinear E × B convection of the ion gyro-center density, for a ballooning-dominated equilibrium the gyro-fluid model further limits the radial spreading of ELMs. In six-field two fluid simulations, the parallel thermal diffusivity is found to prevent the ELM encroachment further into core plasmas and therefore leads to steady state L-mode profiles. The simulation results show that most energy is lost via ion channel during an ELM event, followed by particle loss and electron energy loss. Because edge plasmas have significant spatial inhomogeneities and complicated boundary conditions, we have developed a fast non-Fourier method for the computation of

Binary non-additive hard sphere mixtures: fluid demixing, asymptotic decay of correlations and free fluid interfaces

International Nuclear Information System (INIS)

Hopkins, Paul; Schmidt, Matthias

2010-01-01

Using a fundamental measure density functional theory we investigate both bulk and inhomogeneous systems of the binary non-additive hard sphere model. For sufficiently large (positive) non-additivity the mixture phase separates into two fluid phases with different compositions. We calculate bulk fluid-fluid coexistence curves for a range of size ratios and non-additivity parameters and find that they compare well to simulation results from the literature. Using the Ornstein-Zernike equation, we investigate the asymptotic, r→∞, decay of the partial pair correlation functions, g ij (r). At low densities a structural crossover occurs in the asymptotic decay between two different damped oscillatory modes with different wavelengths corresponding to the two intra-species hard-core diameters. On approaching the fluid-fluid critical point there is a Fisher-Widom crossover from exponentially damped oscillatory to monotonic asymptotic decay. Using the density functional we calculate the density profiles for the planar free fluid-fluid interface between coexisting fluid phases. We show that the type of asymptotic decay of g ij (r) not only determines the asymptotic decay of the interface profiles, but is also relevant for intermediate and even short-ranged behaviour. We also determine the surface tension of the free fluid interface, finding that it increases with non-additivity, and that on approaching the critical point mean-field scaling holds.

Fast intraslab fluid-flow events linked to pulses of high pore fluid pressure at the subducted plate interface

Science.gov (United States)

Taetz, Stephan; John, Timm; Bröcker, Michael; Spandler, Carl; Stracke, Andreas

2018-01-01

A better understanding of the subduction zone fluid cycle and its chemical-mechanical feedback requires in-depth knowledge about how fluids flow within and out of descending slabs. Relicts of fluid-flow systems in exhumed rocks of fossil subduction zones allow for identification of the general relationships between dehydration reactions, fluid pathway formation, the dimensions and timescales of distinct fluid flow events; all of which are required for quantitative models for fluid-induced subduction zone processes. Two types of garnet-quartz-phengite veins can be distinguished in an eclogite-facies mélange block from the Pouébo Eclogite Mélange, New Caledonia. These veins record synmetamorphic internal fluid release by mineral breakdown reactions (type I veins), and infiltration of an external fluid (type II veins) with the associated formation of a reaction selvage. The dehydration and fluid migration documented by the type I veins likely occurred on a timescale of 105-106 years, based on average subduction rates and metamorphic conditions required for mineral dehydration and fluid flow. The timeframe of fluid-rock interaction between the external fluid and the wall-rock of the type II veins is quantified using a continuous bulk-rock Li-diffusion profile perpendicular to a vein and its metasomatic selvage. Differences in Li concentration between the internal and external fluid reservoirs resulted in a distinct diffusion profile (decreasing Li concentration and increasing δ7 Li) as the reaction front propagated into the host rock. Li-chronometric constraints indicate that the timescales of fluid-rock interaction associated with type II vein formation are on the order of 1 to 4 months (0.150-0.08+0.14 years). The short-lived, pulse-like character of this process is consistent with the notion that fluid flow caused by oceanic crust dehydration at the blueschist-to-eclogite transition contributes to or even dominates episodic pore fluid pressure increases at the

Black holes as lumps of fluid

International Nuclear Information System (INIS)

Caldarelli, Marco M.; Dias, Oscar J.C.; Emparan, Roberto; Klemm, Dietmar

2009-01-01

The old suggestive observation that black holes often resemble lumps of fluid has recently been taken beyond the level of an analogy to a precise duality. We investigate aspects of this duality, and in particular clarify the relation between area minimization of the fluid vs. area maximization of the black hole horizon, and the connection between surface tension and curvature of the fluid, and surface gravity of the black hole. We also argue that the Rayleigh-Plateau instability in a fluid tube is the holographic dual of the Gregory-Laflamme instability of a black string. Associated with this fluid instability there is a rich variety of phases of fluid solutions that we study in detail, including in particular the effects of rotation. We compare them against the known results for asymptotically flat black holes finding remarkable agreement. Furthermore, we use our fluid results to discuss the unknown features of the gravitational system. Finally, we make some observations that suggest that asymptotically flat black holes may admit a fluid description in the limit of large number of dimensions.

Lectures on fluid mechanics

CERN Document Server

Shinbrot, Marvin

2012-01-01

Readable and user-friendly, this high-level introduction explores the derivation of the equations of fluid motion from statistical mechanics, classical theory, and a portion of the modern mathematical theory of viscous, incompressible fluids. 1973 edition.

Performance Testing of Cutting Fluids

DEFF Research Database (Denmark)

Belluco, Walter

The importance of cutting fluid performance testing has increased with documentation requirements of new cutting fluid formulations based on more sustainable products, as well as cutting with minimum quantity of lubrication and dry cutting. Two sub-problems have to be solved: i) which machining...... tests feature repeatability, reproducibility and sensitivity to cutting fluids, and ii) to what extent results of one test ensure relevance to a wider set of machining situations. The present work is aimed at assessing the range of validity of the different testing methods, investigating correlation...... within the whole range of operations, materials, cutting fluids, operating conditions, etc. Cutting fluid performance was evaluated in turning, drilling, reaming and tapping, and with respect to tool life, cutting forces, chip formation and product quality (dimensional accuracy and surface integrity...

Pitch-catch only ultrasonic fluid densitometer

Science.gov (United States)

Greenwood, M.S.; Harris, R.V.

1999-03-23

The present invention is an ultrasonic fluid densitometer that uses a material wedge and pitch-catch only ultrasonic transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface. 6 figs.

Application of ADINA fluid element for transient response analysis of fluid-structure system

International Nuclear Information System (INIS)

Sakurai, Y.; Kodama, T.; Shiraishi, T.

1985-01-01

Pressure propagation and Fluid-Structure Interaction (FSI) in 3D space were simulated by general purpose finite element program ADINA using the displacement-based fluid element which presumes inviscid and compressible fluid with no net flow. Numerical transient solution was compared with the measured data of an FSI experiment and was found to fairly agree with the measured. In the next step, post analysis was conducted for a blowdown experiment performed with a 1/7 scaled reactor pressure vessel and a flexible core barrel and the code performance was found to be satisfactory. It is concluded that the transient response of the core internal structure of a PWR during the initial stage of LOCA can be analyzed by the displacement-based finite fluid element and the structural element. (orig.)

Compressible generalized Newtonian fluids

Czech Academy of Sciences Publication Activity Database

Málek, Josef; Rajagopal, K.R.

2010-01-01

Roč. 61, č. 6 (2010), s. 1097-1110 ISSN 0044-2275 Institutional research plan: CEZ:AV0Z20760514 Keywords : power law fluid * uniform temperature * compressible fluid Subject RIV: BJ - Thermodynamics Impact factor: 1.290, year: 2010

Cerebrospinal fluid leak (image)

Science.gov (United States)

... brain and spinal cord by acting like a liquid cushion. The fluid allows the organs to be buoyant protecting them from blows or other trauma. Inside the skull the cerebrospinal fluid is contained by the dura which covers ...

Fluid Dynamics for Physicists

Science.gov (United States)

Faber, T. E.

1995-08-01

This textbook provides an accessible and comprehensive account of fluid dynamics that emphasizes fundamental physical principles and stresses connections with other branches of physics. Beginning with a basic introduction, the book goes on to cover many topics not typically treated in texts, such as compressible flow and shock waves, sound attenuation and bulk viscosity, solitary waves and ship waves, thermal convection, instabilities, turbulence, and the behavior of anisotropic, non-Newtonian and quantum fluids. Undergraduate or graduate students in physics or engineering who are taking courses in fluid dynamics will find this book invaluable.

[Arterial pressure curve and fluid status].

Science.gov (United States)

Pestel, G; Fukui, K

2009-04-01

Fluid optimization is a major contributor to improved outcome in patients. Unfortunately, anesthesiologists are often in doubt whether an additional fluid bolus will improve the hemodynamics of the patient or not as excess fluid may even jeopardize the condition. This article discusses physiological concepts of liberal versus restrictive fluid management followed by a discussion on the respective capabilities of various monitors to predict fluid responsiveness. The parameter difference in pulse pressure (dPP), derived from heart-lung interaction in mechanically ventilated patients is discussed in detail. The dPP cutoff value of 13% to predict fluid responsiveness is presented together with several assessment techniques of dPP. Finally, confounding variables on dPP measurements, such as ventilation parameters, pneumoperitoneum and use of norepinephrine are also mentioned.

Review of a fluid resuscitation protocol: "fluid creep" is not due to nursing error.

Science.gov (United States)

Faraklas, Iris; Cochran, Amalia; Saffle, Jeffrey

2012-01-01

Recent reviews of burn resuscitation have included the suggestion that "fluid creep" may be influenced by practitioner error. Our center uses a nursing-driven resuscitation protocol that permits titration of fluid based on hourly urine output, including the addition of colloid when patients fail to respond appropriately. The purpose of this study was to examine protocol compliance. We reviewed 140 patients (26 children) with burns of ≥20% TBSA who received protocol-directed resuscitation from 2005 to 2010. We compared each patient's actual hourly fluid infusion with that predicted by the protocol. Sixty-seven patients (48%) completed resuscitation using crystalloid alone, whereas 73 patients required colloid supplementation. Groups did not differ in age, gender, weight, or time from injury to admission. Patients requiring colloid had larger median total burns (33.0 vs 23.5% TBSA) and full-thickness burns (15.5 vs 4.5% TBSA) and more inhalation injuries (60.3 vs 28.4%; P patients had median predicted requirements of 5.4 ml/kg/%TBSA. Crystalloid-only patients required fluid volumes close to Parkland predictions (4.7 ml/kg/%TBSA), whereas patients who received colloid required more fluid than the predicted volume (7.5 ml/kg/%TBSA). However, the hourly difference between the predicted and received fluids was a median of only 1.0% (interquartile range: -6.1 to 11.1%) and did not differ between groups. Pediatric patients had greater calculated differences than adults. Crystalloid patients exhibited higher urine outputs than colloid patients until colloid was started, suggesting that early over-resuscitation did not contribute to fluid creep. Adherence to our protocol for burn shock resuscitation was excellent overall. Fluid creep exhibited by more seriously injured patients was not due to nurses' failure to follow the protocol. This review has illuminated some opportunities for practice improvement, possibly using a computerized decision support system.

The fluid dynamics of climate

CERN Document Server

Palazzi, Elisa; Fraedrich, Klaus

2016-01-01

This volume provides an overview of the fluid aspects of the climate system, focusing on basic aspects as well as recent research developments. It will bring together contributions from diverse fields of the physical, mathematical and engineering sciences. The volume will be useful to doctorate students, postdocs and researchers working on different aspects of atmospheric, oceanic and environmental fluid dynamics. It will also be of interest to researchers interested in quantitatively understanding how fluid dynamics can be applied to the climate system, and to climate scientists willing to gain a deeper insight into the fluid mechanics underlying climate processes.

Fluids in micropores. II. Self-diffusion in a simple classical fluid in a slit pore

International Nuclear Information System (INIS)

Schoen, M.; Cushman, J.H.; Diestler, D.J.; Rhykerd, C.L. Jr.

1988-01-01

Self-diffusion coefficients D are computed for a model slit pore consisting of a rare-gas fluid confined between two parallel face-centered cubic (100) planes (walls) of rigidly fixed rare-gas atoms. By means of an optimally vectorized molecular-dynamics program for the CYBER 205, the dependence of D on the thermodynamic state (specified by the chemical potential μ, temperature T, and the pore width h) of the pore fluid has been explored. Diffusion is governed by Fick's law, even in pores as narrow as 2 or 3 atomic diameters. The diffusion coefficient oscillates as a function of h with fixed μ and T, vanishing at critical values of h, where fluid--solid phase transitions occur. A shift of the pore walls relative to one another in directions parallel with the walls can radically alter the structure of the pore fluid and consequently the magnitude of D. Since the pore fluid forms distinct layers parallel to the walls, a local diffusion coefficient D/sup (//sup i//sup )//sub parallel/ associated with a given layer i can be defined. D/sup (//sup i//sup )//sub parallel/ is least for the contact layer, even for pores as wide as 30 atomic diameters (∼100 A). Moreover, D/sup (//sup i//sup )//sub parallel/ increases with increasing distance of the fluid layer from the wall and, for pore widths between 16 and 30 atomic diameters, D/sup (//sup i//sup )//sub parallel/ is larger in the center of the pore than in the bulk fluid that is in equilibrium with the pore fluid. The opposite behavior is observed in corresponding smooth-wall pores, in which the discrete fluid--wall interactions have been averaged by smearing the wall atoms over the plane of the wall

Fluid migration studies in salt

International Nuclear Information System (INIS)

Shefelbine, H.C.; Raines, G.E.

1980-01-01

This discussion will be limited to the migration of water trapped in the rock salt under the influence of the heat field produced by nuclear waste. This is of concern because hypotheticl scenarios have been advanced in which this fluid movement allows radionuclides to escape to the biosphere. While portions of these scenarios are supported by observation, none of the complete scenarios has been demonstrated. The objectives of the present fluid migration studies are two-fold: 1. determine the character of the trapped fluid in terms of quantity, habitat and chemical constituents; and 2. define the mechanisms that cause the fluid to migrate toward heat sources. Based on the observations to date, fluid migration will not have a major impact on repository integrity. However, the above objectives will be pursued until the impacts, if any, can be quantified

Direct differentiation of the quasi-incompressible fluid formulation of fluid-structure interaction using the PFEM

Science.gov (United States)

Zhu, Minjie; Scott, Michael H.

2017-07-01

Accurate and efficient response sensitivities for fluid-structure interaction (FSI) simulations are important for assessing the uncertain response of coastal and off-shore structures to hydrodynamic loading. To compute gradients efficiently via the direct differentiation method (DDM) for the fully incompressible fluid formulation, approximations of the sensitivity equations are necessary, leading to inaccuracies of the computed gradients when the geometry of the fluid mesh changes rapidly between successive time steps or the fluid viscosity is nonzero. To maintain accuracy of the sensitivity computations, a quasi-incompressible fluid is assumed for the response analysis of FSI using the particle finite element method and DDM is applied to this formulation, resulting in linearized equations for the response sensitivity that are consistent with those used to compute the response. Both the response and the response sensitivity can be solved using the same unified fractional step method. FSI simulations show that although the response using the quasi-incompressible and incompressible fluid formulations is similar, only the quasi-incompressible approach gives accurate response sensitivity for viscous, turbulent flows regardless of time step size.

Bioimpedance-Guided Fluid Management in Hemodialysis Patients

Science.gov (United States)

Arias-Guillén, Marta; Wabel, Peter; Fontseré, Néstor; Carrera, Montserrat; Campistol, José Maria; Maduell, Francisco

2013-01-01

Summary Background and objectives Achieving and maintaining optimal fluid status remains a major challenge in hemodialysis therapy. The aim of this interventional study was to assess the feasibility and clinical consequences of active fluid management guided by bioimpedance spectroscopy in chronic hemodialysis patients. Design, setting, participants, & measurements Fluid status was optimized prospectively in 55 chronic hemodialysis patients over 3 months (November 2011 to February 2012). Predialysis fluid overload was measured weekly using the Fresenius Body Composition Monitor. Time-averaged fluid overload was calculated as the average between pre- and postdialysis fluid overload. The study aimed to bring the time-averaged fluid overload of all patients into a target range of 0.5±0.75 L within the first month and maintain optimal fluid status until study end. Postweight was adjusted weekly according to a predefined protocol. Results Time-averaged fluid overload in the complete study cohort was 0.9±1.6 L at baseline and 0.6±1.1 L at study end. Time-averaged fluid overload decreased by −1.20±1.32 L (P<0.01) in the fluid-overloaded group (n=17), remained unchanged in the normovolemic group (n=26, P=0.59), and increased by 0.59±0.76 L (P=0.02) in the dehydrated group (n=12). Every 1 L change in fluid overload was accompanied by a 9.9 mmHg/L change in predialysis systolic BP (r=0.55, P<0.001). At study end, 76% of all patients were either on time-averaged fluid overload target or at least closer to target than at study start. The number of intradialytic symptoms did not change significantly in any of the subgroups. Conclusions Active fluid management guided by bioimpedance spectroscopy was associated with an improvement in overall fluid status and BP. PMID:23949235

Fluid discrimination based on rock physics templates

International Nuclear Information System (INIS)

Liu, Qian; Yin, Xingyao; Li, Chao

2015-01-01

Reservoir fluid discrimination is an indispensable part of seismic exploration. Reliable fluid discrimination helps to decrease the risk of exploration and to increase the success ratio of drilling. There are many kinds of fluid indicators that are used in fluid discriminations, most of which are single indicators. But single indicators do not always work well under complicated reservoir conditions. Therefore, combined fluid indicators are needed to increase accuracies of discriminations. In this paper, we have proposed an alternative strategy for the combination of fluid indicators. An alternative fluid indicator, the rock physics template-based indicator (RPTI) has been derived to combine the advantages of two single indicators. The RPTI is more sensitive to the contents of fluid than traditional indicators. The combination is implemented based on the characteristic of the fluid trend in the rock physics template, which means few subjective factors are involved. We also propose an inversion method to assure the accuracy of the RPTI input data. The RPTI profile is an intuitionistic interpretation of fluid content. Real data tests demonstrate the applicability and validity. (paper)

Amniotic Fluid Cells Show Higher Pluripotency-Related Gene Expression Than Allantoic Fluid Cells.

Science.gov (United States)

Kehl, Debora; Generali, Melanie; Görtz, Sabrina; Geering, Diego; Slamecka, Jaroslav; Hoerstrup, Simon P; Bleul, Ulrich; Weber, Benedikt

2017-10-01

Amniotic fluid represents an abundant source of multipotent stem cells, referred as broadly multipotent given their differentiation potential and expression of pluripotency-related genes. However, the origin of this broadly multipotent cellular fraction is not fully understood. Several sources have been proposed so far, including embryonic and extraembryonic tissues. In this regard, the ovine developmental model uniquely allows for direct comparison of fetal fluid-derived cells from two separate fetal fluid cavities, the allantois and the amnion, over the entire duration of gestation. As allantoic fluid mainly collects fetal urine, cells originating from the efferent urinary tract can directly be compared with cells deriving from the extraembryonic amniotic tissues and the fetus. This study shows isolation of cells from the amniotic [ovine amniotic fluid cells (oAFCs)] and allantoic fluid [ovine allantoic fluid cells (oALCs)] in a strictly paired fashion with oAFCs and oALCs derived from the same fetus. Both cell types showed cellular phenotypes comparable to standard mesenchymal stem cells (MSCs), with trilineage differentiation potential, and expression of common ovine MSC markers. However, the expression of MSC markers per single cell was higher in oAFCs as measured by flow cytometry. oAFCs exhibited higher proliferative capacities and showed significantly higher expression of pluripotency-related genes OCT4, STAT3, NANOG, and REX1 by quantitative real-time polymerase chain reaction compared with paired oALCs. No significant decrease of pluripotency-related gene expression was noted over gestation, implying that cells with high differentiation potential may be isolated at the end of pregnancy. In conclusion, this study suggests that cells with highest stem cell characteristics may originate from the fetus itself or the amniotic fetal adnexa rather than from the efferent urinary tract or the allantoic fetal adnexa.

Solid catalyzed isoparaffin alkylation at supercritical fluid and near-supercritical fluid conditions

Science.gov (United States)

Ginosar, Daniel M.; Fox, Robert V.; Kong, Peter C.

2000-01-01

This invention relates to an improved method for the alkylation reaction of isoparaffins with olefins over solid catalysts including contacting a mixture of an isoparaffin, an olefin and a phase-modifying material with a solid acid catalyst member under alkylation conversion conditions at either supercritical fluid, or near-supercritical fluid conditions, at a temperature and a pressure relative to the critical temperature(T.sub.c) and the critical pressure(P.sub.c) of the reaction mixture. The phase-modifying phase-modifying material is employed to promote the reaction's achievement of either a supercritical fluid state or a near-supercritical state while simultaneously allowing for decreased reaction temperature and longer catalyst life.

Aviator's Fluid Balance During Military Flight.

Science.gov (United States)

Levkovsky, Anna; Abot-Barkan, Sivan; Chapnik, Leah; Doron, Omer; Levy, Yuval; Heled, Yuval; Gordon, Barak

2018-02-01

A loss of 1% or more of bodyweight due to dehydration has a negative effect on cognitive performance, which could critically affect flight safety. There is no mention in the literature concerning the amounts of military pilots' fluid loss during flight. The aim of this study was to quantify fluid loss of pilots during military flight. There were 48 aviators (mean age 23.9) from the Israeli Air Force who participated in the study, which included 104 training flights in various flight platforms. Bodyweight, urine specific gravity, and environmental heat strain were measured before and after each flight. Fluid loss was calculated as the weight differences before and after the flight. We used a univariate and one-way ANOVA to analyze the effect of different variables on the fluid loss. The mean fluid loss rate was 462 ml · h-1. The results varied among different aircraft platforms and depended on flight duration. Blackhawk pilots lost the highest amount of fluids per flight, albeit had longer flights (mean 108 min compared to 35.5 in fighter jets). Jet fighter pilots had the highest rate of fluid loss per hour of flight (up to 692 ml, extrapolated). Overall, at 11 flights (11%) aircrew completed their flight with a meaningful fluid loss. We conclude that military flights may be associated with significant amount of fluid loss among aircrew.Levkovsky A, Abot-Barkan S, Chapnik L, Doron O, Levy Y, Heled Y, Gordon B. Aviator's fluid balance during military flight. Aerosp Med Hum Perform. 2018; 89(2):9498.

Superconfinement tailors fluid flow at microscales.

KAUST Repository

Setu, Siti Aminah; Dullens, Roel P A; Herná ndez-Machado, Aurora; Pagonabarraga, Ignacio; Aarts, Dirk G A L; Ledesma-Aguilar, Rodrigo

2015-01-01

Understanding fluid dynamics under extreme confinement, where device and intrinsic fluid length scales become comparable, is essential to successfully develop the coming generations of fluidic devices. Here we report measurements of advancing fluid

Self-lubricating fluid bearing assembly

International Nuclear Information System (INIS)

Kapich, D.D.

1981-01-01

A sealed self-lubricating fluid bearing assembly is described for circulating fluid in the form of a gas coolant in a nuclear reactor, the power for the circulator being provided by a shaft located within the primary containment vessel. In such a system the reactor coolant is isolated from the fluid region at the far end of the drive shaft. (U.K.)

Hydrodynamic bearing lubricated with magnetic fluids

International Nuclear Information System (INIS)

Urreta, H; Leicht, Z; Sanchez, A; Agirre, A; Kuzhir, P; Magnac, G

2009-01-01

This paper summarizes the work carried out in the development of hydrodynamic lubricated journal bearings with magnetic fluids. Two different fluids have been analyzed, one ferrofluid from FERROTEC APG s10n and one magnetorheological fluid from LORD Corp., MRF122-2ED. Theoretical analysis has been carried out with numerical solutions of Reynolds equation, based on apparent viscosity modulation for ferrofluid and Bingham model for MR fluid. To validate this model, one test bench has been designed, manufactured and set up, where preliminary results shown in this paper demonstrate that magnetic fluids can be used to develop active journal bearings.

Nonlinear transport processes and fluid dynamics: Cylindrical Couette flow of Lennard-Jones fluids

International Nuclear Information System (INIS)

Khayat, R.E.; Eu, B.C.

1988-01-01

In this paper we report on calculations of flow profiles for cylindrical Couette flow of a Lennard-Jones fluid. The flow is subjected to a temperature gradient and thermoviscous effects are taken into consideration. We apply the generalized fluid dynamic equations which are provided by the modified moment method for the Boltzmann equation reported previously. The results of calculations are in good agreement with the Monte Carlo direct simulation method by K. Nanbu [Phys. Fluids 27, 2632 (1984)] for most of Knudsen numbers for which the simulation data are available

CRITICALITY CURVES FOR PLUTONIUM HYDRAULIC FLUID MIXTURES

International Nuclear Information System (INIS)

WITTEKIND WD

2007-01-01

This Calculation Note performs and documents MCNP criticality calculations for plutonium (100% 239 Pu) hydraulic fluid mixtures. Spherical geometry was used for these generalized criticality safety calculations and three geometries of neutron reflection are: (sm b ullet)bare, (sm b ullet)1 inch of hydraulic fluid, or (sm b ullet)12 inches of hydraulic fluid. This document shows the critical volume and critical mass for various concentrations of plutonium in hydraulic fluid. Between 1 and 2 gallons of hydraulic fluid were discovered in the bottom of HA-23S. This HA-23S hydraulic fluid was reported by engineering to be Fyrquel 220. The hydraulic fluid in GLovebox HA-23S is Fyrquel 220 which contains phosphorus. Critical spherical geometry in air is calculated with 0 in., 1 in., or 12 inches hydraulic fluid reflection

SPH modeling of fluid-solid interaction for dynamic failure analysis of fluid-filled thin shells

Science.gov (United States)

Caleyron, F.; Combescure, A.; Faucher, V.; Potapov, S.

2013-05-01

This work concerns the prediction of failure of a fluid-filled tank under impact loading, including the resulting fluid leakage. A water-filled steel cylinder associated with a piston is impacted by a mass falling at a prescribed velocity. The cylinder is closed at its base by an aluminum plate whose characteristics are allowed to vary. The impact on the piston creates a pressure wave in the fluid which is responsible for the deformation of the plate and, possibly, the propagation of cracks. The structural part of the problem is modeled using Mindlin-Reissner finite elements (FE) and Smoothed Particle Hydrodynamics (SPH) shells. The modeling of the fluid is also based on an SPH formulation. The problem involves significant fluid-structure interactions (FSI) which are handled through a master-slave-based method and the pinballs method. Numerical results are compared to experimental data.

Principles of fluid-structure interaction

International Nuclear Information System (INIS)

Schumann, U.; Kernforschungszentrum Karlsruhe G.m.b.H.

1981-01-01

Fluid-structure interaction (FSI) is an important physical phenomenon which has attracted significant attention in nuclear reactor safety analysis. Here, simple explanations of the principle effects of FSI are given and illustrated by reference to numerical and experimental results. First, a very simple fluid-structure model is introduced which consists of a spring supported piston closing a fluid filled rigid pipe. The motion of the piston and the fluid is approximately described by one degree of freedom, respectively. Depending on the load frequency and material parameters one finds that the coupled system is characterized by virtual masses and stiffnesses or by the inverse properties which are termed virtual fluidities and compressibilities. Thus the two parts interact as if they are connected in series or in parallel. The two eigenfrequencies of the coupled system enclose the eigenfrequencies of the individual fluid and structure parts. Second, the great importance of Hamilton's principle for derivation of the coupled equations of motion is emphasized. From this principle upper and lower bounds for the effective density of a heterogeneous fluid-solid mixture are deduced. Continuum models for such mixtures contain a virtual density tensor. Finally, we discuss FSI for the case of a loss-of-coolant accident (LOCA) in a pressurized water reactor (PWR) in the first (subcooled) blowdown period. Here, the fluid imposes pressure loadings on internal structures like the core barrel and the motion of these structures influences the fluid motion. Recent experimental results obtained at the HDR are compared with numerical predictions of the FLUX 2-code. The fair agreement confirms that we have well understood the principal effects of FSI. (orig.) [de

Effect of fluid friction on interstitial fluid flow coupled with blood flow through solid tumor microvascular network.

Science.gov (United States)

Sefidgar, Mostafa; Soltani, M; Raahemifar, Kaamran; Bazmara, Hossein

2015-01-01

A solid tumor is investigated as porous media for fluid flow simulation. Most of the studies use Darcy model for porous media. In Darcy model, the fluid friction is neglected and a few simplified assumptions are implemented. In this study, the effect of these assumptions is studied by considering Brinkman model. A multiscale mathematical method which calculates fluid flow to a solid tumor is used in this study to investigate how neglecting fluid friction affects the solid tumor simulation. The mathematical method involves processes such as blood flow through vessels and solute and fluid diffusion, convective transport in extracellular matrix, and extravasation from blood vessels. The sprouting angiogenesis model is used for generating capillary network and then fluid flow governing equations are implemented to calculate blood flow through the tumor-induced capillary network. Finally, the two models of porous media are used for modeling fluid flow in normal and tumor tissues in three different shapes of tumors. Simulations of interstitial fluid transport in a solid tumor demonstrate that the simplifications used in Darcy model affect the interstitial velocity and Brinkman model predicts a lower value for interstitial velocity than the values that Darcy model predicts.

Fluid diversion in oil recovery

International Nuclear Information System (INIS)

Nimir, Hassan B.

1999-01-01

In any oil recovery process, large scale heterogeneities, such as fractures, channels, or high-permeability streaks, can cause early break through of injected fluid which will reduce oil recovery efficiency. In waterflooding, enhanced oil recovery, and acidizing operations, this problem is particularly acute because of the cost of the injected fluid. On the other hand coping with excess water production is always a challenging task for field operators. The cost of handling and disposing produced water can significantly shorten the economic production life of an oil well. The hydrostatic pressure created by high fluid levels in a well (water coning) is also detrimental to oil production. In this paper, the concept of fluid diversion is explained. Different methods that are suggested to divert the fluid into the oil-bearing-zones are briefly discussed, to show their advantages and disadvantages. Methods of reducing water production in production well are also discussed. (Author)

Revisiting the Landau fluid closure.

Science.gov (United States)

Hunana, P.; Zank, G. P.; Webb, G. M.; Adhikari, L.

2017-12-01

Advanced fluid models that are much closer to the full kinetic description than the usual magnetohydrodynamic description are a very useful tool for studying astrophysical plasmas and for interpreting solar wind observational data. The development of advanced fluid models that contain certain kinetic effects is complicated and has attracted much attention over the past years. Here we focus on fluid models that incorporate the simplest possible forms of Landau damping, derived from linear kinetic theory expanded about a leading-order (gyrotropic) bi-Maxwellian distribution function f_0, under the approximation that the perturbed distribution function f_1 is gyrotropic as well. Specifically, we focus on various Pade approximants to the usual plasma response function (and to the plasma dispersion function) and examine possibilities that lead to a closure of the linear kinetic hierarchy of fluid moments. We present re-examination of the simplest Landau fluid closures.

CISM Course on Rotating Fluids

CERN Document Server

1992-01-01

The volume presents a comprehensive overview of rotation effects on fluid behavior, emphasizing non-linear processes. The subject is introduced by giving a range of examples of rotating fluids encountered in geophysics and engineering. This is then followed by a discussion of the relevant scales and parameters of rotating flow, and an introduction to geostrophic balance and vorticity concepts. There are few books on rotating fluids and this volume is, therefore, a welcome addition. It is the first volume which contains a unified view of turbulence in rotating fluids, instability and vortex dynamics. Some aspects of wave motions covered here are not found elsewhere.

Higher-dimensional relativistic-fluid spheres

International Nuclear Information System (INIS)

Patel, L. K.; Ahmedabad, Gujarat Univ.

1997-01-01

They consider the hydrostatic equilibrium of relativistic-fluid spheres for a D-dimensional space-time. Three physically viable interior solutions of the Einstein field equations corresponding to perfect-fluid spheres in a D-dimensional space-time are obtained. When D = 4 they reduce to the Tolman IV solution, the Mehra solution and the Finch-Skea solution. The solutions are smoothly matched with the D-dimensional Schwarzschild exterior solution at the boundary r = a of the fluid sphere. Some physical features and other related details of the solutions are briefly discussed. A brief description of two other new solutions for higher-dimensional perfect-fluid spheres is also given

Growth kinetics in multicomponent fluids

International Nuclear Information System (INIS)

Chen, S.; Lookman, T.

1995-01-01

The hydrodynamic effects on the late-stage kinetics in spinodal decomposition of multicomponent fluids are examined using a lattice Boltzmann scheme with stochastic fluctuations in the fluid and at the interface. In two dimensions, the three- and four-component immiscible fluid mixture (with a 1024 2 lattice) behaves like an off-critical binary fluid with an estimated domain growth of t 0.4 +/= 0.03 rather than t 1/3 as previously estimated, showing the significant influence of hydrodynamics. In three dimensions (with a 256 3 lattice), we estimate the growth as t 0.96 +/= 0.05 for both critical and off-critical quenches, in agreement with phenomenological theory

Fluid Annotations in a Open World

DEFF Research Database (Denmark)

Zellweger, Polle Trescott; Bouvin, Niels Olof; Jehøj, Henning

2001-01-01

Fluid Documents use animated typographical changes to provide a novel and appealing user experience for hypertext browsing and for viewing document annotations in context. This paper describes an effort to broaden the utility of Fluid Documents by using the open hypermedia Arakne Environment to l...... to layer fluid annotations and links on top of abitrary HTML pages on the World Wide Web. Changes to both Fluid Documents and Arakne are required....

Supercritical fluids processing: emerging opportunities

International Nuclear Information System (INIS)

Kovaly, K.A.

1985-01-01

This publication on the emerging opportunities of supercritical fluids processing reveals the latest research findings and development trends in this field. These findings and development trends are highlighted, and the results of applications of technology to the business of supercritical fluids are reported. Applications of supercritical fluids to chemical intermediates, environmental applications, chemical reactions, food and biochemistry processing, and fuels processing are discussed in some detail

Review of computational fluid dynamics (CFD) researches on nano fluid flow through micro channel

Science.gov (United States)

Dewangan, Satish Kumar

2018-05-01

Nanofluid is becoming a promising heat transfer fluids due to its improved thermo-physical properties and heat transfer performance. Micro channel heat transfer has potential application in the cooling high power density microchips in CPU system, micro power systems and many such miniature thermal systems which need advanced cooling capacity. Use of nanofluids enhances the effectiveness of t=scu systems. Computational Fluid Dynamics (CFD) is a very powerful tool in computational analysis of the various physical processes. It application to the situations of flow and heat transfer analysis of the nano fluids is catching up very fast. Present research paper gives a brief account of the methodology of the CFD and also summarizes its application on nano fluid and heat transfer for microchannel cases.

MR imaging of a malignant schwannoma and an osteoblastoma with fluid-fluid levels. Report of two new cases

International Nuclear Information System (INIS)

Vilanova, J.C.; Dolz, J.L.; Aldoma, J.; Capdevila, A.; Maestro de Leon, J.L.; Aparicio, A.

1998-01-01

One case of malignant schwannoma of the sacrum and another of occipital osteoblastoma were evaluated by MR imaging. Both tumors showed fluid-fluid levels with different signal intensities in the sequences performed. Pathologic examination revealed hemmorhagic fluid in both tumors. Malignant schwannoma and osteoblastoma should be included in the list of bone and soft-tissue with fluid-fluid levels. Our data confirm the non-specificity of this finding, which only suggests the presence of previous intratumoral hemorrhage. (orig.) (orig.)

Boiler using combustible fluid

Science.gov (United States)

Baumgartner, H.; Meier, J.G.

1974-07-03

A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

Adrenal hormones in human follicular fluid.

Science.gov (United States)

Jimena, P; Castilla, J A; Peran, F; Ramirez, J P; Vergara, F; Molina, R; Vergara, F; Herruzo, A

1992-11-01

Considerable evidence indicates that adrenal hormones may affect gonadal function. To assess the role of some adrenal hormones in human follicular fluid and their relationship with the ability of the oocyte to be fertilized and then to cleave in vitro, cortisol and dehydroepiandrosterone sulfate were measured in follicular fluid obtained at the time of oocyte recovery for in vitro fertilization from cycles stimulated by clomiphene citrate, human menopausal gonadotropin and human chorionic gonadotropin. Thirty-six follicular fluid containing mature oocyte-corona-cumulus complexes and free of visible blood contamination were included in this study. There was no significant difference in follicular fluid dehydroepiandrosterone sulfate concentration between follicles with oocytes which did or did not fertilize (5.1 +/- 1.1 vs 5.8 +/- 2.0 mumol/l). However, follicular fluid from follicles whose oocytes were not fertilized had levels of cortisol significantly higher than those in follicular fluid from follicles containing successfully fertilized oocytes (406.0 +/- 75.9 vs 339.2 +/- 37.0 nmol/l; p < 0.005). No significant correlations were found between rates of embryo cleavage and cortisol and dehydroepiandrosterone levels in follicular fluid. We conclude that cortisol levels in follicular fluid may provide an index of fertilization outcome, at least in stimulated cycles by clomiphene citrate, human menopausal gonadotropin and human chorionic gonadotropin.

Spreading dynamics of power-law fluid droplets

International Nuclear Information System (INIS)

Liang Zhanpeng; Peng Xiaofeng; Wang Xiaodong; Lee, D-J; Su Ay

2009-01-01

This paper aims at providing a summary of the theoretical models available for non-Newtonian fluid spreading dynamics. Experimental findings and model predictions for a Newtonian fluid spreading test are briefly reviewed. Then how the complete wetting and partial wetting power-law fluids spread over a solid substrate is examined. The possible extension of Newtonian fluid models to power-law fluids is also discussed.

Resolution of through tubing fluid flow and behind casing fluid flow in multiple completion wells

International Nuclear Information System (INIS)

Arnold, D.M.

1977-01-01

A method is provided for resolving undesired fluid flow in cement channels behind casing in one producing zone of a multi zone completion well operating on gas lift from the fluid flow from lower producing zones in the same well which is contained in production tubing passing through the producing zone being investigated. Gamma rays which are characteristic of the decay of the unstable isotope nitrogen 16 produced by activation of elemental oxygen nuclei comprising the molecular structure of both the tubing fluid flow and the undesired fluid flow are detected in at least two energy bonds at two longitudinally spaced detectors in a well borehole. By appropriately combining the four count rate signals so producing according to predetermined relationships the two fluid flow components in the same direction may be uniquely distinguished on the basis of their differing distances from the gamma ray detectors. 9 claims, 17 figures

Cryogenic Fluid Management Facility

Science.gov (United States)

Eberhardt, R. N.; Bailey, W. J.

1985-01-01

The Cryogenic Fluid Management Facility is a reusable test bed which is designed to be carried within the Shuttle cargo bay to investigate the systems and technologies associated with the efficient management of cryogens in space. Cryogenic fluid management consists of the systems and technologies for: (1) liquid storage and supply, including capillary acquisition/expulsion systems which provide single-phase liquid to the user system, (2) both passive and active thermal control systems, and (3) fluid transfer/resupply systems, including transfer lines and receiver tanks. The facility contains a storage and supply tank, a transfer line and a receiver tank, configured to provide low-g verification of fluid and thermal models of cryogenic storage and transfer processes. The facility will provide design data and criteria for future subcritical cryogenic storage and transfer system applications, such as Space Station life support, attitude control, power and fuel depot supply, resupply tankers, external tank (ET) propellant scavenging, and ground-based and space-based orbit transfer vehicles (OTV).

XXII Fluid Mechanics Conference (KKMP2016)

International Nuclear Information System (INIS)

2016-01-01

This Journal of Physics: Conference Series contains papers that have been presented at XXII Fluid Mechanics Conference (XXII FMC) held in Słok near Bełchatów in Poland during llth-14th September of 2016. The Conference is organized by Wrocław University of Science and Technology, Polish Academy of Sciences - Committee of Mechanics and Foun-dation for Development of Wroclaw University of Science and Technology. Let us recall some historical facts: Fluid Mechanics Conferences have been taking place every two years since 1974, which makes a total of forty-two years. The goal of this conference is to provide a forum for exposure and exchange of ideas, methods and results in fluid mechanics. We have already met in Bełchatów 10 years ago (XVII KKMP). It was a successful meeting. Since then the National Conference on Fluid Mechanics has changed title and has started to be named Fluid Mechanics Conference in the hopes that it will attract more participants from other countries. English became the Conference's first language and we started to invite world leading scientists - working in the field of fluid mechanics. At the 2006 conference we hosted for the first time prof. Keith Moffatt from the Cambridge University. In this year prof. Moffatt once again promised us to arrive to Bełchatów. The whole fluid mechanics community celebrates 9 2 anniversary of his birthday. So let us also wish happy anniversary to prof. Moffatt. In the mean time we had to pay last respects to our collages. Prof. Prosnak who is regarded as a founder of the Notational Conference on Fluid Mechanics and is well known through his books. Prof. Puzyrewski who was present at all conferences so far. He was providing via his discussions a special value to these conferences, and our colleague prof. Konrad Bajer who was intended to be the organizer and host of the present conference. Short memories to them will be given during the opening ceremony. Conference topics include, but are not limited

Advances in fluid modeling and turbulence measurements

International Nuclear Information System (INIS)

Wada, Akira; Ninokata, Hisashi; Tanaka, Nobukazu

2002-01-01

The context of this book consists of four fields: Environmental Fluid Mechanics; Industrial Fluid Mechanics; Fundamentals of Fluid Mechanics; and Turbulence Measurements. Environmental Fluid Mechanics includes free surface flows in channels, rivers, seas, and estuaries. It also discusses wind engineering issues, ocean circulation model and dispersion problems in atmospheric, water and ground water environments. In Industrial Fluid Mechanics, fluid phenomena in energy exchanges, modeling of turbulent two- or multi-phase flows, swirling flows, flows in combustors, variable density flows and reacting flows, flows in turbo-machines, pumps and piping systems, and fluid-structure interaction are discussed. In Fundamentals of Fluid Mechanics, progress in modeling turbulent flows and heat/mass transfers, computational fluid dynamics/numerical techniques, parallel computing algorithms, applications of chaos/fractal theory in turbulence are reported. In Turbulence Measurements, experimental studies of turbulent flows, experimental and post-processing techniques, quantitative and qualitative flow visualization techniques are discussed. Separate abstracts were presented for 15 of the papers in this issue. The remaining 89 were considered outside the subject scope of INIS. (J.P.N.)

Generating perfect fluid spheres in general relativity

Science.gov (United States)

Boonserm, Petarpa; Visser, Matt; Weinfurtner, Silke

2005-06-01

Ever since Karl Schwarzschild’s 1916 discovery of the spacetime geometry describing the interior of a particular idealized general relativistic star—a static spherically symmetric blob of fluid with position-independent density—the general relativity community has continued to devote considerable time and energy to understanding the general-relativistic static perfect fluid sphere. Over the last 90 years a tangle of specific perfect fluid spheres has been discovered, with most of these specific examples seemingly independent from each other. To bring some order to this collection, in this article we develop several new transformation theorems that map perfect fluid spheres into perfect fluid spheres. These transformation theorems sometimes lead to unexpected connections between previously known perfect fluid spheres, sometimes lead to new previously unknown perfect fluid spheres, and in general can be used to develop a systematic way of classifying the set of all perfect fluid spheres.

Generating perfect fluid spheres in general relativity

International Nuclear Information System (INIS)

Boonserm, Petarpa; Visser, Matt; Weinfurtner, Silke

2005-01-01

Ever since Karl Schwarzschild's 1916 discovery of the spacetime geometry describing the interior of a particular idealized general relativistic star--a static spherically symmetric blob of fluid with position-independent density--the general relativity community has continued to devote considerable time and energy to understanding the general-relativistic static perfect fluid sphere. Over the last 90 years a tangle of specific perfect fluid spheres has been discovered, with most of these specific examples seemingly independent from each other. To bring some order to this collection, in this article we develop several new transformation theorems that map perfect fluid spheres into perfect fluid spheres. These transformation theorems sometimes lead to unexpected connections between previously known perfect fluid spheres, sometimes lead to new previously unknown perfect fluid spheres, and in general can be used to develop a systematic way of classifying the set of all perfect fluid spheres

Mass transfer in nano-fluids: A review

International Nuclear Information System (INIS)

Ashrafmansouri, Seyedeh-Saba; Esfahany, Mohsen Nasr

2014-01-01

Growing attention has been recently paid to nano-fluids because of their potential for augmenting transfer processes - i.e., heat and mass transfer. Conflicting results have been reported in the literature on mass transfer in nano-fluids. The aim of this paper is to summarize the literature on mass transfer in nano-fluids stating the conflicts and possible reasons. Literature on mass transfer in nano-fluids has been reviewed in two sections. The first section concentrates on surveying mass diffusivity in nano-fluids while the second section focuses on convective mass transfer in nano-fluids. In each section, published articles, type of nano-fluids used, size and concentration range of nanoparticles, measurement methods, maximum observed enhancement, and suggested mass transport mechanisms are summarized. (authors)

Proceedings of industrial applications of fluid mechanics

International Nuclear Information System (INIS)

Sherif, S.A.; Morrow, T.B.; Marshall, L.R.; Dalton, C.

1990-01-01

The is the fourth Forum on Industrial Applications of Fluid Mechanics sponsored by the Fluid Mechanics Committee of the ASME Fluids Engineering Division. The Forum objective is to promote the discussion and interchange of current information on developing and state-of-the-art applications of fluid mechanics technology. The program is organized as a technical forum to encourage the presentation of new ideas, especially those which may be so innovative that a conservative review process might delay their dissemination to the fluids engineering community. Four sessions and a total of 17 papers are scheduled for this program. Three of the four sessions were devoted to contributed papers, while the fourth is a panel discussion with three invited presentations. All papers were reviewed editorially to assure that they are related to the forum theme The papers were not evaluated technically, and therefore carry no endorsement from the Fluid Mechanics Committee or the Fluids Engineering Division with regard to peer evaluation. The forum presentations will focus on specific applications of fluid mechanics technology. Lively discussion of the papers is encouraged at the forum. The Fluid Mechanics Committee plans to sponsor a forum with an industrial applications theme each year at the ASME Winter Annual Meeting. In 1991, the scope of the forum will be enlarged to include the topic of textile applications of fluid mechanics, and another panel session featuring speakers with industrial experience in different areas of fluid mechanics applications. In future years, it is anticipated that the forum will solicit papers from other areas where fluid mechanics technology is applied

Numerical investigation of fluid mud motion using a three-dimensional hydrodynamic and two-dimensional fluid mud coupling model

Science.gov (United States)

Yang, Xiaochen; Zhang, Qinghe; Hao, Linnan

2015-03-01

A water-fluid mud coupling model is developed based on the unstructured grid finite volume coastal ocean model (FVCOM) to investigate the fluid mud motion. The hydrodynamics and sediment transport of the overlying water column are solved using the original three-dimensional ocean model. A horizontal two-dimensional fluid mud model is integrated into the FVCOM model to simulate the underlying fluid mud flow. The fluid mud interacts with the water column through the sediment flux, current, and shear stress. The friction factor between the fluid mud and the bed, which is traditionally determined empirically, is derived with the assumption that the vertical distribution of shear stress below the yield surface of fluid mud is identical to that of uniform laminar flow of Newtonian fluid in the open channel. The model is validated by experimental data and reasonable agreement is found. Compared with numerical cases with fixed friction factors, the results simulated with the derived friction factor exhibit the best agreement with the experiment, which demonstrates the necessity of the derivation of the friction factor.

Pressure–Temperature–Fluid Constraints for the Poona Emerald Deposits, Western Australia: Fluid Inclusion and Stable Isotope Studies

Directory of Open Access Journals (Sweden)

Dan Marshall

2016-12-01

Full Text Available Emerald from the deposits at Poona shows micrometre-scale chemical, optical, and cathodoluminescence zonation. This zonation, combined with fluid inclusion and isotope studies, indicates early emerald precipitation from a single-phase saline fluid of approximately 12 weight percent NaCl equivalent, over the temperature range of 335–525 °C and pressures ranging from 70 to 400 MPa. The large range in pressure and temperature likely reflects some post entrapment changes and re-equilibration of oxygen isotopes. Secondary emerald-hosted fluid inclusions indicate subsequent emerald precipitation from higher salinity fluids. Likewise, the δ18O-δD of channel fluids extracted from Poona emerald is consistent with multiple origins yielding both igneous and metamorphic signatures. The combined multiple generations of emerald precipitation, different fluid compositions, and the presence of both metamorphic and igneous fluids trapped in emerald, likely indicate a protracted history of emerald precipitation at Poona conforming to both an igneous and a metamorphic origin at various times during regional lower amphibolite to greenschist facies metamorphism over the period ~2710–2660 Ma.

Clay-based geothermal drilling fluids

Energy Technology Data Exchange (ETDEWEB)

Guven, N.; Carney, L.L.; Lee, L.J.; Bernhard, R.P.

1982-11-01

The rheological properties of fluids based on fibrous clays such as sepiolite and attapulgite have been systematically examined under conditions similar to those of geothermal wells, i.e. at elevated temperatures and pressures in environments with concentrated brines. Attapulgite- and sepiolite-based fluids have been autoclaved at temperatures in the range from 70 to 800/sup 0/F with the addition of chlorides and hydroxides of Na, K, Ca, and Mg. The rheological properties (apparent and plastic viscosity, fluid loss, gel strength, yield point, and cake thickness) of the autoclaved fluids have been studied and correlated with the chemical and physical changes that occur in the clay minerals during the autoclaving process.

MR imaging of a malignant schwannoma and an osteoblastoma with fluid-fluid levels. Report of two new cases

Energy Technology Data Exchange (ETDEWEB)

Vilanova, J.C.; Dolz, J.L.; Aldoma, J.; Capdevila, A. [Centre Diagnostic Pedralbes, Ressonancia Magnetica, Barcelona (Spain); Maestro de Leon, J.L.; Aparicio, A. [Department of Neurosurgery, Hospital Mutua de Terrassa, Barcelona (Spain)

1998-10-01

One case of malignant schwannoma of the sacrum and another of occipital osteoblastoma were evaluated by MR imaging. Both tumors showed fluid-fluid levels with different signal intensities in the sequences performed. Pathologic examination revealed hemmorhagic fluid in both tumors. Malignant schwannoma and osteoblastoma should be included in the list of bone and soft-tissue with fluid-fluid levels. Our data confirm the non-specificity of this finding, which only suggests the presence of previous intratumoral hemorrhage. (orig.) (orig.) With 2 figs., 2 tabs., 17 refs.

Particles at fluid-fluid interfaces: A new Navier-Stokes-Cahn-Hilliard surface- phase-field-crystal model.

Science.gov (United States)

Aland, Sebastian; Lowengrub, John; Voigt, Axel

2012-10-01

Colloid particles that are partially wetted by two immiscible fluids can become confined to fluid-fluid interfaces. At sufficiently high volume fractions, the colloids may jam and the interface may crystallize. The fluids together with the interfacial colloids form an emulsion with interesting material properties and offer an important route to new soft materials. A promising approach to simulate these emulsions was presented in Aland et al. [Phys. Fluids 23, 062103 (2011)], where a Navier-Stokes-Cahn-Hilliard model for the macroscopic two-phase fluid system was combined with a surface phase-field-crystal model for the microscopic colloidal particles along the interface. Unfortunately this model leads to spurious velocities which require very fine spatial and temporal resolutions to accurately and stably simulate. In this paper we develop an improved Navier-Stokes-Cahn-Hilliard-surface phase-field-crystal model based on the principles of mass conservation and thermodynamic consistency. To validate our approach, we derive a sharp interface model and show agreement with the improved diffuse interface model. Using simple flow configurations, we show that the new model has much better properties and does not lead to spurious velocities. Finally, we demonstrate the solid-like behavior of the crystallized interface by simulating the fall of a solid ball through a colloid-laden multiphase fluid.

Fluid dynamics theoretical and computational approaches

CERN Document Server

Warsi, ZUA

2005-01-01

Important Nomenclature Kinematics of Fluid Motion Introduction to Continuum Motion Fluid Particles Inertial Coordinate Frames Motion of a Continuum The Time Derivatives Velocity and Acceleration Steady and Nonsteady Flow Trajectories of Fluid Particles and Streamlines Material Volume and Surface Relation between Elemental Volumes Kinematic Formulas of Euler and Reynolds Control Volume and Surface Kinematics of Deformation Kinematics of Vorticity and Circulation References Problems The Conservation Laws and the Kinetics of Flow Fluid Density and the Conservation of Mass Prin

Flow modelling of a newtonian fluid by two regions- the region of pure fluid and porous region

International Nuclear Information System (INIS)

Sampaio, R.; Gama, R.M.S. da

1983-01-01

A model of flow with two regions is presented using mixture theory. One region contains only pure fluid and the other a mixture of fluid and porous rigid solid. Compatibility conditons on the pure fluid-mixture interface are carefully discussed. The theory is used to solve a problem of a flow induced by pressure gradient and helicoidal motion of an impermeable cylinder on two rings one of pure fluid and another of mixture. (Author) [pt

Fluid mechanics in the perivascular space.

Science.gov (United States)

Wang, Peng; Olbricht, William L

2011-04-07

Perivascular space (PVS) within the brain is an important pathway for interstitial fluid (ISF) and solute transport. Fluid flowing in the PVS can affect these transport processes and has significant impacts on physiology. In this paper, we carry out a theoretical analysis to investigate the fluid mechanics in the PVS. With certain assumptions and approximations, we are able to find an analytical solution to the problem. We discuss the physical meanings of the solution and particularly examine the consequences of the induced fluid flow in the context of convection-enhanced delivery (CED). We conclude that peristaltic motions of the blood vessel walls can facilitate fluid and solute transport in the PVS. Copyright © 2011 Elsevier Ltd. All rights reserved.

Nonlinear rheology of complex fluid-fluid interfaces

NARCIS (Netherlands)

Sagis, L.M.C.; Fischer, P.

2014-01-01

Fluid–fluid interfaces stabilized by proteins, protein aggregates, polymers, or colloidal particles, tend to have a complex microstructure. Their response to an applied deformation is often highly nonlinear, even at small deformation (rates). The nonlinearity of the response is a result of changes

Diagnostic imaging of small amounts of pleural fluid: pleural effusion vs. physiologic pleural fluid.

Science.gov (United States)

Kocijancic, Igor

2007-12-01

The aim of this article is to present an overview of our 10 years clinical research work and early clinical experience with small pleural effusions. Small amounts of pleural fluid are severely difficult to identify with imaging methods (chest x-rays and ultrasound). Nevertheless, it may be an important finding, sometimes leading to a definitive diagnosis of pleural carcinomatosis, infection or other pathologic condition. Chest x-rays were used for many years for the diagnosis of small pleural effusions. Lateral decubitus chest radiographs represented a gold standard for imaging of small amounts of plural fluid for more than 80 years. In the last two decades, ultrasonography of pleural space became a leading real-time method for demonstrating small pleural effusions. Furthermore, the advent of sonographic technology actually enables detection of physiologic pleural fluid in some otherwise healthy individuals. In conclusion, new definitions of the key terms in the field of diagnostic imaging of small amounts of pleural fluid seem to be justified. We suggest that the term pleural fluid should determine physiologic pleural space condition while the term pleural effusion should only be used in the cases of pleural involvement or pleural illness.

Prolonged effect of fluid flow stress on the proliferative activity of mesothelial cells after abrupt discontinuation of fluid streaming

International Nuclear Information System (INIS)

Aoki, Shigehisa; Ikeda, Satoshi; Takezawa, Toshiaki; Kishi, Tomoya; Makino, Junichi; Uchihashi, Kazuyoshi; Matsunobu, Aki; Noguchi, Mitsuru; Sugihara, Hajime; Toda, Shuji

2011-01-01

Highlights: ► Late-onset peritoneal fibrosis leading to EPS remains to be elucidated. ► Fluid streaming is a potent factor for peritoneal fibrosis in PD. ► We focused on the prolonged effect of fluid streaming on mesothelial cell kinetics. ► A history of fluid streaming exposure promoted mesothelial proliferative activity. ► We have thus identified a potent new factor for late-onset peritoneal fibrosis. -- Abstract: Encapsulating peritoneal sclerosis (EPS) often develops after transfer to hemodialysis and transplantation. Both termination of peritoneal dialysis (PD) and transplantation-related factors are risks implicated in post-PD development of EPS, but the precise mechanism of this late-onset peritoneal fibrosis remains to be elucidated. We previously demonstrated that fluid flow stress induced mesothelial proliferation and epithelial–mesenchymal transition via mitogen-activated protein kinase (MAPK) signaling. Therefore, we speculated that the prolonged bioactive effect of fluid flow stress may affect mesothelial cell kinetics after cessation of fluid streaming. To investigate how long mesothelial cells stay under the bioactive effect brought on by fluid flow stress after removal of the stress, we initially cultured mesothelial cells under fluid flow stress and then cultured the cells under static conditions. Mesothelial cells exposed to fluid flow stress for a certain time showed significantly high proliferative activity compared with static conditions after stoppage of fluid streaming. The expression levels of protein phosphatase 2A, which dephosphorylates MAPK, in mesothelial cells changed with time and showed a biphasic pattern that was dependent on the duration of exposure to fluid flow stress. There were no differences in the fluid flow stress-related bioactive effects on mesothelial cells once a certain time had passed. The present findings show that fluid flow stress exerts a prolonged bioactive effect on mesothelial cells after termination

Effects of fluid communications between fluid volumes on the seismic behaviour of nuclear breeder reactor internals

International Nuclear Information System (INIS)

Durandet, E.; Gibert, R.J.

1987-01-01

The internal structures of a breeder reactor as SUPERPHENIX are mainly axisymmetrial shells separated by fluid volumes which are connected by small communications holes. These communications can destroy the axisymmetry of the problem and their effects on the inertial terms due to the fluid are important. An equivalent axisymmetrical element based on a local tridimensional solution in the vicinity of the fluid communication is defined. An axisymmetrical modelization using this type of element is built in order to calculate the horizontal seismic behaviour of the reactor internals. The effect due to three typical fluid communications are studied and compared. (orig.)

EXPERIMENTAL STUDY OF MAGNETIC FLUID SEAL

Directory of Open Access Journals (Sweden)

V. G. Bashtovoi

2006-01-01

Full Text Available Dependences of critical pressure drop, being held by magnetic fluid seal, on time in a static state and shaft rotation velocity in dynamics have been experimentally determined. The significant influence of particles’ redistribution in magnetic fluid on static parameters of magnetic fluid seal has been established.

An introduction to Computational Fluid Dynamics

DEFF Research Database (Denmark)

Sørensen, Lars Schiøtt

1999-01-01

CFD is the shortname for Computational Fluid Dynamics and is a numerical method by means of which we can analyze systems containing fluids. For instance systems dealing with heat flow or smoke control systems acting when a fire occur in a building.......CFD is the shortname for Computational Fluid Dynamics and is a numerical method by means of which we can analyze systems containing fluids. For instance systems dealing with heat flow or smoke control systems acting when a fire occur in a building....

Introduction to thermo-fluids systems design

CERN Document Server

Garcia McDonald, André

2012-01-01

A fully comprehensive guide to thermal systems design covering fluid dynamics, thermodynamics, heat transfer and thermodynamic power cycles Bridging the gap between the fundamental concepts of fluid mechanics, heat transfer and thermodynamics, and the practical design of thermo-fluids components and systems, this textbook focuses on the design of internal fluid flow systems, coiled heat exchangers and performance analysis of power plant systems. The topics are arranged so that each builds upon the previous chapter to convey to the reader that topics are not stand-alone i

40 CFR 60.105a - Monitoring of emissions and operations for fluid catalytic cracking units (FCCU) and fluid coking...

Science.gov (United States)

2010-07-01

..., Catalytic Reforming Units, and Sulfur Recovery Units. (iii) The owner or operator shall install, operate... for fluid catalytic cracking units (FCCU) and fluid coking units (FCU). 60.105a Section 60.105a... and operations for fluid catalytic cracking units (FCCU) and fluid coking units (FCU). (a) FCCU and...

Endoscopic management of peripancreatic fluid collections.

Science.gov (United States)

Goyal, Jatinder; Ramesh, Jayapal

2015-07-01

Peripancreatic fluid collections are a well-known complication of pancreatitis and can vary from fluid-filled collections to entirely necrotic collections. Although most of the fluid-filled pseudocysts tend to resolve spontaneously with conservative management, intervention is necessary in symptomatic patients. Open surgery has been the traditional treatment modality of choice though endoscopic, laparoscopic and transcutaneous techniques offer alternative drainage approaches. During the last decade, improvement in endoscopic ultrasound technology has enabled real-time access and drainage of fluid collections that were previously not amenable to blind transmural drainage. This has initiated a trend towards use of this modality for treatment of pseudocysts. In this review, we have summarised the existing evidence for endoscopic drainage of peripancreatic fluid collections from published studies.

Fluid Structure Interaction for Hydraulic Problems

International Nuclear Information System (INIS)

Souli, Mhamed; Aquelet, Nicolas

2011-01-01

Fluid Structure interaction plays an important role in engineering applications. Physical phenomena such as flow induced vibration in nuclear industry, fuel sloshing tank in automotive industry or rotor stator interaction in turbo machinery, can lead to structure deformation and sometimes to failure. In order to solve fluid structure interaction problems, the majority of numerical tests consists in using two different codes to separately solve pressure of the fluid and structural displacements. In this paper, a unique code with an ALE formulation approach is used to implicitly calculate the pressure of an incompressible fluid applied to the structure. The development of the ALE method as well as the coupling in a computational structural dynamic code, allows to solve more large industrial problems related to fluid structure coupling. (authors)

Supercritical fluid chromatography

Science.gov (United States)

Vigdergauz, M. S.; Lobachev, A. L.; Lobacheva, I. V.; Platonov, I. A.

1992-03-01

The characteristic features of supercritical fluid chromatography (SCFC) are examined and there is a brief historical note concerning the development of the method. Information concerning the use of supercritical fluid chromatography in the analysis of objects of different nature is presented in the form of a table. The roles of the mobile and stationary phases in the separation process and the characteristic features of the apparatus and of the use of the method in physicochemical research are discussed. The bibliography includes 364 references.

Compressible Fluid Suspension Performance Testing

National Research Council Canada - National Science Library

Hoogterp, Francis

2003-01-01

... compressible fluid suspension system that was designed and installed on the vehicle by DTI. The purpose of the tests was to evaluate the possible performance benefits of the compressible fluid suspension system...

Understanding, Classifying, and Selecting Environmentally Acceptable Hydraulic Fluids

Science.gov (United States)

2016-08-01

traditional mineral oil; therefore, the life cycle costs over time may be reduced . REPLACEMENT OF EXISTING HYDRAULIC FLUIDS: Hydraulic fluids in existing...properly maintaining the fluid can extend the time interval between fluid changes, thus reducing the overall operating cost of the EA hydraulic fluid. It...Environmentally Acceptable Hydraulic Fluids by Timothy J. Keyser, Robert N. Samuel, and Timothy L. Welp INTRODUCTION: On a daily basis, the United States Army

Markov-modulated and feedback fluid queues

NARCIS (Netherlands)

Scheinhardt, Willem R.W.

1998-01-01

In the last twenty years the field of Markov-modulated fluid queues has received considerable attention. In these models a fluid reservoir receives and/or releases fluid at rates which depend on the actual state of a background Markov chain. In the first chapter of this thesis we give a short

21 CFR 886.4275 - Intraocular fluid.

Science.gov (United States)

2010-04-01

... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4275 Intraocular fluid. (a) Identification. An intraocular fluid is a device consisting of a nongaseous fluid intended to be introduced into the eye to aid... section 515 of the act is required before this device may be commercially distributed. See § 886.3. ...

Fluid element in SAP IV

International Nuclear Information System (INIS)

Yilmaz, C.; Akkas, N.

1979-01-01

In previous studies a fluid element is incorporated in the widely used general purpose finite element program SAPIV. This type of problem is of interest in the design of nuclear components involving geometric complexities and nonlinearities. The elasticity matrix of a general-purpose finite element program is modified in such a way that it becomes possible to idealize fluid as a structural finite element with zero shear modulus and a given bulk modules. Using the modified version of SAPIV, several solid-fluid interactions problems are solved. The numerical solutions are compared with the available analytical solutions. They are shown to be in reasonable aggrement. It is also shown that by solving an exterior-fluid interaction problem, the pressure wave propagation in the acoustic medium can be solved with the same approach. In this study, two of the problem not studied in the previous work will be presented. These problems are namely the effects of the link elements used at solid-fluid interfaces and of the concentrated loads on the response of the fluid medium. Truss elements are used as the link elements. After these investigations, it is decided that general purpose finite element programs with slight modifications can be used in the safety analysis of nuclear reactor plants. By this procedure it is possible to handle two-dimensional plane strain and tridimensional axisymmetric problems of this type. (orig.)

Extended two-fluid model for simulating magneto-rheological fluid flows

International Nuclear Information System (INIS)

Shivaram, A C

2011-01-01

The current practice of designing magneto-rheological (MR) fluid-based devices is, to a large extent, based on simple phenomenological models like the Bingham model. Though useful for initial force or torque estimation and sizing, these models lack the capability to predict performance degradation due to changes in the particle volume fraction distribution. The present work demonstrates the use of the two-fluid model for predicting the particle volume fraction distribution inside a device in the absence of a field and proposes a novel modeling scheme which can simulate the fluid flow in the presence of a field. This modeling scheme can be used to (a) visualize flow patterns inside a device under various operating conditions, (b) predict the spatial distribution of particles inside a device after multiple operating cycles, (c) assist in estimating the extent of performance degradation due to non-uniform particle distribution and (d) enable testing of various design strategies to mitigate such performance issues using simulations. This is illustrated through numerical examples of a few case studies of typical MR device configurations

Fluid-structure-coupling algorithm

International Nuclear Information System (INIS)

McMaster, W.H.; Gong, E.Y.; Landram, C.S.; Quinones, D.F.

1980-01-01

A fluid-structure-interaction algorithm has been developed and incorporated into the two dimensional code PELE-IC. This code combines an Eulerian incompressible fluid algorithm with a Lagrangian finite element shell algorithm and incorporates the treatment of complex free surfaces. The fluid structure, and coupling algorithms have been verified by the calculation of solved problems from the literature and from air and steam blowdown experiments. The code has been used to calculate loads and structural response from air blowdown and the oscillatory condensation of steam bubbles in water suppression pools typical of boiling water reactors. The techniques developed here have been extended to three dimensions and implemented in the computer code PELE-3D

Fluid structure coupling algorithm

International Nuclear Information System (INIS)

McMaster, W.H.; Gong, E.Y.; Landram, C.S.; Quinones, D.F.

1980-01-01

A fluid-structure-interaction algorithm has been developed and incorporated into the two-dimensional code PELE-IC. This code combines an Eulerian incompressible fluid algorithm with a Lagrangian finite element shell algorithm and incorporates the treatment of complex free surfaces. The fluid structure and coupling algorithms have been verified by the calculation of solved problems from the literature and from air and steam blowdown experiments. The code has been used to calculate loads and structural response from air blowdown and the oscillatory condensation of steam bubbles in water suppression pools typical of boiling water reactors. The techniques developed have been extended to three dimensions and implemented in the computer code PELE-3D

Geophysical fluid dynamics

CERN Document Server

Pedlosky, Joseph

1982-01-01

The content of this book is based, largely, on the core curriculum in geophys­ ical fluid dynamics which land my colleagues in the Department of Geophysical Sciences at The University of Chicago have taught for the past decade. Our purpose in developing a core curriculum was to provide to advanced undergraduates and entering graduate students a coherent and systematic introduction to the theory of geophysical fluid dynamics. The curriculum and the outline of this book were devised to form a sequence of courses of roughly one and a half academic years (five academic quarters) in length. The goal of the sequence is to help the student rapidly advance to the point where independent study and research are practical expectations. It quickly became apparent that several topics (e. g. , some aspects of potential theory) usually thought of as forming the foundations of a fluid-dynamics curriculum were merely classical rather than essential and could be, however sadly, dispensed with for our purposes. At the same tim...

Geophysical fluid dynamics

CERN Document Server

Pedlosky, Joseph

1979-01-01

The content of this book is based, largely, on the core curriculum in geophys­ ical fluid dynamics which I and my colleagues in the Department of Geophysical Sciences at The University of Chicago have taught for the past decade. Our purpose in developing a core curriculum was to provide to advanced undergraduates and entering graduate students a coherent and systematic introduction to the theory of geophysical fluid dynamics. The curriculum and the outline of this book were devised to form a sequence of courses of roughly one and a half academic years (five academic quarters) in length. The goal of the sequence is to help the student rapidly advance to the point where independent study and research are practical expectations. It quickly became apparent that several topics (e. g. , some aspects of potential theory) usually thought of as forming the foundations of a fluid-dynamics curriculum were merely classical rather than essential and could be, however sadly, dispensed with for our purposes. At the same ti...

Fundamental trends in fluid-structure interaction

CERN Document Server

Galdi, Giovanni P

2010-01-01

The interaction of a fluid with a solid body is a widespread phenomenon in nature, occurring at different scales and different applied disciplines. Interestingly enough, even though the mathematical theory of the motion of bodies in a liquid is one of the oldest and most classical problems in fluid mechanics, mathematicians have, only very recently, become interested in a systematic study of the basic problems related to fluid-structure interaction, from both analytical and numerical viewpoints. ""Fundamental Trends in Fluid-Structure Interaction"" is a unique collection of important papers wr

Reduced viscosity interpreted for fluid/gas mixtures

Science.gov (United States)

Lewis, D. H.

1981-01-01

Analysis predicts decrease in fluid viscosity by comparing pressure profile of fluid/gas mixture with that of power-law fluid. Fluid is taken to be viscous, non-Newtonian, and incompressible; the gas to be ideal; the flow to be inertia-free, isothermal, and one dimensional. Analysis assists in design of flow systems for petroleum, coal, polymers, and other materials.

Spinning fluids in general relativity

Science.gov (United States)

Ray, J. R.; Smalley, L. L.

1982-01-01

General relativity field equations are employed to examine a continuous medium with internal spin. A variational principle formerly applied in the special relativity case is extended to the general relativity case, using a tetrad to express the spin density and the four-velocity of the fluid. An energy-momentum tensor is subsequently defined for a spinning fluid. The equations of motion of the fluid are suggested to be useful in analytical studies of galaxies, for anisotropic Bianchi universes, and for turbulent eddies.

Intra-slab COH fluid fluxes evidenced by fluid-mediated decarbonation of lawsonite eclogite-facies altered oceanic metabasalts

Science.gov (United States)

Vitale Brovarone, Alberto; Chu, Xu; Martin, Laure; Ague, Jay J.; Monié, Patrick; Groppo, Chiara; Martinez, Isabelle; Chaduteau, Carine

2018-04-01

The interplay between the processes controlling the mobility of H2O and C-bearing species during subduction zone metamorphism exerts a critical control on plate tectonics and global volatile recycling. Here we present the first study on fresh, carbonate-bearing, lawsonite eclogite-facies metabasalts from Alpine Corsica, France, which reached the critical depths at which important devolatilization reactions occur in subducting slabs. The studied samples indicate that the evolution of oceanic crustal sequences subducted under present-day thermal regimes is dominated by localized fluid-rock interactions that are strongly controlled by the nature and extent of inherited (sub)seafloor hydrothermal processes, and by the possibility of deep fluids to be channelized along inherited or newly-formed discontinuities. Fluid channelization along inherited discontinuities controlled local rehydration and dehydration/decarbonation reactions and the stability of carbonate and silicate minerals at the blueschist-eclogite transition. Fluid-mediated decarbonation was driven by upward, up-temperature fluid flow in the inverted geothermal gradient of a subducting oceanic slab, a process that has not been documented in natural samples to date. We estimate that the observed fluid-rock reactions released 20-60 kg CO2 per m3 of rock (i.e. 0.7-2.1 wt% CO2), which is in line with the values predicted from decarbonation of metabasalts in open systems at these depths. Conversely, the estimated time-integrated fluid fluxes (20-50 t/m2) indicate that the amount of carbon transported by channelized fluid flow within the volcanic part of subducting oceanic plates is potentially much higher than previous numerical estimates, testifying to the percolation of C-bearing fluids resulting from devolatilization/dissolution processes operative in large reservoirs.

Engineering Fracking Fluids with Computer Simulation

Science.gov (United States)

Shaqfeh, Eric

2015-11-01

There are no comprehensive simulation-based tools for engineering the flows of viscoelastic fluid-particle suspensions in fully three-dimensional geometries. On the other hand, the need for such a tool in engineering applications is immense. Suspensions of rigid particles in viscoelastic fluids play key roles in many energy applications. For example, in oil drilling the ``drilling mud'' is a very viscous, viscoelastic fluid designed to shear-thin during drilling, but thicken at stoppage so that the ``cuttings'' can remain suspended. In a related application known as hydraulic fracturing suspensions of solids called ``proppant'' are used to prop open the fracture by pumping them into the well. It is well-known that particle flow and settling in a viscoelastic fluid can be quite different from that which is observed in Newtonian fluids. First, it is now well known that the ``fluid particle split'' at bifurcation cracks is controlled by fluid rheology in a manner that is not understood. Second, in Newtonian fluids, the presence of an imposed shear flow in the direction perpendicular to gravity (which we term a cross or orthogonal shear flow) has no effect on the settling of a spherical particle in Stokes flow (i.e. at vanishingly small Reynolds number). By contrast, in a non-Newtonian liquid, the complex rheological properties induce a nonlinear coupling between the sedimentation and shear flow. Recent experimental data have shown both the shear thinning and the elasticity of the suspending polymeric solutions significantly affects the fluid-particle split at bifurcations, as well as the settling rate of the solids. In the present work, we use the Immersed Boundary Method to develop computer simulations of viscoelastic flow in suspensions of spheres to study these problems. These simulations allow us to understand the detailed physical mechanisms for the remarkable physical behavior seen in practice, and actually suggest design rules for creating new fluid recipes.

Levels of lipocalin-2 in crevicular fluid and tear fluid in chronic periodontitis and obesity subjects.

Science.gov (United States)

Pradeep, Avani Raju; Nagpal, Kanika; Karvekar, Shruti; Patnaik, Kaushik

2016-11-01

Lipocalin-2, a 25 kDa secretory glycoprotein, was first found in the neutrophilic granules of humans and in mouse kidney cells. It has been shown to have an important role in inflammation. The aim of this study was to determine the levels of lipocalin-2 in gingival crevicular fluid and tear fluid in patients with obesity and chronic periodontitis. A total of 40 subjects in the age group 25-40 years were divided into four groups based on probing depth, gingival index, clinical attachment level, body mass index, and radiographic evidence of bone loss. The groups were: nonobese healthy group; obese healthy group; nonobese chronic periodontitis group; obese chronic periodontitis group Gingival crevicular fluid and tear fluid samples were collected on the subsequent day. There was an increase in lipocalin-2 levels from group 1 to group 4 (with the nonobese healthy group showing the least levels and obese chronic periodontitis group showing the highest levels) in both gingival crevicular fluid and tear fluid. Lipocalin-2 may be an important inflammatory marker that may help link obesity and chronic periodontitis. © 2015 Wiley Publishing Asia Pty Ltd.

Biochemical Analysis of Synovial Fluid, Cerebrospinal Fluid and Vitreous Humor at Early Postmortem Intervals in Donkeys

Directory of Open Access Journals (Sweden)

Doha Yahia

2014-01-01

Full Text Available Biochemical analysis of body fluids after death is a helpful tool in veterinary forensic medicine. Synovial fluid, cerebrospinal fluid (CSF and vitreous humor are easily accessible and well preserved from contamination. Five donkeys (Equus africanus asinus aged 1 - 2 years old were subjected to the study. Samples (Synovial fluid, CSF and vitreous humor were collected before death (antimortem and then at 2, 4, 6, 8, 10 and 12 hours postmortem. Samples were analyzed for glucose, chloride, sodium, magnesium, potassium, enzymes and total protein. Synovial fluid analysis showed that glucose concentration started to decrease at 6 hours postmortem, while magnesium level increased with time. Other parameters were more stable. CSF analysis showed several changes related to time after death as the decrease in glucose and sodium levels, and the increased levels of potassium, magnesium, calcium and total protein. Vitreous analysis revealed a reduction in glucose level and increased potassium and magnesium concentrations. The present study concluded that biochemical analysis of synovial fluid, vitreous humor and CSF can help in determination of time since death in donkeys. This study recommend using CSF for determination of early post-mortem intervals.

A numerical method for interaction problems between fluid and membranes with arbitrary permeability for fluid

Science.gov (United States)

Miyauchi, Suguru; Takeuchi, Shintaro; Kajishima, Takeo

2017-09-01

We develop a numerical method for fluid-membrane interaction accounting for permeation of the fluid using a non-conforming mesh to the membrane shape. To represent the permeation flux correctly, the proposed finite element discretization incorporates the discontinuities in the velocity gradient and pressure on the membrane surface with specially selected base functions. The discontinuities are represented with independent variables and determined to satisfy the governing equations including the interfacial condition on the permeation. The motions of the fluid, membrane and permeation flux are coupled monolithically and time-advanced fully-implicitly. The validity and effectiveness of the proposed method are demonstrated by several two-dimensional fluid-membrane interaction problems of Stokes flows by comparing with the analytical models and numerical results obtained by other methods. The reproduced sharp discontinuities are found to be essential to suppress the non-physical permeation flux. Further, combined with the numerical treatment for the solute concentration across the membrane, the proposed method is applied to a fluid-structure interaction problem including the osmotic pressure difference.

Unsteady magnetohydrodynamics micropolar fluid in boundary layer flow past a sphere influenced by magnetic fluid

Science.gov (United States)

Pratomo, Rizky Verdyanto; Widodo, Basuki; Adzkiya, Dieky

2017-12-01

Research about fluid flow was very interesting because have a lot of advantages and it can be applied in many aspects of life. The study on fluid flow which is now widely studied is on magnetohydrodynamic (MHD). Magnetohydrodynamic is a conductive and electrical in a magnetic field. This paper considers the effect of unsteady magnetic fields on the flow of magneto-hydrodynamic fluid on the boundary layer that flows past a sphere in micropolar fluid influenced by magnetic field. Our approach is as follows. First, we construct a mathematical model and then the system of equations obtained will be solved numerically using the Keller-Box scheme. Then the system is simulated to assess its effect on the fluid flow velocity profile and the profile of microrotation particles. The result of this research indicates, that when the magnetic parameters increase, then velocity profile increases. If material parameters increase, then velocity profile decreases and magnetic parameters increase for n = 0. For n = 0.5, if magnetic parameters increase, then microrotation profile decreases.

Electrokinetic effects and fluid permeability

International Nuclear Information System (INIS)

Berryman, J.G.

2003-01-01

Fluid permeability of porous media depends mainly on connectivity of the pore space and two physical parameters: porosity and a pertinent length-scale parameter. Electrical imaging methods typically establish connectivity and directly measure electrical conductivity, which can then often be related to porosity by Archie's law. When electrical phase measurements are made in addition to the amplitude measurements, information about the pertinent length scale can then be obtained. Since fluid permeability controls the ability to flush unwanted fluid contaminants from the subsurface, inexpensive maps of permeability could improve planning strategies for remediation efforts. Detailed knowledge of fluid permeability is also important for oil field exploitation, where knowledge of permeability distribution in three dimensions is a common requirement for petroleum reservoir simulation and analysis, as well as for estimates on the economics of recovery

Single-particle Schroedinger fluid. I. Formulation

International Nuclear Information System (INIS)

Kan, K.K.; Griffin, J.J.

1976-01-01

The problem of a single quantal particle moving in a time-dependent external potential well is formulated specifically to emphasize and develop the fluid dynamical aspects of the matter flow. This idealized problem, the single-particle Schroedinger fluid, is shown to exhibit already a remarkably rich variety of fluid dynamical features, including compressible flow and line vortices. It provides also a sufficient framework to encompass simultaneously various simplified fluidic models for nuclei which have earlier been postulated on an ad hoc basis, and to illuminate their underlying restrictions. Explicit solutions of the single-particle Schroedinger fluid problem are studied in the adiabatic limit for their mathematical and physical implications (especially regarding the collective kinetic energy). The basic generalizations for extension of the treatment to the many-body Schroedinger fluid are set forth

Evaluation of the truncated perturbed chain-polar statistical associating fluid theory for complex mixture fluid phase equilibria

DEFF Research Database (Denmark)

Karakatsani, Eirini; Kontogeorgis, Georgios; Economou, Ioannis

2006-01-01

Perturbed chain-statistical associating fluid theory (PC-SAFT) was extended rigorously to polar fluids based on the theory of Stell and co-workers [Mol. Phys. 1977, 33, 987]. The new PC-PSAFT was simplified to truncated PC-PSAFT (tPC-PSAFT) so that it can be practical for real polar fluid...

Working Fluid Stability in Large-Scale Organic Rankine Cycle-Units Using Siloxanes—Long-Term Experiences and Fluid Recycling

Directory of Open Access Journals (Sweden)

Tobias G. Erhart

2016-05-01

Full Text Available The results in this work show the influence of long-term operation on the decomposition of working fluids in eight different organic rankine cycle (ORC power plants (both heat-led and electricity-led in a range of 900 kW el to 2 MW el . All case study plants are using octamethyltrisiloxane (MDM as a working fluid; the facilities are between six to 12 years old. Detailed analyses, including the fluid distribution throughout the cycle, are conducted on one system. All presented fluid samples are analyzed via head space gas chromatography mass spectrometry (HS-GC-MS. Besides the siloxane composition, the influence of contaminants, such as mineral oil-based lubricants (and their components, is examined. In most cases, the original working fluid degrades to fractions of siloxanes with a lower boiling point (low boilers and fractions with a higher boiling point (high boilers. As a consequence of the analyses, a new fluid recycling and management system was designed and tested in one case study plant (Case Study #8. Pre-post comparisons of fluid samples prove the effectiveness of the applied methods. The results show that the recovery of used working fluid offers an alternative to the purchase of fresh fluid, since operating costs can be significantly reduced. For large facilities, the prices for new fluid range from € 15 per liter (in 2006 to € 22 per liter (in 2013, which is a large reinvestment, especially in light of filling volumes of 4000 liters to 7000 liters per unit. Using the aforementioned method, a price of € 8 per liter of recovered MDM can be achieved.

Simulation of the deformation of a fluid domain in motion in another fluid by the boundary element method

International Nuclear Information System (INIS)

Rocchi-Tavares, Miriam

1992-01-01

The objective of this research thesis is to model the sustentation (or aerodynamic levitation) of a drop by a fluid flowing through a porous plate. More precisely, the author developed a general calculation tool to solve the Stokes problem by using the boundary element method. The author reports the calculation of stresses at the surface of a solid body moving in an infinite medium, in order to validate the calculation tool before its extension to more complex problems. Then, the model is developed to describe the deformation of a fluid mass moving in another fluid. The surrounding environment is either infinite or limited by a plane wall which can be impervious or crossed by an ambient fluid. Then, the author addresses the study of the evolution of the surface of a drop moving in an infinite medium, analyses the behaviour of a fluid mass at the vicinity of a plane, infinite and impervious wall. The last part addresses the sustentation of a deformable fluid body above a porous plane wall crossed by another fluid [fr

Local linear viscoelasticity of confined fluids.

Science.gov (United States)

Hansen, J S; Daivis, P J; Todd, B D

2007-04-14

In this paper the authors propose a novel method to study the local linear viscoelasticity of fluids confined between two walls. The method is based on the linear constitutive equation and provides details about the real and imaginary parts of the local complex viscosity. They apply the method to a simple atomic fluid undergoing zero mean oscillatory flow using nonequilibrium molecular dynamics simulations. The method shows that the viscoelastic properties of the fluid exhibit dramatic spatial changes near the wall-fluid boundary due to the high density in this region. It is also shown that the real part of the viscosity converges to the frequency dependent local shear viscosity sufficiently far away from the wall. This also provides valuable information about the transport properties in the fluid, in general. The viscosity is compared with predictions from the local average density model. The two methods disagree in that the local average density model predicts larger viscosity variations near the wall-fluid boundary than what is observed through the method presented here.

Critical asymmetry in renormalization group theory for fluids.

Science.gov (United States)

Zhao, Wei; Wu, Liang; Wang, Long; Li, Liyan; Cai, Jun

2013-06-21

The renormalization-group (RG) approaches for fluids are employed to investigate critical asymmetry of vapour-liquid equilibrium (VLE) of fluids. Three different approaches based on RG theory for fluids are reviewed and compared. RG approaches are applied to various fluid systems: hard-core square-well fluids of variable ranges, hard-core Yukawa fluids, and square-well dimer fluids and modelling VLE of n-alkane molecules. Phase diagrams of simple model fluids and alkanes described by RG approaches are analyzed to assess the capability of describing the VLE critical asymmetry which is suggested in complete scaling theory. Results of thermodynamic properties obtained by RG theory for fluids agree with the simulation and experimental data. Coexistence diameters, which are smaller than the critical densities, are found in the RG descriptions of critical asymmetries of several fluids. Our calculation and analysis show that the approach coupling local free energy with White's RG iteration which aims to incorporate density fluctuations into free energy is not adequate for VLE critical asymmetry due to the inadequate order parameter and the local free energy functional used in the partition function.

Hydrothermal Fluid evolution in the Dalli porphyry Cu-Au Deposit: Fluid Inclusion microthermometry studies

Directory of Open Access Journals (Sweden)

Alireza Zarasvandi

2015-10-01

Full Text Available Introduction A wide variety of world-class porphyry Cu deposits occur in the Urumieh-Dohktar magmatic arc (UDMA of Iran.The arc is composed of calc-alkaline granitoid rocks, and the ore-hosting porphyry intrusions are dominantly granodiorite to quartz-monzonite (Zarasvandi et al., 2015. It is believed that faults played an important role in the emplacement of intrusions and subsequentporphyry-copper type mineralization (Shahabpour, 1999. Three main centers host the porphyry copper mineralization in the UDMA: (1 Ardestan-SarCheshmeh-Kharestan zone, (2 Saveh-Ardestan district; in the central parts of the UDMA, hosting the Dalli porphyry Cu-Au deposit, and (3 Takab-Mianeh-Qharahdagh-Sabalan zone. Mineralized porphyry coppersystems in the UDMA are restricted to Oligocene to Mioceneintrusions and show potassic, sericitic, argillic, propylitic and locally skarn alteration (Zarasvandi et al., 2005; Zarasvandi et al., 2015. In the Dalli porphyry deposit, four hydrothermal alteration zones, includingpotassic, sericitic, propylitic, and argillic types have been described in the two discrete mineralized areas, namely, northern and southern stocks. Hypogenemineralization includes chalcopyrite, pyrite, and magnetite, with minor occurrences of bornite.Supergene activity has produced gossan, oxidized minerals and enrichment zones. The supergene enrichment zone contains chalcocite and covellite with a 10-20 m thickness. Mineralization in the northern stock is mainly composed of pyrite and chalcopyrite. The aim of this study is the investigation and classification of hydrothermal veins and the constraining of physicochemical compositions of ore-forming fluids using systematic investigation of fluid inclusions. Materials and methods Twenty samples were collected from drill holes. Thin and polished sections were prepared from hydrothermal veins of thepotassic, sericitic and propylitic alteration zones. Samples used for fluid inclusion measurements were collected

Advances in Environmental Fluid Mechanics

CERN Document Server

Mihailovic, Dragutin T

2010-01-01

Environmental fluid mechanics (EFM) is the scientific study of transport, dispersion and transformation processes in natural fluid flows on our planet Earth, from the microscale to the planetary scale. This book brings together scientists and engineers working in research institutions, universities and academia, who engage in the study of theoretical, modeling, measuring and software aspects in environmental fluid mechanics. It provides a forum for the participants, and exchanges new ideas and expertise through the presentations of up-to-date and recent overall achievements in this field.

Fluid Sampling under Adverse Conditions Echantillonnage des fluides en conditions difficiles

Directory of Open Access Journals (Sweden)

Williams J. M.

2006-12-01

Full Text Available Valid samples are essential to the proper description of reservoir fluids; if the samples are not representative, all measurements on them will be invalid. This paper discusses the principal challenges facing fluid sampling including gas condensate reservoirs, compositional gradients, water content of hydrocarbon fluids, asphaltene deposition, wax formation, oil base mud contamination, and reactive components. It also reports the major technological advances recently made in this field. It reviews developments in sampling techniques such as MDT-type tools, new DST sampling tools, coiled tubing sampling, and isokinetic techniques, and it highlights common limitations. The value of making proper use of existing technology is emphasized, both with traditional techniques and new developments, with reference to correct well conditioning, interpretation of field data, and especially to optimum handling of samples. The paper emphasizes the need for better exchange of sampling knowledge between organizations, and highlights the lack of up-to-date industry standards with respect to fluid sampling. A solution is proposed in the form of a joint industry project to identify and document best practices. Des échantillons valables sont essentiels pour bien caractériser les fluides de gisements. Si les échantillons ne sont pas représentatifs, toutes les mesures ultérieures seront entachées d'erreurs. Cet article discute les principaux défis en matière d'échantillonnage, en particulier les réservoirs de gaz à condensats, les gradients compositionnels, la teneur en eau des fluides hydrocarbonés, les dépôts d'asphaltènes, les dépôts de paraffines, la contamination par les boues à base d'huile, et les constituants réactifs. Il relate également les principaux progrès technologiques récemment réalisés dans ce domaine et passe en revue les développements des techniques d'échantillonnage telles que les outils de type MDT, les nouveaux outils d

Deciphering fluid inclusions in high-grade rocks

Directory of Open Access Journals (Sweden)

Alfons van den Kerkhof

2014-09-01

Full Text Available The study of fluid inclusions in high-grade rocks is especially challenging as the host minerals have been normally subjected to deformation, recrystallization and fluid-rock interaction so that primary inclusions, formed at the peak of metamorphism are rare. The larger part of the fluid inclusions found in metamorphic minerals is typically modified during uplift. These late processes may strongly disguise the characteristics of the “original” peak metamorphic fluid. A detailed microstructural analysis of the host minerals, notably quartz, is therefore indispensable for a proper interpretation of fluid inclusions. Cathodoluminescence (CL techniques combined with trace element analysis of quartz (EPMA, LA-ICPMS have shown to be very helpful in deciphering the rock-fluid evolution. Whereas high-grade metamorphic quartz may have relatively high contents of trace elements like Ti and Al, low-temperature re-equilibrated quartz typically shows reduced trace element concentrations. The resulting microstructures in CL can be basically distinguished in diffusion patterns (along microfractures and grain boundaries, and secondary quartz formed by dissolution-reprecipitation. Most of these textures are formed during retrograde fluid-controlled processes between ca. 220 and 500 °C, i.e. the range of semi-brittle deformation (greenschist-facies and can be correlated with the fluid inclusions. In this way modified and re-trapped fluids can be identified, even when there are no optical features observed under the microscope.

Effects of drilling fluids on marine organisms

International Nuclear Information System (INIS)

Parrish, P.R.; Duke, T.W.

1990-01-01

This paper reports on drilling fluids, also called drilling muds, which are essential to drilling processes in the exploration and production of oil and gas from the U.S. Outer Continental Shelf (OCS). These fluids are usually discharged from drilling platforms into surrounding waters of the OCS and are regulated by the U.S. Environmental Protection Agency (EPA). In a program carried out by the EPA Environmental research Laboratory at Gulf Breeze, Florida, diverse marine species as well as microbiotic and macrobiotic communities were studied. Drilling fluids were toxic to marine organisms in certain concentrations and exposure regimes. Furthermore, the fluids adversely affected the benthos physically by burying them or by altering the substrates. Toxicity of the drilling-fluid components, used drilling fluids from active Gulf of Mexico sites, and laboratory-prepared drilling fluids varied considerably. for example 96-h LC 50 s were from 25 μ liter -1 to > 1500 μl liter -1 for clams, larval lobsters, mysids, and grass shrimp. In most instances, mortality was significantly (α = 0.05) correlated with the diesel-oil content of the fluids collected from the Gulf of Mexico. Data and model simulations suggest a rapid dilution of drilling fluids released into OCS waters, resulting in concentrations below the acute-effect concentration for the water column organisms tested

Physics of field-responsive fluids

Science.gov (United States)

Wan, Tsz Kai Jones

Electrorheological (ER) fluid is a new class of material, which possesses a variety of potential applications, such as shock absorbers and clutches. It is formed by microparticles that are dispersed in a host fluid. The particles will form chains rapidly when we apply an electric field to the ER fluid. However, due to the inadequacy of knowledge, the proposed applications have not been commercialized yet. The prediction of the strength of the ER effect is the main concern in the theoretical investigation of ER fluids. The ER effect is originated from the induced interaction between the polarized particles in an ER fluid. Existing theories assume that the particles are at rest. In a realistic situation, the fluid flow exerts force and torque on the particles, setting the particles in both translational and rotational motions under these actions. Recent experiments showed that the induced forces between the rotating particles are markedly different from the values predicted by existing theories. To overcome the discrepancy between theory and experiment, we formulate a model to take the particle motion into account, and derive the dependence of forces on the angular velocity of the rotating particles. We develop first-principles methods to investigate the dynamic ER effects in which the suspended particles can have translational or rotational motions. A model based on the relaxation of polarization charge on the particle surfaces is proposed and solved for various experimental conditions. The method can be extended to study the ER effects of coated particles, crystalline particles, and to the magnetorheological effects of paramagnetic particles. Moreover, the nonlinear ER effects under a strong applied field will be studied by the same approach. The results may help in the preparation of materials for the design of ER fluids.

Turbine lubrication fluid varnish mitigation

Energy Technology Data Exchange (ETDEWEB)

Farooq, Khalid [Pall Corporation, Port Washington, NY (United States)

2010-04-15

Varnish deposits on internal surfaces in turbine lube systems result in a number of adverse operational issues, especially the restriction and sticking of the moving parts of servo- or directional control valves, resulting in their malfunction. The lubrication fluid has limited solvency for the varnish-forming material, hence a typical turbine will have the majority of this material as deposits and a relatively small portion as suspension in the fluid phase, in quasi-equilibrium with the deposits. The lube system needs to be cleaned by removing the suspended varnish-forming material from the fluid phase, which allows the deposits to re-entrain into the fluid phase, until the majority of the transferable deposits are removed and the fluid carries no significant amount of the material to have any adverse effect. The methods used for the removal of varnish from turbine lube systems include chemical cleaning/flushing, electrostatic charge induced agglomeration/retention, and the adsorption of the varnish suspended in the oil on an adsorbent medium. The paper discusses an absorption-based removal method that utilizes a fibrous medium that has pronounced affinity for the removal and retention of the varnish-forming material from the fluid as well as the deposits from surfaces that are in quasi-equilibrium with the varnish precursors in the fluid. The filtration medium is a composite, made with cellulose bonded by specially formulated, temperature-cured resins. The absorptive medium exhibits high structural and chemical integrity and has been thoroughly tested on operating turbines, showing reduction in varnish levels from the critical range to below normal range in a relatively short time. The experience with the utilization of the absorptive medium in laboratory tests and in two operating turbines is presented. (orig.)

FORMATE-BASED FLUIDS: FORMULATION AND APPLICATION

Directory of Open Access Journals (Sweden)

Nediljka Gaurina-Međimurec

2008-12-01

Full Text Available Formate-based fluids has been successfully used in over hunders HPHT well operations since they introduced in field practice. They have many advantages when compared with conventional HPHT drilling and completion fluids such as: minimal formation damage, maintenance of additve properties at high temperatures, reduced hydraulic flow resistance, low potential for differential sticking, naturally lubricating, very low corrosion rates, biodegradable and pose little risk to the environment etc. Formate-based fluids can be applied during deep slim hole drilling, shale drilling, reservoir drilling, salt and gas hydrate formations drilling. The laboratory research was carried out to evaluate the rheological behavior of formate-based fluids as a function of temperature. Formate-based fluids were formulated using potassium formate brine, xanthan polymer, PAC, starch and calcium carbonate. Experimental results show that potassium formate improves the thermal stability of polymers.

Bifurcated SEN with Fluid Flow Conditioners

Directory of Open Access Journals (Sweden)

F. Rivera-Perez

2014-01-01

Full Text Available This work evaluates the performance of a novel design for a bifurcated submerged entry nozzle (SEN used for the continuous casting of steel slabs. The proposed design incorporates fluid flow conditioners attached on SEN external wall. The fluid flow conditioners impose a pseudosymmetric pattern in the upper zone of the mold by inhibiting the fluid exchange between the zones created by conditioners. The performance of the SEN with fluid flow conditioners is analyzed through numerical simulations using the CFD technique. Numerical results were validated by means of physical simulations conducted on a scaled cold water model. Numerical and physical simulations confirmed that the performance of the proposed SEN is superior to a traditional one. Fluid flow conditioners reduce the liquid free surface fluctuations and minimize the occurrence of vortexes at the free surface.

Symmetry breaking in fluid dynamics: Lie group reducible motions for real fluids

International Nuclear Information System (INIS)

Holm, D.D.

1976-07-01

The physics of fluids is based on certain kinematical invariance principles, which refer to coordinate systems, dimensions, and Galilean reference frames. Other, thermodynamic, symmetry principles are introduced by the material description. In the present work, the interplay between these two kinds of invariance principles is used to solve for classes of one-dimensional non-steady isentropic motions of a fluid whose equation of state is of Mie-Gruneisen type. Also, the change in profile and attenuation of weak shock waves in a dissipative medium is studied at the level of Burgers' approximation from the viewpoint of its underlying symmetry structure. The mathematical method of approach is based on the theory of infinitesimal Lie groups. Fluid motions are characterized according to inequivalent subgroups of the full invariance group of the flow description and exact group reducible solutions are presented

Thin-Film Magnetic-Field-Response Fluid-Level Sensor for Non-Viscous Fluids

Science.gov (United States)

Woodard, Stanley E.; Shams, Qamar A.; Fox, Robert L.; Taylor, Bryant D.

2008-01-01

An innovative method has been developed for acquiring fluid-level measurements. This method eliminates the need for the fluid-level sensor to have a physical connection to a power source or to data acquisition equipment. The complete system consists of a lightweight, thin-film magnetic-field-response fluid-level sensor (see Figure 1) and a magnetic field response recorder that was described in Magnetic-Field-Response Measurement-Acquisition System (LAR-16908-1), NASA Tech Briefs, Vol. 30, No. 6 (June 2006), page 28. The sensor circuit is a capacitor connected to an inductor. The response recorder powers the sensor using a series of oscillating magnetic fields. Once electrically active, the sensor responds with its own harmonic magnetic field. The sensor will oscillate at its resonant electrical frequency, which is dependent upon the capacitance and inductance values of the circuit.

Symmetry breaking in fluid dynamics: Lie group reducible motions for real fluids

Energy Technology Data Exchange (ETDEWEB)

Holm, D.D.

1976-07-01

The physics of fluids is based on certain kinematical invariance principles, which refer to coordinate systems, dimensions, and Galilean reference frames. Other, thermodynamic, symmetry principles are introduced by the material description. In the present work, the interplay between these two kinds of invariance principles is used to solve for classes of one-dimensional non-steady isentropic motions of a fluid whose equation of state is of Mie-Gruneisen type. Also, the change in profile and attenuation of weak shock waves in a dissipative medium is studied at the level of Burgers' approximation from the viewpoint of its underlying symmetry structure. The mathematical method of approach is based on the theory of infinitesimal Lie groups. Fluid motions are characterized according to inequivalent subgroups of the full invariance group of the flow description and exact group reducible solutions are presented.

Heat exchanger with intermediate evaporating and condensing fluid

International Nuclear Information System (INIS)

Fraas, A.P.

1978-01-01

A shell and tube-type heat exchanger, such as a liquid sodium-operated steam generator for use in nuclear reactors, comprises a shell containing a primary fluid tube bundle, a secondary fluid tube bundle at higher elevation, and an intermediate fluid vaporizing at the surface of the primary fluid tubes and condensing at the surface of the secondary fluid tubes

Fluid intelligence: A brief history.

Science.gov (United States)

Kent, Phillip

2017-01-01

The concept of fluid and crystallized intelligence was introduced to the psychological community approximately 75 years ago by Raymond B. Cattell, and it continues to be an area of active research and controversy. The purpose of this paper is to provide a brief overview of the origin of the concept, early efforts to define intelligence and uses of intelligence tests to address pressing social issues, and the ongoing controversies associated with fluid intelligence and the structure of intelligence. The putative neuropsychological underpinnings and neurological substrates of fluid intelligence are discussed.

Molecular thermodynamics of nonideal fluids

CERN Document Server

Lee, Lloyd L

2013-01-01

Molecular Thermodynamics of Nonideal Fluids serves as an introductory presentation for engineers to the concepts and principles behind and the advances in molecular thermodynamics of nonideal fluids. The book covers related topics such as the laws of thermodynamics; entropy; its ensembles; the different properties of the ideal gas; and the structure of liquids. Also covered in the book are topics such as integral equation theories; theories for polar fluids; solution thermodynamics; and molecular dynamics. The text is recommended for engineers who would like to be familiarized with the concept

Removal of unwanted fluid

Science.gov (United States)

Subudhi, Sudhakar; Sreenivas, K. R.; Arakeri, Jaywant H.

2013-01-01

This work is concerned with the removal of unwanted fluid through the source-sink pair. The source consists of fluid issuing out of a nozzle in the form of a jet and the sink is a pipe that is kept some distance from the source pipe. Of concern is the percentage of source fluid sucked through the sink. The experiments have been carried in a large glass water tank. The source nozzle diameter is 6 mm and the sink pipe diameter is either 10 or 20 mm. The horizontal and vertical separations and angles between these source and sink pipes are adjustable. The flow was visualized using KMnO4 dye, planer laser induced fluorescence and particle streak photographs. To obtain the effectiveness (that is percentage of source fluid entering the sink pipe), titration method is used. The velocity profiles with and without the sink were obtained using particle image velocimetry. The sink flow rate to obtain a certain effectiveness increase dramatically with lateral separation. The sink diameter and the angle between source and the sink axes don't influence effectiveness as much as the lateral separation.

Transient flows of a Burgers' fluid

International Nuclear Information System (INIS)

Khan, M.

2005-12-01

An analysis is performed to develop the analytical solutions for some unsteady magnetohydrodynamic (MHD) flows of a Burgers' fluid between two plates. A uniform magnetic field is applied transversely to the fluid motion. The exact solutions are given for three problems. Results for the velocity fields are discussed and compared with the flows of Oldroyd-B, Maxwell, second grade and Newtonian fluids. (author)

The mobility of U and Th in subduction zone fluids: an indicator of oxygen fugacity and fluid salinity

Science.gov (United States)

Bali, Enikő; Audétat, Andreas; Keppler, Hans

2011-04-01

The solubility of U and Th in aqueous solutions at P-T-conditions relevant for subduction zones was studied by trapping uraninite or thorite saturated fluids as synthetic fluid inclusions in quartz and analyzing their composition by Laser Ablation-ICPMS. Uranium is virtually insoluble in aqueous fluids at Fe-FeO buffer conditions, whereas its solubility increases both with oxygen fugacity and with salinity to 960 ppm at 26.1 kbar, Re-ReO2 buffer conditions and 14.1 wt% NaCl in the fluid. At 26.1 kbar and 800°C, uranium solubility can be reproduced by the equation: log {{U}} = 2.681 + 0.1433log f{{O}}2 + 0.594{{Cl,}} where fO2 is the oxygen fugacity, and Cl is the chlorine content of the fluid in molality. In contrast, Th solubility is generally low (uranium increases strongly both with oxygen fugacity and with salinity. We show that reducing or NaCl-free fluids cannot produce primitive arc magmas with U/Th ratio higher than MORB. However, the dissolution of several wt% of oxidized, saline fluids in arc melts can produce U/Th ratios several times higher than in MORB. We suggest that observed U/Th ratios in arc magmas provide tight constraints on both the salinity and the oxidation state of subduction zone fluids.

Supercritical fluids in ionic liquids

NARCIS (Netherlands)

Kroon, M.C.; Peters, C.J.; Plechkova, N.V.; Seddon, K.R.

2014-01-01

Ionic liquids and supercritical fluids are both alternative environmentally benign solvents, but their properties are very different. Ionic liquids are non-volatile but often considered highly polar compounds, whereas supercritical fluids are non-polar but highly volatile compounds. The combination

Fluid-mediated redox transfer in subduction zones: Measuring the intrinsic fO2 of slab fluids in the lab

Science.gov (United States)

Iacovino, K.; Till, C. B.

2017-12-01

It is widely observed that arc magmas are the most oxidized magmas on Earth. One frequently cited explanation calls on the flux of aqueous fluid from the highly oxidized down-going slab to catalyze sub-arc mantle melting and impose a highly oxidized redox signature on the mantle wedge. Fluid inclusions from sub-arc mantle xenoliths provide evidence that "slab fluids" may be highly oxidizing (fO2 QFM+1.5; Brandon & Draper, 1996; Frost and Ballhaus, 1998), but for decades, determination of the precise reactive mechanism potentially responsible for the transfer of O2 from slab to mantle has been elusive. Pure H2O has been shown to have insufficient oxidizing capacity to affect mantle redox, but H2O-rich fluids may facilitate the mobilization of Fe3+ or other multivalent cations and/or O2 transfer via the reduction of sulfate, particularly if such fluids are hypersaline. Here we present the first results from experiments designed to investigate fluid-mediated element transfer, including redox reactions, at the slab-mantle interface. These data include the first direct measurements of the intrinsic oxygen fugacity of fluids released during slab dehydration using sliding binary alloy redox sensors. Experiments were performed on natural Fe3+-bearing antigorite serpentinite at 1-2 GPa and 800°C in a piston cylinder at Arizona State University, analogous to conditions in a subducting slab and sufficient to cause the breakdown of starting material into forsteritic olivine, Mg-rich clinopyroxene, magnetite, and aqueous fluid. Experimental time series allow for the detection of (and correction for) any buffering effect on the sample by the experimental assembly. Initial results indicate that the dehydration of sulfur-free antigorite serpentinite can generate fluids with fO2 several orders of magnitude above that of MORB mantle and similar to those observed in natural sub-arc fluid inclusions. Careful measurements of the chemistry of fluid and solid run products will elucidate

Immunotherapy With Magentorheologic Fluids

Science.gov (United States)

2011-08-01

anti-tumor effects are weakened by removal of the tumor antigen pool (i.e. surgery) or use of cytoreductive and immunosuppressive therapies (i.e...particles were injected as magneto -rheological fluid (MRF) into an orthotopic primary breast cancer and followed by application of a magnetic field to...SUBJECT TERMS MRF: Magneto -rehological fluid iron particles, IT: immunotherapy, necrotic death, DCs: dendritic cells, cytokines, chemokines

Fluorine concentrations of ore fluids in the Illinois-Kentucky district: Evidence from SEM-EDS analysis of fluid inclusion decrepitates

Science.gov (United States)

Kenderes, Stuart M.; Appold, Martin S.

2017-08-01

The Illinois-Kentucky district is an atypical occurrence of Mississippi Valley-type (MVT) mineralization that consists predominantly of fluorite rather than metal sulfide minerals. A long-standing assumption for the predominance of fluorite in the Illinois-Kentucky district is that the ore fluids there were anomalously rich in dissolved fluorine compared to typical sedimentary brines and other MVT ore fluids. This hypothesis is based on the unusual close temporal and spatial association of fluorine-rich ultramafic igneous rocks to MVT mineralization in the district, high K and Sr concentrations in the igneous rocks and in MVT ore-hosted fluid inclusions, a significant mantle 3He/4He component in ore-hosted fluid inclusions, and reaction path models that show titration of a HF-rich fluid into sedimentary brine is capable of producing a fluorite-dominated MVT ore mineral assemblage. The purpose of the present study was to test this hypothesis more directly by determining the fluorine concentration of the Illinois-Kentucky ore fluid through SEM-EDS analysis of evaporative solute mounds resulting from thermal decrepitation of fluid inclusions hosted in sphalerite. All 26 evaporative solute mounds from Illinois-Kentucky sphalerite samples analyzed contained detectable concentrations of fluorine of 1-4 weight percent. Based on calibration to standard solutions and previously published fluid inclusion major element concentrations, these solute mound fluorine concentrations correspond to fluid inclusion fluorine concentrations of about 680-4300 ppm, indicating that the Illinois-Kentucky ore fluids were quite rich in fluorine compared to typical sedimentary brines, which have fluorine concentrations mainly on the order of 1's to 10's of ppm. In contrast, solute mounds from sphalerite-hosted fluid inclusions from the Tri-State district did not contain fluorine in excess of the detection limit. The detection limit equates to an aqueous fluorine concentration between 87 and

Hydrodynamic 'memory' of binary fluid mixtures

International Nuclear Information System (INIS)

Kalashnik, M. V.; Ingel, L. Kh.

2006-01-01

A theoretical analysis is presented of hydrostatic adjustment in a two-component fluid system, such as seawater stratified with respect to temperature and salinity. Both linear approximation and nonlinear problem are investigated. It is shown that scenarios of relaxation to a hydrostatically balanced state in binary fluid mixtures may substantially differ from hydrostatic adjustment in fluids that can be stratified only with respect to temperature. In particular, inviscid two-component fluids have 'memory': a horizontally nonuniform disturbance in the initial temperature or salinity distribution does not vanish even at the final stage, transforming into a persistent thermohaline 'trace.' Despite stability of density stratification and convective stability of the fluid system by all known criteria, an initial temperature disturbance may not decay and may even increase in amplitude. Moreover, its sign may change (depending on the relative contributions of temperature and salinity to stable background density stratification). Hydrostatic adjustment may involve development of discontinuous distributions from smooth initial temperature or concentration distributions. These properties of two-component fluids explain, in particular, the occurrence of persistent horizontally or vertically nonuniform temperature and salinity distributions in the ocean, including discontinuous ones

Fluid structure interaction in tube bundles

International Nuclear Information System (INIS)

Brochard, D.; Jedrzejewski, F.; Gibert, R.J.

1995-01-01

A lot of industrial components contain tube bundles immersed in a fluid. The mechanical analysis of such systems requires the study of the fluid structure interaction in the tube bundle. Simplified methods, based on homogenization methods, have been developed to analyse such phenomenon and have been validated through experimental results. Generally, these methods consider only the fluid motion in a plan normal to the bundle axis. This paper will analyse, in a first part, the fluid structure interaction in a tube bundle through a 2D finite element model representing the bundle cross section. The influence of various parameters like the bundle size, and the bundle confinement will be studied. These results will be then compared with results from homogenization methods. Finally, the influence of the 3D fluid motion will be investigated, in using simplified methods. (authors). 11 refs., 12 figs., 2 tabs

Bubble dynamics equations in Newton fluid

International Nuclear Information System (INIS)

Xiao, J

2008-01-01

For the high-speed flow of Newton fluid, bubble is produced and expanded when it moves toward the surface of fluid. Bubble dynamics is a very important research field to understand the intrinsic feature of bubble production and motion. This research formulates the bubble expansion by expansion-local rotation transformation, which can be calculated by the measured velocity field. Then, the related dynamic equations are established to describe the interaction between the fluid and the bubble. The research shows that the bubble production condition can be expressed by critical vortex value and fluid pressure; and the bubble expansion rate can be obtained by solving the non-linear dynamic equation of bubble motion. The results may help the related research as it shows a special kind of fluid motion in theoretic sense. As an application example, the nanofiber radium-voltage relation and threshold voltage-surface tension relation in electrospinning process are discussed

Fluid-bed process for SYNROC production

International Nuclear Information System (INIS)

Ackerman, F.J.; Grens, J.Z.; Ryerson, F.J.; Hoenig, C.L.; Bazan, F.; Peters, P.E.; Smith, R.; Campbell, J.H.

1983-01-01

SYNROC is a titanate-based ceramic waste developed for the immobilization of high-level nuclear reactor waste. Lawrence Livermore National Laboratory (LLNL) has investigated a fluid-bed technique for the large-scale production of SYNROC precursor powders. Making SYNROC in a fluid bed permits slurry drying, calcination and reduction-oxidation reactions to be carried out in a single unit. We present the results of SYNROC fluid-bed studies from two fluid-bed units 10 cm in diameter: an internally heated fluid-bed unit developed by Exxon Idaho and an externally heated unit constructed at LLNL. Bed operation over a range of temperatures, feed rates, fluidizing rates, and redox conditions indicate that SYNROC powders of a high density and a uniform particle size can be produced. These powders facilitate the densification step and yield dense ceramics (greater than 95% theoretical density) with well-developed phases and low leaching rates

Microbial Metabolism in Serpentinite Fluids

Science.gov (United States)

Crespo-Medina, M.; Brazelton, W. J.; Twing, K. I.; Kubo, M.; Hoehler, T. M.; Schrenk, M. O.

2013-12-01

Serpentinization is the process in which ultramafic rocks, characteristic of the upper mantle, react with water liberating mantle carbon and reducing power to potenially support chemosynthetic microbial communities. These communities may be important mediators of carbon and energy exchange between the deep Earth and the surface biosphere. Our work focuses on the Coast Range Ophiolite Microbial Observatory (CROMO) in Northern California where subsurface fluids are accessible through a series of wells. Preliminary analyses indicate that the highly basic fluids (pH 9-12) have low microbial diversity, but there is limited knowledge about the metabolic capabilities of these communties. Metagenomic data from similar serpentine environments [1] have identified Betaproteobacteria belonging to the order Burkholderiales and Gram-positive bacteria from the order Clostridiales as key components of the serpentine microbiome. In an effort to better characterize the microbial community, metabolism, and geochemistry at CROMO, fluids from two representative wells (N08B and CSWold) were sampled during recent field campaigns. Geochemical characterization of the fluids includes measurements of dissolved gases (H2, CO, CH4), dissolved inorganic and organic carbon, volatile fatty acids, and nutrients. The wells selected can be differentiated in that N08B had higher pH (10-11), lower dissolved oxygen, and cell counts ranging from 105-106 cells mL-1 of fluid, with an abundance of the betaproteobacterium Hydrogenophaga. In contrast, fluids from CSWold have slightly lower pH (9-9.5), DO, and conductivity, as well as higher TDN and TDP. CSWold fluid is also characterized for having lower cell counts (~103 cells mL-1) and an abundance of Dethiobacter, a taxon within the phylum Clostridiales. Microcosm experiments were conducted with the purpose of monitoring carbon fixation, methanotrophy and metabolism of small organic compounds, such as acetate and formate, while tracing changes in fluid

Minimizing the Fluid Used to Induce Fracturing

Science.gov (United States)

Boyle, E. J.

2015-12-01

The less fluid injected to induce fracturing means less fluid needing to be produced before gas is produced. One method is to inject as fast as possible until the desired fracture length is obtained. Presented is an alternative injection strategy derived by applying optimal system control theory to the macroscopic mass balance. The picture is that the fracture is constant in aperture, fluid is injected at a controlled rate at the near end, and the fracture unzips at the far end until the desired length is obtained. The velocity of the fluid is governed by Darcy's law with larger permeability for flow along the fracture length. Fracture growth is monitored through micro-seismicity. Since the fluid is assumed to be incompressible, the rate at which fluid is injected is balanced by rate of fracture growth and rate of loss to bounding rock. Minimizing injected fluid loss to the bounding rock is the same as minimizing total injected fluid How to change the injection rate so as to minimize the total injected fluid is a problem in optimal control. For a given total length, the variation of the injected rate is determined by variations in overall time needed to obtain the desired fracture length, the length at any time, and the rate at which the fracture is growing at that time. Optimal control theory leads to a boundary condition and an ordinary differential equation in time whose solution is an injection protocol that minimizes the fluid used under the stated assumptions. That method is to monitor the rate at which the square of the fracture length is growing and adjust the injection rate proportionately.

Magnetohydrodynamic motion of a two-fluid plasma

Science.gov (United States)

Burby, J. W.

2017-08-01

The two-fluid Maxwell system couples frictionless electrons and ion fluids via Maxwell's equations. When the frequencies of light waves, Langmuir waves, and single-particle cyclotron motion are scaled to be asymptotically large, the two-fluid Maxwell system becomes a fast-slow dynamical system. This fast-slow system admits a formally exact single-fluid closure that may be computed systematically with any desired order of accuracy through the use of a functional partial differential equation. In the leading order approximation, the closure reproduces magnetohydrodynamics (MHD). Higher order truncations of the closure give an infinite hierarchy of extended MHD models that allow for arbitrary mass ratio, as well as perturbative deviations from charge neutrality. The closure is interpreted geometrically as an invariant slow manifold in the infinite-dimensional two-fluid phase space, on which two-fluid motions are free of high-frequency oscillations. This perspective shows that the full closure inherits a Hamiltonian structure from the two-fluid theory. By employing infinite-dimensional Lie transforms, the Poisson bracket for the all-order closure may be obtained in the closed form. Thus, conservative truncations of the single-fluid closure may be obtained by simply truncating the single-fluid Hamiltonian. Moreover, the closed-form expression for the all-order bracket gives explicit expressions for a number of the full closure's conservation laws. Notably, the full closure, as well as any of its Hamiltonian truncations, admits a pair of independent circulation invariants.

MRI of subdural fluid collections in infants

International Nuclear Information System (INIS)

Fukushima, Tsuneyuki; Takagi, Takuji; Nagai, Hajime; Banno, Tatsuo

1988-01-01

Twenty cases of subdural fluid collectioin in infants were examined by MRI (0.5 Tesla). The findings of MRI were classified into 3 groups as follows: Group I: Blood component is observed in the entire subdural fluid (4 cases, 20 %). Group II: Blood component is observed in a part of the subdural fluid (4 cases, 20 %). Group III: Subdural fluid consists of pure CSF (12 cases, 60 %). In general, operative treatment should be considered for cases which have blood components in the subdural space and/or symptoms and signs of increased ICP. In group I, operation was performed on 2 cases (50 %). In group II, subdural fluid collections were associated with dilated subarachnoid spaces and 2 cases were operated on in this group (50 %). In group III, only one case was operated on (8.3 %) and subdural fluid collections disappeared spontaneously in 4 cases of this group. The precise anatomical location of subdural fluid collections could not be decided in several cases even by MRI. The cases which had blood components, tended to demonstrate membranes frequently on MRI. However, the existence of blood components did not affect the DQ S significantly. The prognosis of subdural fluid collection is supposedly related to the degree of preexistent brain damage. (author)

Biodegradability of unused lubricating brake fluids in fresh and ...

African Journals Online (AJOL)

The biodegradability of four unused lubricating brake fluids (Total brake fluid, Allied brake fluid, Oando brake fluid and Ate brake fluid) was carried out in fresh and marine water obtained from Isiokpo stream and Bonny river of the Niger Delta, South South Nigeria. Biodegradability, of the brake fluids were obtained after a 56 ...

Thermodynamic properties of cryogenic fluids

CERN Document Server

Leachman, Jacob; Lemmon, Eric; Penoncello, Steven

2017-01-01

This update to a classic reference text provides practising engineers and scientists with accurate thermophysical property data for cryogenic fluids. The equations for fifteen important cryogenic fluids are presented in a basic format, accompanied by pressure-enthalpy and temperature-entropy charts and tables of thermodynamic properties. It begins with a chapter introducing the thermodynamic relations and functional forms for equations of state, and goes on to describe the requirements for thermodynamic property formulations, needed for the complete definition of the thermodynamic properties of a fluid. The core of the book comprises extensive data tables and charts for the most commonly-encountered cryogenic fluids. This new edition sees significant updates to the data presented for air, argon, carbon monoxide, deuterium, ethane, helium, hydrogen, krypton, nitrogen and xenon. The book supports and complements NIST’s REFPROP - an interactive database and tool for the calculation of thermodynamic propertie...

Mesoscopic model for binary fluids

Science.gov (United States)

Echeverria, C.; Tucci, K.; Alvarez-Llamoza, O.; Orozco-Guillén, E. E.; Morales, M.; Cosenza, M. G.

2017-10-01

We propose a model for studying binary fluids based on the mesoscopic molecular simulation technique known as multiparticle collision, where the space and state variables are continuous, and time is discrete. We include a repulsion rule to simulate segregation processes that does not require calculation of the interaction forces between particles, so binary fluids can be described on a mesoscopic scale. The model is conceptually simple and computationally efficient; it maintains Galilean invariance and conserves the mass and energy in the system at the micro- and macro-scale, whereas momentum is conserved globally. For a wide range of temperatures and densities, the model yields results in good agreement with the known properties of binary fluids, such as the density profile, interface width, phase separation, and phase growth. We also apply the model to the study of binary fluids in crowded environments with consistent results.

Euler's fluid equations: Optimal control vs optimization

International Nuclear Information System (INIS)

Holm, Darryl D.

2009-01-01

An optimization method used in image-processing (metamorphosis) is found to imply Euler's equations for incompressible flow of an inviscid fluid, without requiring that the Lagrangian particle labels exactly follow the flow lines of the Eulerian velocity vector field. Thus, an optimal control problem and an optimization problem for incompressible ideal fluid flow both yield the same Euler fluid equations, although their Lagrangian parcel dynamics are different. This is a result of the gauge freedom in the definition of the fluid pressure for an incompressible flow, in combination with the symmetry of fluid dynamics under relabeling of their Lagrangian coordinates. Similar ideas are also illustrated for SO(N) rigid body motion.

Fluid control structures in microfluidic devices

Science.gov (United States)

Mathies, Richard A.; Grover, William H.; Skelley, Alison; Lagally, Eric; Liu, Chung N.

2017-05-09

Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.

Apparatus and Methods for Fluid Storage and Delivery

Science.gov (United States)

Parazynski, Scott E. (Inventor); Bue, Grant C. (Inventor); Schaefbauer, Mark E. (Inventor); Urban, Kase C. (Inventor)

2014-01-01

An apparatus and method for storing and delivering fluid to a person comprises, in at least one specific embodiment, a fluid reservoir having an internal volume therein with an opening disposed through a first wall or a second wall of the fluid reservoir and located toward a first end of the fluid reservoir. A first portion of a tube can be exterior to the fluid reservoir and a second portion of the tube can be disposed through the opening and within the internal volume. At least one insulation layer can be disposed about the exterior of the first wall of the fluid reservoir. The second wall of the fluid reservoir can be configured for transferring heat from or to the internal volume or from the person. At least one baffle is disposed within the internal volume and connected to the first wall and the second wall of the fluid reservoir.

Precision Fluid Management in Continuous Renal Replacement Therapy.

Science.gov (United States)

Murugan, Raghavan; Hoste, Eric; Mehta, Ravindra L; Samoni, Sara; Ding, Xiaoqiang; Rosner, Mitchell H; Kellum, John A; Ronco, Claudio

2016-01-01

Fluid management during continuous renal replacement therapy (CRRT) in critically ill patients is a dynamic process that encompasses 3 inter-related goals: maintenance of the patency of the CRRT circuit, maintenance of plasma electrolyte and acid-base homeostasis and regulation of patient fluid balance. In this article, we report the consensus recommendations of the 2016 Acute Disease Quality Initiative XVII conference on 'Precision Fluid Management in CRRT'. We discuss the principles of fluid management, describe various prescription methods to achieve circuit integrity and introduce the concept of integrated fluid balance for tailoring fluid balance to the needs of the individual patient. We suggest that these recommendations could serve to develop the best clinical practice and standards of care for fluid management in patients undergoing CRRT. Finally, we identify and highlight areas of uncertainty in fluid management and set an agenda for future research. © 2016 S. Karger AG, Basel.

Correlation of supercritical-fluid extraction recoveries with supercritical-fluid chromatographic retention data: A fundamental study

NARCIS (Netherlands)

Lou, X.W.; Janssen, J.G.M.; Cramers, C.A.M.G.

1995-01-01

The possibility of using supercritical-fluid chromatographic retention data for examining the effects of operational parameters, such as pressure and flow rate, on the extraction characteristics in supercritical-fluid extraction (SFE) was investigated. A model was derived for calculating the

Three-dimensional fluid-structure interaction case study on cubical fluid cavity with flexible bottom

Science.gov (United States)

Ghelardi, Stefano; Rizzo, Cesare; Villa, Diego

2017-12-01

In this paper, we report our study on a numerical fluid-structure interaction problem originally presented by Mok et al. (2001) in two dimensions and later studied in three dimensions by Valdés Vazquez (2007), Lombardi (2012), and Trimarchi (2012). We focus on a 3D test case in which we evaluated the sensitivity of several input parameters on the fluid and structural results. In particular, this analysis provides a starting point from which we can look deeper into specific aspects of these simulations and analyze more realistic cases, e.g., in sails design. In this study, using the commercial software ADINA™, we addressed a well-known unsteadiness problem comprising a square box representing the fluid domain with a flexible bottom modeled with structural shell elements. We compared data from previously published work whose authors used the same numerical approach, i.e., a partitioned approach coupling a finite volume solver (for the fluid domain) and a finite element solver (for the solid domain). Specifically, we established several benchmarks and made comparisons with respect to fluid and solid meshes, structural element types, and structural damping, as well as solution algorithms. Moreover, we compared our method with a monolithic finite element solution method. Our comparisons of new and old results provide an outline of best practices for such simulations.

Fluid conductivity sensor

International Nuclear Information System (INIS)

Miller, F. M.

1985-01-01

Apparatus for sensing the electrical conductivity of fluid which can be used to detonate an electro explosive device for operating a release mechanism for uncoupling a parachute canopy from its load upon landing in water. An operating network connected to an ignition capacitor and to a conductivity sensing circuit and connected in controlling relation to a semiconductor switch has a voltage independent portion which controls the time at which the semiconductor switch is closed to define a discharge path to detonate the electro explosive device independent of the rate of voltage rise on the ignition capacitor. The operating network also has a voltage dependent portion which when a voltage of predetermined magnitude is developed on the conductivity sensing circuit in response to fluid not having the predetermined condition of conductivity, the voltage dependent portion closes the semiconductor switch to define the discharge path when the energy level is insufficient to detonate the electro explosive device. A regulated current source is connected in relation to the conductivity sensing circuit and to the electrodes thereof in a manner placing the circuit voltage across the electrodes when the conductivity of the fluid is below a predetermined magnitude so that the sensing circuit does not respond thereto and placing the circuit voltage across the sensing circuit when the conductivity of the fluid is greater than a predetermined magnitude. The apparatus is operated from a battery, and the electrodes are of dissimilar metals so selected and connected relative to the polarity portions of the circuit to maximize utilization of the battery output voltage

Packing frustration in dense confined fluids.

Science.gov (United States)

Nygård, Kim; Sarman, Sten; Kjellander, Roland

2014-09-07

Packing frustration for confined fluids, i.e., the incompatibility between the preferred packing of the fluid particles and the packing constraints imposed by the confining surfaces, is studied for a dense hard-sphere fluid confined between planar hard surfaces at short separations. The detailed mechanism for the frustration is investigated via an analysis of the anisotropic pair distributions of the confined fluid, as obtained from integral equation theory for inhomogeneous fluids at pair correlation level within the anisotropic Percus-Yevick approximation. By examining the mean forces that arise from interparticle collisions around the periphery of each particle in the slit, we calculate the principal components of the mean force for the density profile--each component being the sum of collisional forces on a particle's hemisphere facing either surface. The variations of these components with the slit width give rise to rather intricate changes in the layer structure between the surfaces, but, as shown in this paper, the basis of these variations can be easily understood qualitatively and often also semi-quantitatively. It is found that the ordering of the fluid is in essence governed locally by the packing constraints at each single solid-fluid interface. A simple superposition of forces due to the presence of each surface gives surprisingly good estimates of the density profiles, but there remain nontrivial confinement effects that cannot be explained by superposition, most notably the magnitude of the excess adsorption of particles in the slit relative to bulk.

Flow of two stratified fluids in an open channel with addition of fluids along the channel length

International Nuclear Information System (INIS)

Gardner, G.C.

1980-01-01

It is shown that two stably stratified fluids flowing in an open channel have two critical flow conditions. The one at higher flowrates is equivalent to the choked flow condition of a single fluid over a broad-crested weir, when the Froude number is unity. The lower critical condition imposes restrictions, which define the system if fluids are added progressively along the channel length and the flowrates increase from low to high values. However, if the flowrate does not become sufficiently large to pass through the lower critical condition, this condition will then define a form of choking, which again determines the system. It is shown that an important special case, with the proportional flowrates of the two fluids kept constant, has an analytical solution in which the relative depths of the fluids is a constant along the channel. Other systems must be solved numerically. (orig.)

Fluid observers and tilting cosmology

International Nuclear Information System (INIS)

Coley, A A; Hervik, S; Lim, W C

2006-01-01

We study perfect fluid cosmological models with a constant equation of state parameter γ in which there are two naturally defined timelike congruences, a geometrically defined geodesic congruence and a non-geodesic fluid congruence. We establish an appropriate set of boost formulae relating the physical variables, and consequently the observed quantities, in the two frames. We study expanding spatially homogeneous tilted perfect fluid models, with an emphasis on future evolution with extreme tilt. We show that for ultra-radiative equations of state (i.e. γ > 4/3), generically the tilt becomes extreme at late times and the fluid observers will reach infinite expansion within a finite proper time and experience a singularity similar to that of the big rip. In addition, we show that for sub-radiative equations of state (i.e. γ < 4/3), the tilt can become extreme at late times and give rise to an effective quintessential equation of state. To establish the connection with phantom cosmology and quintessence, we calculate the effective equation of state in the models under consideration and we determine the future asymptotic behaviour of the tilting models in the fluid frame variables using the boost formulae. We also discuss spatially inhomogeneous models and tilting spatially homogeneous models with a cosmological constant

Anthropometric changes and fluid shifts

Science.gov (United States)

Thornton, W. E.; Hoffler, G. W.; Rummel, J. A.

1974-01-01

Several observations of body size, shape, posture, and configuration were made to document changes resulting from direct effects of weightlessness during the Skylab 4 mission. After the crewmen were placed in orbit, a number of anatomical and anthropometric changes occurred including a straightening of the thoracolumbar spine, a general decrease in truncal girth, and an increase in height. By the time of the earliest in-flight measurement on mission day 3, all crewmen had lost more than two liters of extravascular fluid from the calf and thigh. The puffy facies, the bird legs effect, the engorgement of upper body veins, and the reduced volume of lower body veins were all documented with photographs. Center-of-mass measurements confirmed a fluid shift cephalad. This shift remained throughout the mission until recovery, when a sharp reversal occurred; a major portion of the reversal was completed in a few hours. The anatomical changes are of considerable scientific interest and of import to the human factors design engineer, but the shifts of blood and extravascular fluid are of more consequence. It is hypothesized that the driving force for the fluid shift is the intrinsic and unopposed lower limb elasticity that forces venous blood and then other fluid cephalad.

Amniotic fluid inflammatory cytokines

DEFF Research Database (Denmark)

Abdallah, Morsi; Larsen, Nanna; Grove, Jakob

2013-01-01

The aim of the study was to analyze cytokine profiles in amniotic fluid (AF) samples of children developing autism spectrum disorders (ASD) and controls, adjusting for maternal autoimmune disorders and maternal infections during pregnancy.......The aim of the study was to analyze cytokine profiles in amniotic fluid (AF) samples of children developing autism spectrum disorders (ASD) and controls, adjusting for maternal autoimmune disorders and maternal infections during pregnancy....

AqSo_NaCl: Computer program to calculate p-T-V-x properties in the H2O-NaCl fluid system applied to fluid inclusion research and pore fluid calculation

Science.gov (United States)

Bakker, Ronald J.

2018-06-01

The program AqSo_NaCl has been developed to calculate pressure - molar volume - temperature - composition (p-V-T-x) properties, enthalpy, and heat capacity of the binary H2O-NaCl system. The algorithms are designed in BASIC within the Xojo programming environment, and can be operated as stand-alone project with Macintosh-, Windows-, and Unix-based operating systems. A series of ten self-instructive interfaces (modules) are developed to calculate fluid inclusion properties and pore fluid properties. The modules may be used to calculate properties of pure NaCl, the halite-liquidus, the halite-vapourus, dew-point and bubble-point curves (liquid-vapour), critical point, and SLV solid-liquid-vapour curves at temperatures above 0.1 °C (with halite) and below 0.1 °C (with ice or hydrohalite). Isochores of homogeneous fluids and unmixed fluids in a closed system can be calculated and exported to a.txt file. Isochores calculated for fluid inclusions can be corrected according to the volumetric properties of quartz. Microthermometric data, i.e. dissolution temperatures and homogenization temperatures, can be used to calculated bulk fluid properties of fluid inclusions. Alternatively, in the absence of total homogenization temperature the volume fraction of the liquid phase in fluid inclusions can be used to obtain bulk properties.

Solving problems in fluid mechanics. Vol. 1

International Nuclear Information System (INIS)

Douglas, J.F.

1986-01-01

Fluid mechanics is that part of applied mechanics concerned with the statics and dynamics of liquids and gases. The presentation is in a pedagogically sound question-and-answer format, which includes many worked examples preceding the exercises. This book which assumes only an elementary knowledge of mathematics and mechanics, offers a clear exposition of topics including hydrostatics, fluid pressure and the stability of floating bodies, fluid motion, flow measurement, pipelines, open channel flow, and fluid friction

Hierarchical Bayesian Modeling of Fluid-Induced Seismicity

Science.gov (United States)

Broccardo, M.; Mignan, A.; Wiemer, S.; Stojadinovic, B.; Giardini, D.

2017-11-01

In this study, we present a Bayesian hierarchical framework to model fluid-induced seismicity. The framework is based on a nonhomogeneous Poisson process with a fluid-induced seismicity rate proportional to the rate of injected fluid. The fluid-induced seismicity rate model depends upon a set of physically meaningful parameters and has been validated for six fluid-induced case studies. In line with the vision of hierarchical Bayesian modeling, the rate parameters are considered as random variables. We develop both the Bayesian inference and updating rules, which are used to develop a probabilistic forecasting model. We tested the Basel 2006 fluid-induced seismic case study to prove that the hierarchical Bayesian model offers a suitable framework to coherently encode both epistemic uncertainty and aleatory variability. Moreover, it provides a robust and consistent short-term seismic forecasting model suitable for online risk quantification and mitigation.

Evolutionary space station fluids management strategies

Science.gov (United States)

1989-01-01

Results are summarized for an 11-month study to define fluid storage and handling strategies and requirements for various specific mission case studies and their associated design impacts on the Space Station. There are a variety of fluid users which require a variety of fluids and use rates. Also, the cryogenic propellants required for NASA's STV, Planetary, and Code Z missions are enormous. The storage methods must accommodate fluids ranging from a high pressure gas or supercritical state fluid to a sub-cooled liquid (and superfluid helium). These requirements begin in the year 1994, reach a maximum of nearly 1800 metric tons in the year 2004, and trail off to the year 2018, as currently planned. It is conceivable that the cryogenic propellant needs for the STV and/or Lunar mission models will be met by LTCSF LH2/LO2 tanksets attached to the SS truss structure. Concepts and corresponding transfer and delivery operations have been presented for STV propellant provisioning from the SS. A growth orbit maneuvering vehicle (OMV) and associated servicing capability will be required to move tanksets from delivery launch vehicles to the SS or co-orbiting platforms. Also, appropriate changes to the software used for OMV operation are necessary to allow for the combined operation of the growth OMV. To support fluid management activities at the Space Station for the experimental payloads and propellant provisioning, there must be truss structure space allocated for fluid carriers and propellant tanksets, and substantial beam strengthening may be required. The Station must have two Mobile Remote Manipulator Systems (MRMS) and the growth OMV propellant handling operations for the STV at the SS. Propellant needs for the Planetary Initiatives and Code Z mission models will most likely be provided by co-orbiting propellant platform(s). Space Station impacts for Code Z mission fluid management activities will be minimal.

Fluid supplementation for neonatal unconjugated hyperbilirubinaemia.

Science.gov (United States)

Lai, Nai Ming; Ahmad Kamar, Azanna; Choo, Yao Mun; Kong, Juin Yee; Ngim, Chin Fang

2017-08-01

Neonatal hyperbilirubinaemia is a common problem which carries a risk of neurotoxicity. Certain infants who have hyperbilirubinaemia develop bilirubin encephalopathy and kernicterus which may lead to long-term disability. Phototherapy is currently the mainstay of treatment for neonatal hyperbilirubinaemia. Among the adjunctive measures to compliment the effects of phototherapy, fluid supplementation has been proposed to reduce serum bilirubin levels. The mechanism of action proposed includes direct dilutional effects of intravenous (IV) fluids, or enhancement of peristalsis to reduce enterohepatic circulation by oral fluid supplementation. To assess the risks and benefits of fluid supplementation compared to standard fluid management in term and preterm newborn infants with unconjugated hyperbilirubinaemia who require phototherapy. We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 5), MEDLINE via PubMed (1966 to 7 June 2017), Embase (1980 to 7 June 2017), and CINAHL (1982 to 7 June 2017). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. We included randomised controlled trials that compared fluid supplementation against no fluid supplementation, or one form of fluid supplementation against another. We extracted data using the standard methods of the Cochrane Neonatal Review Group using the Covidence platform. Two review authors independently assessed the eligibility and risk of bias of the retrieved records. We expressed our results using mean difference (MD), risk difference (RD), and risk ratio (RR) with 95% confidence intervals (CIs). Out of 1449 articles screened, seven studies were included. Three articles were awaiting classification, among them, two completed trials identified from the trial registry appeared to be unpublished so far.There were

Annual review of fluid mechanics. Volume 23

International Nuclear Information System (INIS)

Lumley, J.L.; Van Dyke, M.; Reed, H.L.

1991-01-01

Recent advances in theoretical, experimental, and computational fluid mechanics are discussed in a collection of annual review essays. Topics addressed include Lagrangian ocean studies, drag reduction in nature, the hydraulics of rotating strait and sill flow, analytical methods for the development of Reynolds-stress closures in turbulence, and exact solutions of the Navier-Stokes equations. Consideration is given to the theory of hurricanes, flow phenomena in CVD of thin films, particle-imaging techniques for experimental fluid mechanics, symmetry and symmetry-breaking bifurcations in fluid dynamics, turbulent mixing in stratified fluids, numerical simulation of transition in wall-bounded shear flows, fractals and multifractals in fluid turbulence, and coherent motions in the turbulent boundary layer

An investigation of dentinal fluid flow in dental pulp during food mastication: simulation of fluid-structure interaction.

Science.gov (United States)

Su, Kuo-Chih; Chuang, Shu-Fen; Ng, Eddie Yin-Kwee; Chang, Chih-Han

2014-06-01

This study uses fluid-structure interaction (FSI) simulation to investigate the relationship between the dentinal fluid flow in the dental pulp of a tooth and the elastic modulus of masticated food particles and to investigate the effects of chewing rate on fluid flow in the dental pulp. Three-dimensional simulation models of a premolar tooth (enamel, dentine, pulp, periodontal ligament, cortical bone, and cancellous bone) and food particle were created. Food particles with elastic modulus of 2,000 and 10,000 MPa were used, respectively. The external displacement loading (5 μm) was gradually directed to the food particle surface for 1 and 0.1 s, respectively, to simulate the chewing of food particles. The displacement and stress on tooth structure and fluid flow in the dental pulp were selected as evaluation indices. The results show that masticating food with a high elastic modulus results in high stress and deformation in the tooth structure, causing faster dentinal fluid flow in the pulp in comparison with that obtained with soft food. In addition, fast chewing of hard food particles can induce faster fluid flow in the pulp, which may result in dental pain. FSI analysis is shown to be a useful tool for investigating dental biomechanics during food mastication. FSI simulation can be used to predict intrapulpal fluid flow in dental pulp; this information may provide the clinician with important concept in dental biomechanics during food mastication.

Fluid-structure interaction of submerged structures

International Nuclear Information System (INIS)

Tang, H.T.; Becker, E.B.; Taylor, L.M.

1979-01-01

The purpose of the paper is to investigate fluid-structure interaction (FSI) of submerged structures in a confined fluid-structure system. Our particular interest is the load experienced by a rigid submerged structure subject to a pressure excitation in a fluid domain bounded by a structure which is either flexible or rigid. The objective is to see whether the load experienced by the submerged structure will be influenced by its confinement conditions. This investigation is intended to provide insight into the characteristics of FSI and answer the question as to whether one can obtain FSI independent data by constructing a small scale rigid submerged structure inside a flexible fluid-structure system. (orig.)

Relativistic elasticity of stationary fluid branes

Science.gov (United States)

Armas, Jay; Obers, Niels A.

2013-02-01

Fluid mechanics can be formulated on dynamical surfaces of arbitrary codimension embedded in a background space-time. This has been the main object of study of the blackfold approach in which the emphasis has primarily been on stationary fluid configurations. Motivated by this approach we show under certain conditions that a given stationary fluid configuration living on a dynamical surface of vanishing thickness and satisfying locally the first law of thermodynamics will behave like an elastic brane when the surface is subject to small deformations. These results, which are independent of the number of space-time dimensions and of the fluid arising from a gravitational dual, reveal the (electro)elastic character of (charged) black branes when considering extrinsic perturbations.

International Conference on Mathematical Fluid Dynamics

CERN Document Server

Suzuki, Yukihito

2016-01-01

This volume presents original papers ranging from an experimental study on cavitation jets to an up-to-date mathematical analysis of the Navier-Stokes equations for free boundary problems, reflecting topics featured at the International Conference on Mathematical Fluid Dynamics, Present and Future, held 11–14 November 2014 at Waseda University in Tokyo. The contributions address subjects in one- and two-phase fluid flows, including cavitation, liquid crystal flows, plasma flows, and blood flows. Written by internationally respected experts, these papers highlight the connections between mathematical, experimental, and computational fluid dynamics. The book is aimed at a wide readership in mathematics and engineering, including researchers and graduate students interested in mathematical fluid dynamics.

Mechanics of couple-stress fluid coatings

Science.gov (United States)

Waxman, A. M.

1982-01-01

The formal development of a theory of viscoelastic surface fluids with bending resistance - their kinematics, dynamics, and rheology are discussed. It is relevant to the mechanics of fluid drops and jets coated by a thin layer of immiscible fluid with rather general rheology. This approach unifies the hydrodynamics of two-dimensional fluids with the mechanics of an elastic shell in the spirit of a Cosserat continuum. There are three distinct facets to the formulation of surface continuum mechanics. Outlined are the important ideas and results associated with each: the kinematics of evolving surface geometries, the conservation laws governing the mechanics of surface continua, and the rheological equations of state governing the surface stress and moment tensors.

Geometrical approach to fluid models

International Nuclear Information System (INIS)

Kuvshinov, B.N.; Schep, T.J.

1997-01-01

Differential geometry based upon the Cartan calculus of differential forms is applied to investigate invariant properties of equations that describe the motion of continuous media. The main feature of this approach is that physical quantities are treated as geometrical objects. The geometrical notion of invariance is introduced in terms of Lie derivatives and a general procedure for the construction of local and integral fluid invariants is presented. The solutions of the equations for invariant fields can be written in terms of Lagrange variables. A generalization of the Hamiltonian formalism for finite-dimensional systems to continuous media is proposed. Analogously to finite-dimensional systems, Hamiltonian fluids are introduced as systems that annihilate an exact two-form. It is shown that Euler and ideal, charged fluids satisfy this local definition of a Hamiltonian structure. A new class of scalar invariants of Hamiltonian fluids is constructed that generalizes the invariants that are related with gauge transformations and with symmetries (Noether). copyright 1997 American Institute of Physics

Fluid mechanics of heart valves.

Science.gov (United States)

Yoganathan, Ajit P; He, Zhaoming; Casey Jones, S

2004-01-01

Valvular heart disease is a life-threatening disease that afflicts millions of people worldwide and leads to approximately 250,000 valve repairs and/or replacements each year. Malfunction of a native valve impairs its efficient fluid mechanic/hemodynamic performance. Artificial heart valves have been used since 1960 to replace diseased native valves and have saved millions of lives. Unfortunately, despite four decades of use, these devices are less than ideal and lead to many complications. Many of these complications/problems are directly related to the fluid mechanics associated with the various mechanical and bioprosthetic valve designs. This review focuses on the state-of-the-art experimental and computational fluid mechanics of native and prosthetic heart valves in current clinical use. The fluid dynamic performance characteristics of caged-ball, tilting-disc, bileaflet mechanical valves and porcine and pericardial stented and nonstented bioprostheic valves are reviewed. Other issues related to heart valve performance, such as biomaterials, solid mechanics, tissue mechanics, and durability, are not addressed in this review.

Fluid/structure interaction in BERDYNE (Level 4)

International Nuclear Information System (INIS)

Fox, M.J.H.

1988-02-01

A fluid-structure interaction capability has been developed for Level 4 of the finite element dynamics code BERDYNE, as part of the BERSAFE structural analysis system. This permits analysis of small amplitude free or forced vibration of systems comprising elastic structural components and inviscid volumes of possibly compressible fluid. Free fluid surfaces under the influence of gravity may be present. The formulation chosen uses the rigid walled fluid modes, calculated in a preliminary stage, as a basis for description of the coupled system, providing symmetric system matrices for which efficient solution procedures are available. The inclusion of the fluid modal variables within the system matrices is carried out through the use of the BERDYNE 'substructuring' feature, which allows the inclusion of very general 'super-elements' among the normal structural elements. The program also has a seismic analysis capability, used for the analysis of fluid-structure systems subjected to a specified support acceleration time history. In this case analysis is carried out in terms of relative structural motions, but absolute fluid pressures. Application of the BERDYNE fluid/structure interaction capability to some simple test cases produced results in good agreement with results obtained by analytic or independent numerical techniques. Full instructions on the use of the facility will be included in the BERDYNE Level 4 documentation. Interim documentation for the pre-release version is available from the author. (author)

Appropriate fluid regimens to prevent bronchopulmonary dysplasia.

Science.gov (United States)

Tammela, O K

1995-01-01

Pulmonary oedema is an important problem in premature neonates with surfactant deficiency because of fluid accumulation in the lung interstitium and reduced urine output. Some retrospective reports suggest that excessive early hydration might increase the risk of bronchopulmonary dysplasia (BPD). Only three prospective studies evaluating low or conventional fluid administration regimens to very low birth weight infants have been published. According to their results no significant differences in the incidence of BPD have been shown. However, fluid restriction seems to improve the outcome of the infants because of decreased incidence of haemodynamically significant patent ductus arteriosus, necrotizing enterocolitis, pulmonary air leaks and decreased mortality. The appropriate amount of sodium in the intravenous fluids during the first days of life needs further evaluation. In tiny infants with birth weights from 500 to 800g intensive monitoring of fluid balance is essential to control the extremely high fluid losses due to evaporation. Undernutrition is a risk factor of BPD and therefore it is important to start parenteral nutrition early. The benefit of the use of colloids as volume expanders is controversial. According to some retrospective reports there might be an association with increased use of colloidal fluids during the first days of life and the development of BPD. Early excessive fluid administration might constitute a potential risk for low birth weight infants with hyaline membrane disease.(ABSTRACT TRUNCATED AT 250 WORDS)

An Analysis of Reconstituted Fluid Milk Pricing Policy

OpenAIRE

Glen D. Whipple

1983-01-01

This analysis suggests that alteration of the reconstituted fluid milk pricing provisions of federal and state milk market orders would have a substantial impact on market equilibrium. A reactive programming model of the U.S. milk market was used to simulate the effects of altered reconstituted fluid milk pricing policy. The solutions indicate that reconstituted fluid milk, as a lower cost alternative to fresh fluid milk, would make up a substantial portion of the fluid milk consumption in so...

Fluid-solid contact vessel having fluid distributors therein

Science.gov (United States)

Jones, Jr., John B.

1980-09-09

Rectangularly-shaped fluid distributors for large diameter, vertical vessels include reinforcers for high heat operation, vertical sides with gas distributing orifices and overhanging, sloped roofs. Devices are provided for cleaning the orifices from a buildup of solid deposits resulting from the reactions in the vessel.

On modifications of fluid inclusions in quartz : re-equilibration experiments and thermodynamical calculations on fluids in natural quartz

NARCIS (Netherlands)

Bakker, R.J.

1992-01-01

Fluids in rocks can be traced to great depths, and are found in crustal rocks as well as in mantle rocks. Information about the deep fluid which is obtained from fluid inclusions must be handled with care, for the way up after entrapment in a crystal is long and full of interferences at different

Predicting phase shift effects for vibrating fluid-conveying pipes due to Coriolis forces and fluid pulsation

DEFF Research Database (Denmark)

Enz, Stephanie; Thomsen, Jon Juel

2011-01-01

to improve accuracy, precision, and robustness of CFMs. A simple mathematical model of a fluid-conveying pipe is formulated and the effect of pulsating fluid flow is analyzed using a multiple time scaling perturbation analysis. The results are simple analytical predictions for the transverse pipe...... and uncontrolled during CFM operation by feedback control. The analytical predictions offer an immediate insight into how fluid pulsation affects phase shift, which is a quantity measured by CFMs to estimate the mass flow, and lead to hypotheses for more complex geometries, i.e. industrial CFMs. The validity...... displacement and approximate axial shift in vibration phase. The analytical predictions are tested against pure numerical solution using representative examples, showing good agreement. Fluid pulsations are predicted not to influence CFM accuracy, since proper signal filtering is seen to allow...

Rheology of Active Fluids

Science.gov (United States)

Saintillan, David

2018-01-01

An active fluid denotes a viscous suspension of particles, cells, or macromolecules able to convert chemical energy into mechanical work by generating stresses on the microscale. By virtue of this internal energy conversion, these systems display unusual macroscopic rheological signatures, including a curious transition to an apparent superfluid-like state where internal activity exactly compensates viscous dissipation. These behaviors are unlike those of classical complex fluids and result from the coupling of particle configurations with both externally applied flows and internally generated fluid disturbances. Focusing on the well-studied example of a suspension of microswimmers, this review summarizes recent experiments, models, and simulations in this area and highlights the critical role played by the rheological response of these active materials in a multitude of phenomena, from the enhanced transport of passive suspended objects to the emergence of spontaneous flows and collective motion.

Global dynamics of shaft lines of turbo-machineries coupled to surrounding fluids: application to the case of fluid sheets; Dynamique globale des lignes d'arbres de turbomachines couplees aux fluides environnants: application au cas des lames fluides

Energy Technology Data Exchange (ETDEWEB)

Lornage, D.

2001-12-15

Shaft lines of turbo-machineries have to stand increasing reliability, efficiency and safety requirements. A precise modeling of the rotating parts with all possible coupling has become necessary. In this context, this work aims to develop a global modeling of rotating wheel/shaft system inside a surrounding fluid in order to foresee its dynamical behaviour. The use and advantage of Eulerian, Lagrangian and mixed (arbitrary Lagrangian Eulerian - ALE) formulations is recalled first. A bibliographic synthesis of the classical techniques used in structure mechanics and of coupling techniques for rotating machines is presented. The coupling technique retained is presented. It uses fluid and structure models independently developed and validated. The structure domain is discretized by the finite-element method. The fluid domain is discretized by the finite-difference method taking into consideration the hypotheses linked with thin films. A modal base projection combined with a mesh at the fluid-structure interface allows an efficient, adaptable and evolutive coupling. Finally, the method is applied to 3 test-cases. The first two ones comprise a shaft/disc system coupled to a fluid sheet between the disc and the casing and to an hydrodynamic bearing. Both cases allow a first validation of the coupling method. The third case aims to study a structure closer to a real system made of a shaft and a wheel coupled to a fluid sheet between a flange and a casing. These three applications allow to show the trends linked with the fluid effects and the coupling between the flexible sub-parts of the structure. (J.S.)

Studies of complexity in fluid systems

Energy Technology Data Exchange (ETDEWEB)

Nagel, Sidney R.

2000-06-12

This is the final report of Grant DE-FG02-92ER25119, ''Studies of Complexity in Fluids'', we have investigated turbulence, flow in granular materials, singularities in evolution of fluid surfaces and selective withdrawal fluid flows. We have studied numerical methods for dealing with complex phenomena, and done simulations on the formation of river networks. We have also studied contact-line deposition that occurs in a drying drop.

Activation of Alkaline Irrigation Fluids in Endodontics

Directory of Open Access Journals (Sweden)

Laurence J. Walsh

2017-10-01

Full Text Available In conventional endodontic treatment, alkaline solutions of sodium hypochlorite (NaOCl and ethylenediaminetetraacetic acid (EDTA are used in combination to disinfect the root canal system and to eliminate debris and smear layers. An important concept that has emerged over recent years is the use of active physical methods for agitating these fluids to improve their penetration within areas that are not reached by endodontic instruments and to accelerate the chemical actions of these alkaline fluids against planktonic microorganisms, biofilms, soft tissue remnants and smear layers. Ultrasonic agitation and more recently pulsed lasers have emerged as two promising methods for activating endodontic irrigation fluids. Ultrasonic agitation with piezoelectric devices employs a moving tip, while laser agitation uses a stationary tip. Both methods cause cavitation, followed by implosions and shear forces which assist with debridement. Fluid streaming further enhances the activity of the fluids. While agitation enhances performance of irrigants, extrusion of fluids from the root canal during activation is a hazard that must be controlled.

46 CFR 58.30-30 - Fluid power cylinders.

Science.gov (United States)

2010-10-01

... all pneumatic power transmission systems. (b) Fluid power cylinders consisting of a container and a... 46 Shipping 2 2010-10-01 2010-10-01 false Fluid power cylinders. 58.30-30 Section 58.30-30... MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-30 Fluid power cylinders. (a) The...

Quantum field theory of fluids.

Science.gov (United States)

Gripaios, Ben; Sutherland, Dave

2015-02-20

The quantum theory of fields is largely based on studying perturbations around noninteracting, or free, field theories, which correspond to a collection of quantum-mechanical harmonic oscillators. The quantum theory of an ordinary fluid is "freer", in the sense that the noninteracting theory also contains an infinite collection of quantum-mechanical free particles, corresponding to vortex modes. By computing a variety of correlation functions at tree and loop level, we give evidence that a quantum perfect fluid can be consistently formulated as a low-energy, effective field theory. We speculate that the quantum behavior is radically different from both classical fluids and quantum fields.

Wave Interactions and Fluid Flows

Science.gov (United States)

Craik, Alex D. D.

1988-07-01

This up-to-date and comprehensive account of theory and experiment on wave-interaction phenomena covers fluids both at rest and in their shear flows. It includes, on the one hand, water waves, internal waves, and their evolution, interaction, and associated wave-driven means flow and, on the other hand, phenomena on nonlinear hydrodynamic stability, especially those leading to the onset of turbulence. This study provide a particularly valuable bridge between these two similar, yet different, classes of phenomena. It will be of value to oceanographers, meteorologists, and those working in fluid mechanics, atmospheric and planetary physics, plasma physics, aeronautics, and geophysical and astrophysical fluid dynamics.

Phase space density representations in fluid dynamics

International Nuclear Information System (INIS)

Ramshaw, J.D.

1989-01-01

Phase space density representations of inviscid fluid dynamics were recently discussed by Abarbanel and Rouhi. Here it is shown that such representations may be simply derived and interpreted by means of the Liouville equation corresponding to the dynamical system of ordinary differential equations that describes fluid particle trajectories. The Hamiltonian and Poisson bracket for the phase space density then emerge as immediate consequences of the corresponding structure of the dynamics. For barotropic fluids, this approach leads by direct construction to the formulation presented by Abarbanel and Rouhi. Extensions of this formulation to inhomogeneous incompressible fluids and to fluids in which the state equation involves an additional transported scalar variable are constructed by augmenting the single-particle dynamics and phase space to include the relevant additional variable

Introduction to mathematical fluid dynamics

CERN Document Server

Meyer, Richard E

2010-01-01

An introduction to the behavior of liquids and gases, this volume provides excellent coverage of kinematics, momentum principle, Newtonian fluid, rotating fluids, compressibility, and more. It is geared toward advanced undergraduate and graduate students of mathematics and general science, and it requires a background in calculus and vector analysis. 1971 edition.

Protein profiling reveals inter-individual protein homogeneity of arachnoid cyst fluid and high qualitative similarity to cerebrospinal fluid

Directory of Open Access Journals (Sweden)

Berle Magnus

2011-05-01

Full Text Available Abstract Background The mechanisms behind formation and filling of intracranial arachnoid cysts (AC are poorly understood. The aim of this study was to evaluate AC fluid by proteomics to gain further knowledge about ACs. Two goals were set: 1 Comparison of AC fluid from individual patients to determine whether or not temporal AC is a homogenous condition; and 2 Evaluate the protein content of a pool of AC fluid from several patients and qualitatively compare this with published protein lists of cerebrospinal fluid (CSF and plasma. Methods AC fluid from 15 patients with temporal AC was included in this study. In the AC protein comparison experiment, AC fluid from 14 patients was digested, analyzed by LC-MS/MS using a semi-quantitative label-free approach and the data were compared by principal component analysis (PCA to gain knowledge of protein homogeneity of AC. In the AC proteome evaluation experiment, AC fluid from 11 patients was pooled, digested, and fractionated by SCX chromatography prior to analysis by LC-MS/MS. Proteins identified were compared to published databases of proteins identified from CSF and plasma. AC fluid proteins not found in these two databases were experimentally searched for in lumbar CSF taken from neurologically-normal patients, by a targeted protein identification approach called MIDAS (Multiple Reaction Monitoring (MRM initiated detection and sequence analysis. Results We did not identify systematic trends or grouping of data in the AC protein comparison experiment, implying low variability between individual proteomic profiles of AC. In the AC proteome evaluation experiment, we identified 199 proteins. When compared to previously published lists of proteins identified from CSF and plasma, 15 of the AC proteins had not been reported in either of these datasets. By a targeted protein identification approach, we identified 11 of these 15 proteins in pooled CSF from neurologically-normal patients, demonstrating that

Noncommuting fields and non-Abelian fluids

International Nuclear Information System (INIS)

Jackiw, R.

2004-01-01

The original ideas about noncommuting coordinates are recalled. The connection between U(1) gauge fields defined on noncommuting coordinates and fluid mechanics is explained. Non-Abelian fluid mechanics is described

Fluid overload in the ICU: evaluation and management.

Science.gov (United States)

Claure-Del Granado, Rolando; Mehta, Ravindra L

2016-08-02

Fluid overload is frequently found in acute kidney injury patients in critical care units. Recent studies have shown the relationship of fluid overload with adverse outcomes; hence, manage and optimization of fluid balance becomes a central component of the management of critically ill patients. In critically ill patients, in order to restore cardiac output, systemic blood pressure and renal perfusion an adequate fluid resuscitation is essential. Achieving an appropriate level of volume management requires knowledge of the underlying pathophysiology, evaluation of volume status, and selection of appropriate solution for volume repletion, and maintenance and modulation of the tissue perfusion. Numerous recent studies have established a correlation between fluid overload and mortality in critically ill patients. Fluid overload recognition and assessment requires an accurate documentation of intakes and outputs; yet, there is a wide difference in how it is evaluated, reviewed and utilized. Accurate volume status evaluation is essential for appropriate therapy since errors of volume evaluation can result in either in lack of essential treatment or unnecessary fluid administration, and both scenarios are associated with increased mortality. There are several methods to evaluate fluid status; however, most of the tests currently used are fairly inaccurate. Diuretics, especially loop diuretics, remain a valid therapeutic alternative. Fluid overload refractory to medical therapy requires the application of extracorporeal therapies. In critically ill patients, fluid overload is related to increased mortality and also lead to several complications like pulmonary edema, cardiac failure, delayed wound healing, tissue breakdown, and impaired bowel function. Therefore, the evaluation of volume status is crucial in the early management of critically ill patients. Diuretics are frequently used as an initial therapy; however, due to their limited effectiveness the use of continuous

Parallel processing for fluid dynamics applications

International Nuclear Information System (INIS)

Johnson, G.M.

1989-01-01

The impact of parallel processing on computational science and, in particular, on computational fluid dynamics is growing rapidly. In this paper, particular emphasis is given to developments which have occurred within the past two years. Parallel processing is defined and the reasons for its importance in high-performance computing are reviewed. Parallel computer architectures are classified according to the number and power of their processing units, their memory, and the nature of their connection scheme. Architectures which show promise for fluid dynamics applications are emphasized. Fluid dynamics problems are examined for parallelism inherent at the physical level. CFD algorithms and their mappings onto parallel architectures are discussed. Several example are presented to document the performance of fluid dynamics applications on present-generation parallel processing devices

On the fluid mechanics of fires

Energy Technology Data Exchange (ETDEWEB)

TIESZEN,SHELDON R.

2000-02-29

Fluid mechanics research related to fire is reviewed with focus on canonical flows, multiphysics coupling aspects, experimental and numerical techniques. Fire is a low-speed, chemically-reacting, flow in which buoyancy plans an important role. Fire research has focused on two canonical flows, the reacting boundary-layer and the reacting free plume. There is rich, multi-lateral, bi-directional, coupling among fluid mechanics and scalar transport, combustion, and radiation. There is only a limited experimental fluid-mechanics database for fire due to measurement difficulties in the harsh environment, and the focus within the fire community on thermal/chemical consequences. Increasingly, computational fluid dynamics techniques are being used to provide engineering guidance on thermal/chemical consequences and to study fire phenomenology.

Study on magnetic fluid optical fiber devices for optical logic operations by characteristics of superparamagnetic nanoparticles and magnetic fluids

International Nuclear Information System (INIS)

Chieh, J. J.; Hong, C. Y.; Yang, S. Y.; Horng, H. E.; Yang, H. C.

2010-01-01

We propose two optical fiber-based schemes using two magnetic fluid optical fiber modulators in series or in parallel for optical logic signal processing and operation. Here, each magnetic fluid optical fiber modulator consists of a bare multimode fiber surrounded by magnetic fluid in which the refractive index is adjustable by applying external magnetic fields amplifying the input electrical signal to vary the transmission intensity of the optical fiber-based scheme. The physical mechanisms for the performances of the magnetic fluid optical fiber devices, such as the transmission loss related to Boolean number of the logic operation as well as the dynamic response, are studied by the characteristics of superparamagnetic nanoparticles and magnetic fluids. For example, in the dynamic response composed of the retarding and response sub-procedures except the response times of the actuation coil, the theoretical evaluation of the retarding time variation with cladding magnetic fluids length has good agreement with the experimental results.

An integrated in-line fluid characterization system for industrial applications(In-situ fluid mechanics experiments)

OpenAIRE

Johan, Wiklund; Reinhardt, Kotze; Beat, Birkhofer; Stefano, Ricci; Valentino, Meacci; Mats, Stading; Rainer, Haldenwang; SP-Technical Research Institute of Sweden; FPRC, Cape Peninsula University of Technology; Sika Services AG; Information Engineering Department - University of Florence; Information Engineering Department - University of Florence; SP-Technical Research Institute of Sweden; FPRC, Cape Peninsula University of Technology

2015-01-01

In this work we have presented the world's first commercially available embedded in-line fluids characterization system, "Flow-Viz". It has been specifically designed for the non-invasive, in-line, continuous, real-time velocity profile and rheological assessment of opaque, non-Newtonian industrial fluids. The Flow-Viz system has been successfully installed in pilot plants of international companies and used also for academic research. The technology has been applied to a wide range of fluids...

Principles of fluid management and stewardship in septic shock: it is time to consider the four D's and the four phases of fluid therapy.

Science.gov (United States)

Malbrain, Manu L N G; Van Regenmortel, Niels; Saugel, Bernd; De Tavernier, Brecht; Van Gaal, Pieter-Jan; Joannes-Boyau, Olivier; Teboul, Jean-Louis; Rice, Todd W; Mythen, Monty; Monnet, Xavier

2018-05-22

In patients with septic shock, the administration of fluids during initial hemodynamic resuscitation remains a major therapeutic challenge. We are faced with many open questions regarding the type, dose and timing of intravenous fluid administration. There are only four major indications for intravenous fluid administration: aside from resuscitation, intravenous fluids have many other uses including maintenance and replacement of total body water and electrolytes, as carriers for medications and for parenteral nutrition. In this paradigm-shifting review, we discuss different fluid management strategies including early adequate goal-directed fluid management, late conservative fluid management and late goal-directed fluid removal. In addition, we expand on the concept of the "four D's" of fluid therapy, namely drug, dosing, duration and de-escalation. During the treatment of patients with septic shock, four phases of fluid therapy should be considered in order to provide answers to four basic questions. These four phases are the resuscitation phase, the optimization phase, the stabilization phase and the evacuation phase. The four questions are "When to start intravenous fluids?", "When to stop intravenous fluids?", "When to start de-resuscitation or active fluid removal?" and finally "When to stop de-resuscitation?" In analogy to the way we handle antibiotics in critically ill patients, it is time for fluid stewardship.

Fluid transportation mechanisms by a coupled system of elastic membranes and magnetic fluids

International Nuclear Information System (INIS)

Ido, Y.; Tanaka, K.; Sugiura, Y.

2002-01-01

The basic properties of the fluid transportation mechanism that is produced by the coupled waves propagating along a thin elastic membrane covering a magnetic fluid layer in a shallow and long rectangular vessel are investigated. It is shown that the progressive magnetic field induced by the rectangular pulses generates sinusoidal vibration of the displacement of elastic membrane and makes the system work more efficiently than the magnetic field induced by the pulse-width-modulation method

Characterization of the Mechanical Properties of Electrorheological Fluids Made of Starch and Silicone Fluid

Science.gov (United States)

Vieira, Sheila Lopes; de Arruda, Antonio Celso Fonseca

In the majority of published articles on the topic, ER fluids have been studied as if they were viscous liquids. In this work, electrorheological fluids were characterized as solids and their mechanical properties were determined. The results infer that ER materials are controllably resistant to compression, tensile and shear stress, in this order of magnitude. More precisely, fluids made of starch have elasticity modulus similar to that of rubber, they have tensile strength 103 to 5×104 times lower than that of low density polyethylene (LDPE), static yield stress 4×104 to 8×105 times lower than that of acrylonitrile-butadiene-styrene terpolymer (ABS) and fatigue life similar to some polymers like polyethylene(PE) and polypropylene (PP).

[Diagnosis: synovial fluid analysis].

Science.gov (United States)

Gallo Vallejo, Francisco Javier; Giner Ruiz, Vicente

2014-01-01

Synovial fluid analysis in rheumatological diseases allows a more accurate diagnosis in some entities, mainly infectious and microcrystalline arthritis. Examination of synovial fluid in patients with osteoarthritis is useful if a differential diagnosis will be performed with other processes and to distinguish between inflammatory and non-inflammatory forms. Joint aspiration is a diagnostic and sometimes therapeutic procedure that is available to primary care physicians. Copyright © 2014 Elsevier España, S.L. All rights reserved.

Predicting and measuring fluid responsiveness with echocardiography

Directory of Open Access Journals (Sweden)

Ashley Miller

2016-06-01

Full Text Available Echocardiography is ideally suited to guide fluid resuscitation in critically ill patients. It can be used to assess fluid responsiveness by looking at the left ventricle, aortic outflow, inferior vena cava and right ventricle. Static measurements and dynamic variables based on heart–lung interactions all combine to predict and measure fluid responsiveness and assess response to intravenous fluid esuscitation. Thorough knowledge of these variables, the physiology behind them and the pitfalls in their use allows the echocardiographer to confidently assess these patients and in combination with clinical judgement manage them appropriately.

Gas powered fluid gun with recoil mitigation

Science.gov (United States)

Grubelich, Mark C; Yonas, Gerold

2013-11-12

A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.

Hazardous fluid leak detector

Science.gov (United States)

Gray, Harold E.; McLaurin, Felder M.; Ortiz, Monico; Huth, William A.

1996-01-01

A device or system for monitoring for the presence of leaks from a hazardous fluid is disclosed which uses two electrodes immersed in deionized water. A gas is passed through an enclosed space in which a hazardous fluid is contained. Any fumes, vapors, etc. escaping from the containment of the hazardous fluid in the enclosed space are entrained in the gas passing through the enclosed space and transported to a closed vessel containing deionized water and two electrodes partially immersed in the deionized water. The electrodes are connected in series with a power source and a signal, whereby when a sufficient number of ions enter the water from the gas being bubbled through it (indicative of a leak), the water will begin to conduct, thereby allowing current to flow through the water from one electrode to the other electrode to complete the circuit and activate the signal.

Failure and nonfailure of fluid filaments in extension

DEFF Research Database (Denmark)

Hassager, Ole; Kolte, Mette Irene; Renardy, Michael

1998-01-01

The phenomenon of ductile failure of Newtonian and viscoelastic fluid filaments without surface tension is studied by a 2D finite element method and by ID non-linear analysis. The viscoelastic fluids are described by single integral constitutive equations. The main conclusions are: (1) Newtonian...... fluid filaments do not exhibit ductile failure without surface tension; (2) some viscoelastic fluids form stable filaments while other fluids exhibit ductile failure as a result of an elastic instability; (3) for large Deborah numbers, the Considere condition may be used to predict the Hencky strain...

Drilling Fluids Using Multiwall Carbon Nanotube (MWCNT

Directory of Open Access Journals (Sweden)

Mostafa Sedaghatzadeh

2012-11-01

Full Text Available Designing drilling fluids for drilling in deep gas reservoirs and geothermal wells is a major challenge. Cooling drilling fluids and preparing stable mud with high thermal conductivity are of great concern. Drilling nanofluids, i.e. a low fraction of carbon nanotube (CNT well dispersed in mud, may enhance the mixture thermal conductivity compared to the base fluids. Thus, they are potentially useful for advanced designing high temperature and high pressure (HTHP drilling fluids. In the present study, the impacts of CNT volume fraction, ball milling time, functionalization, temperature, and dispersion quality (by means of scanning electron microscopy, SEM on the thermal and rheological properties of water-based mud are experimentally investigated. The thermal conductivities of the nano-based drilling fluid are measured with a transient hot wire method. The experimental results show that the thermal conductivity of the water-based drilling fluid is enhanced by 23.2% in the presence of 1 vol% functionalized CNT at room temperature; it increases by 31.8% by raising the mud temperature to 50 °C. Furthermore, significant improvements are seen in the rheological properties—such as yield point, filtration properties, and annular viscosity—of the CNTmodified drilling fluid compared to the base mud, which pushes forward their future development.

Magnelok technology: a complement to magnetorheological fluids

Science.gov (United States)

Carlson, J. David

2004-07-01

Magnetorheological or MR fluids have been successfully used to enable highly effective semi-active control systems in automobile primary suspensions to control unwanted motions in civil engineering structures and to provide force-feedback in steer-by-wire systems. A key to the successful use of MR fluids is an appreciation and understanding of the balance and trade-off between the magnetically controlled on-state force and the ever-present off-state viscous force. In all MR fluid applications, one must deal with the fact that MR fluids never fully decouple or go to zero force in their off-state. Magnelok devices are a magnetically controlled compliment to traditional MR fluid devices that have been developed to enable a true force decoupling in the off-state. Magnelok devices may be embodied as linear or rotary dampers, brakes, lockable struts or position holding devices. They are particularly suitable for lock/un-lock applications. Unlike MR fluid devices they contain no fluid yet they do provide a variable level of friction damping that is controlled by the magnitude of the applied magnetic field. Magnelok devices are low cost as they easily accommodate relatively loose mechanical tolerances and require no seals or accumulator. A variety of controllable Magnelok devices and applications are described.

Directed Fluid Transport with Biomimetic ``Silia'' Arrays

Science.gov (United States)

Shields, A. R.; Evans, B. A.; Carstens, B. L.; Falvo, M. R.; Washburn, S.; Superfine, R.

2008-10-01

We present results on the long-range, directed fluid transport produced by the collective beating of arrays of biomimetic ``silia.'' Silia are arrays of free-standing nanorods roughly the size of biological cilia, which we fabricate from a polymer-magnetic nanoparticle composite material. With external permanent magnets we actuate our silia such that their motion mimics the beating of biological cilia. Biological cilia have evolved to produce microscale fluid transport and are increasingly being recognized as critical components in a wide range of biological systems. However, despite much effort cilia generated fluid flows remain an area of active study. In the last decade, cilia-driven fluid flow in the embryonic node of vertebrates has been implicated as the initial left-right symmetry breaking event in these embryos. With silia we generate directional fluid transport by mimicking the tilted conical beating of these nodal cilia and seek to answer open questions about the nature of particle advection in such a system. By seeding fluorescent microparticles into the fluid we have noted the existence of two distinct flow regimes. The fluid flow is directional and coherent above the tips of the silia, while between the silia tips and floor particle motion is complicated and suggestive of chaotic advection.

Some aspects of fluid-structure coupling

International Nuclear Information System (INIS)

Kulak, R.F.

1982-01-01

The numerical simulation of nonlinear, transient fluid-structure interactions (FSI) is a current area of concern by researchers in various fields, including the field of nuclear reactor safety. This paper primarily discusses the formulation used in an algorithm that couples three-dimensional hydrodynamic and structural domains. The fluid domain is governed by the Navier-Stokes equations, and the structural domain is governed by the equations of nonlinear structural dynamics. Here, both the fluid and structure are discretized using finite elements. The fluid is discretized with eight-noded quasi-Eulerian hexahedrons and the structural components are represented by Lagrangian triangular plate elements. The semi-discretized equations of motion are solved using an explicit temporal integrator. The coupling is accomplished by satisfying interface mechanics. The structure imposes kinematic constraints to the moving fluid boundary, and the fluid in turn provides an external loading on the structure. At each interface node, normals are computed from the nodal basis functions of only the hydrodynamic nodes. By defining the interface normal in this manner, it becomes independent of the type of structural boundary (i.e. shell, plate, continuum etc.) and thus makes this aspect of the coupling independent of the structure type. Results for several problems are presented and these include a comparison between analytical results for a FSI problem and numerical predictions

Stability of fault submitted to fluid injections

Science.gov (United States)

Brantut, N.; Passelegue, F. X.; Mitchell, T. M.

2017-12-01

Elevated pore pressure can lead to slip reactivation on pre-existing fractures and faults when the coulomb failure point is reached. From a static point of view, the reactivation of fault submitted to a background stress (τ0) is a function of the peak strength of the fault, i.e. the quasi-static effective friction coefficient (µeff). However, this theory is valid only when the entire fault is affected by fluid pressure, which is not the case in nature, and during human induced-seismicity. In this study, we present new results about the influence of the injection rate on the stability of faults. Experiments were conducted on a saw-cut sample of westerly granite. The experimental fault was 8 cm length. Injections were conducted through a 2 mm diameter hole reaching the fault surface. Experiments were conducted at four different order magnitudes fluid pressure injection rates (from 1 MPa/minute to 1 GPa/minute), in a fault system submitted to 50 and 100 MPa confining pressure. Our results show that the peak fluid pressure leading to slip depends on injection rate. The faster the injection rate, the larger the peak fluid pressure leading to instability. Wave velocity surveys across the fault highlighted that decreasing the injection-rate leads to an increase of size of the fluid pressure perturbation. Our result demonstrate that the stability of the fault is not only a function of the fluid pressure requires to reach the failure criterion, but is mainly a function of the ratio between the length of the fault affected by fluid pressure and the total fault length. In addition, we show that the slip rate increases with the background effective stress and with the intensity of the fluid pressure pertubation, i.e. with the excess shear stress acting on the part of the fault pertubated by fluid injection. Our results suggest that crustal fault can be reactivated by local high fluid overpressures. These results could explain the "large" magnitude human-induced earthquakes

Handbook of mathematical analysis in mechanics of viscous fluids

CERN Document Server

Novotný, Antonín

2018-01-01

Mathematics has always played a key role for researches in fluid mechanics. The purpose of this handbook is to give an overview of items that are key to handling problems in fluid mechanics. Since the field of fluid mechanics is huge, it is almost impossible to cover many topics. In this handbook, we focus on mathematical analysis on viscous Newtonian fluid. The first part is devoted to mathematical analysis on incompressible fluids while part 2 is devoted to compressible fluids.

4-H NFPA Fluid Power Challenge

OpenAIRE

Bonnett, Erika D

2016-01-01

The 4-H NFPA Fluid Power Challenge partnered Purdue Polytechnic Institute and Indiana 4-H with the National Fluid Power Association and Center for Compact and Efficient Fluid Power to provide teams of Indiana youth in 6-8th grades with opportunity to learn about hydraulics, engineering design, and other STEM skills. This created an opportunity to give youth a learning experience with STEM through hands-on, experiential learning activities. Youth experienced a one day workshop in which they wo...

Fluid Temperature of Aero Hydraulic Systems

Directory of Open Access Journals (Sweden)

I. S. Shumilov

2016-01-01

Full Text Available In modern supersonic aircrafts due to aerodynamic skin heating a temperature of hydraulics environment significantly exceeds that of permissible for fluids used. The same problem exists for subsonic passenger aircrafts, especially for Airbuses, which have hydraulics of high power where convective heat transfer with the environment is insufficient and there is no required temperature control of fluid. The most significant in terms of heat flow is the flow caused by the loss of power to the pump and when designing the hydraulic system (HS it is necessary to pay very serious attention to it. To use a constant capacity pump is absolutely unacceptable, since HS efficiency in this case is extremely low, and the most appropriate are variable-capacity pumps, cut-off pumps, dual-mode pumps. The HS fluid cooling system should provide high reliability, lightweight, simple design, and a specified heat transfer in all flight modes.A system cooling the fluid by the fuel of feeding lines of the aircraft engines is the most effective, and it is widely used in supersonic aircrafts, where power of cooling system is essential. Subsonic aircrafts widely use convective heat exchangers. In thermal design of the aircraft hydraulics, the focus is generally given to the maximum and minimum temperatures of the HS fluid, the choice of the type of heat exchanger (convective or flow-through, the place of its installation. In calculating the operating temperature of a hydraulic system and its cooling systems it is necessary to determine an increase of the working fluid temperature when throttling it. There are three possible formulas to calculate the fluid temperature in throttling, with the error of a calculated temperature drop from 30% to 4%.The article considers the HS stationary and noon-stationary operating conditions and their calculation, defines temperatures of fluid and methods to control its specified temperature. It also discusses various heat exchanger schemes

Linking the tectonic evolution with fluid history in magma-poor rifted margins: tracking mantle- and continental crust-related fluids

Science.gov (United States)

Pinto, V. H. G.; Manatschal, G.; Karpoff, A. M.

2014-12-01

The thinning of the crust and the exhumation of subcontinental mantle is accompanied by a series of extensional detachment faults. Exhumation of mantle and crustal rocks is intimately related to percolation of fluids along detachment faults leading to changes in mineralogy and chemistry of the mantle, crustal and sedimentary rocks. Field observation, analytical methods, refraction/reflection and well-core data, allowed us to investigate the role of fluids in the Iberian margin and former Alpine Tethys distal margins and the Pyrenees rifted system. In the continental crust, fluid-rock interaction leads to saussuritization that produces Si and Ca enriched fluids found in forms of veins along the fault zone. In the zone of exhumed mantle, large amounts of water are absorbed in the first 5-6 km of serpentinized mantle, which has the counter-effect of depleting the mantle of elements (e.g., Si, Ca, Mg, Fe, Mn, Ni and Cr) forming mantle-related fluids. Using Cr-Ni-V and Fe-Mn as tracers, we show that in the distal margin, mantle-related fluids used detachment faults as pathways and interacted with the overlying crust, the sedimentary basin and the seawater, while further inward parts of the margin, continental crust-related fluids enriched in Si and Ca impregnated the fault zone and may have affected the sedimentary basin. The overall observations and results enable us to show when, where and how these interactions occurred during the formation of the rifted margin. In a first stage, continental crust-related fluids dominated the rifted systems. During the second stage, mantle-related fluids affected the overlying syn-tectonic sediments through direct migration along detachment faults at the future distal margin. In a third stage, these fluids reached the seafloor, "polluted" the seawater and were absorbed by post-tectonic sediments. We conclude that a significant amount of serpentinization occurred underneath the thinned continental crust, that the mantle-related fluids

Heat Transfer in Complex Fluids

Energy Technology Data Exchange (ETDEWEB)

Mehrdad Massoudi

2012-01-01

Amongst the most important constitutive relations in Mechanics, when characterizing the behavior of complex materials, one can identify the stress tensor T, the heat flux vector q (related to heat conduction) and the radiant heating (related to the radiation term in the energy equation). Of course, the expression 'complex materials' is not new. In fact, at least since the publication of the paper by Rivlin & Ericksen (1955), who discussed fluids of complexity (Truesdell & Noll, 1992), to the recently published books (Deshpande et al., 2010), the term complex fluids refers in general to fluid-like materials whose response, namely the stress tensor, is 'non-linear' in some fashion. This non-linearity can manifest itself in variety of forms such as memory effects, yield stress, creep or relaxation, normal-stress differences, etc. The emphasis in this chapter, while focusing on the constitutive modeling of complex fluids, is on granular materials (such as coal) and non-linear fluids (such as coal-slurries). One of the main areas of interest in energy related processes, such as power plants, atomization, alternative fuels, etc., is the use of slurries, specifically coal-water or coal-oil slurries, as the primary fuel. Some studies indicate that the viscosity of coal-water mixtures depends not only on the volume fraction of solids, and the mean size and the size distribution of the coal, but also on the shear rate, since the slurry behaves as shear-rate dependent fluid. There are also studies which indicate that preheating the fuel results in better performance, and as a result of such heating, the viscosity changes. Constitutive modeling of these non-linear fluids, commonly referred to as non-Newtonian fluids, has received much attention. Most of the naturally occurring and synthetic fluids are non-linear fluids, for example, polymer melts, suspensions, blood, coal-water slurries, drilling fluids, mud, etc. It should be noted that sometimes these

Free Falling in Stratified Fluids

Science.gov (United States)

Lam, Try; Vincent, Lionel; Kanso, Eva

2017-11-01

Leaves falling in air and discs falling in water are examples of unsteady descents due to complex interaction between gravitational and aerodynamic forces. Understanding these descent modes is relevant to many branches of engineering and science such as estimating the behavior of re-entry space vehicles to studying biomechanics of seed dispersion. For regularly shaped objects falling in homogenous fluids, the motion is relatively well understood. However, less is known about how density stratification of the fluid medium affects the falling behavior. Here, we experimentally investigate the descent of discs in both pure water and in stable linearly stratified fluids for Froude numbers Fr 1 and Reynolds numbers Re between 1000 -2000. We found that stable stratification (1) enhances the radial dispersion of the disc at landing, (2) increases the descent time, (3) decreases the inclination (or nutation) angle, and (4) decreases the fluttering amplitude while falling. We conclude by commenting on how the corresponding information can be used as a predictive model for objects free falling in stratified fluids.

Neural Control Mechanisms and Body Fluid Homeostasis

Science.gov (United States)

Johnson, Alan Kim

1998-01-01

The goal of the proposed research was to study the nature of afferent signals to the brain that reflect the status of body fluid balance and to investigate the central neural mechanisms that process this information for the activation of response systems which restore body fluid homeostasis. That is, in the face of loss of fluids from intracellular or extracellular fluid compartments, animals seek and ingest water and ionic solutions (particularly Na(+) solutions) to restore the intracellular and extracellular spaces. Over recent years, our laboratory has generated a substantial body of information indicating that: (1) a fall in systemic arterial pressure facilitates the ingestion of rehydrating solutions and (2) that the actions of brain amine systems (e.g., norepinephrine; serotonin) are critical for precise correction of fluid losses. Because both acute and chronic dehydration are associated with physiological stresses, such as exercise and sustained exposure to microgravity, the present research will aid in achieving a better understanding of how vital information is handled by the nervous system for maintenance of the body's fluid matrix which is critical for health and well-being.

Selection of fluids for tritium pumping systems

International Nuclear Information System (INIS)

Chastagner, P.

1984-02-01

The degradation characteristics of three types of vacuum pump fluids, polyphenyl ethers, perfluoropolyethers and hydrocarbon oils were reviewed. Fluid selection proved to be a critical factor in the long-term performance of tritium pumping systems and subsequent tritium recovery operations. Thermal degradation and tritium radiolysis of pump fluids produce contaminants which can damage equipment and interfere with tritium recovery operations. General characteristics of these fluids are as follows: polyphenyl ether has outstanding radiation resistance, is very stable under normal diffusion pump conditions, but breaks down in the presence of oxygen at anticipated operating temperatures. Perfluoropolyether fluids are very stable and do not react chemically with most gases. Thermal and mechanical degradation products are inert, but the radiolysis products are very corrosive. Most of the degradation products of hydrogen oils are volatile and the principal radiolysis product is methane. Our studies show that polyphenyl ethers and hydrocarbon oils are the preferred fluids for use in tritium pumping systems. No corrosive materials are formed and most of the degradation products can be removed with suitable filter systems

Spinodal decomposition in fluid mixtures

International Nuclear Information System (INIS)

Kawasaki, Kyozi; Koga, Tsuyoshi

1993-01-01

We study the late stage dynamics of spinodal decomposition in binary fluids by the computer simulation of the time-dependent Ginzburg-Landau equation. We obtain a temporary linear growth law of the characteristic length of domains in the late stage. This growth law has been observed in many real experiments of binary fluids and indicates that the domain growth proceeds by the flow caused by the surface tension of interfaces. We also find that the dynamical scaling law is satisfied in this hydrodynamic domain growth region. By comparing the scaling functions for fluids with that for the case without hydrodynamic effects, we find that the scaling functions for the two systems are different. (author)

Computational fluid dynamics incompressible turbulent flows

CERN Document Server

Kajishima, Takeo

2017-01-01

This textbook presents numerical solution techniques for incompressible turbulent flows that occur in a variety of scientific and engineering settings including aerodynamics of ground-based vehicles and low-speed aircraft, fluid flows in energy systems, atmospheric flows, and biological flows. This book encompasses fluid mechanics, partial differential equations, numerical methods, and turbulence models, and emphasizes the foundation on how the governing partial differential equations for incompressible fluid flow can be solved numerically in an accurate and efficient manner. Extensive discussions on incompressible flow solvers and turbulence modeling are also offered. This text is an ideal instructional resource and reference for students, research scientists, and professional engineers interested in analyzing fluid flows using numerical simulations for fundamental research and industrial applications. • Introduces CFD techniques for incompressible flow and turbulence with a comprehensive approach; • Enr...

Tunable 'optical activity' in electrorheological fluids

International Nuclear Information System (INIS)

Zhao, Q.; Zhao, X.P.

2005-01-01

The 'optical activity' of adjustable periodic structure material (SiO 2 and pentaerythrital electrorheological (ER) fluids) is firstly investigated using two kinds of setup. It is found that the rotation angles can be tuned by the external electric field and weight concentrations, and the sign of the rotation angle is negative, so, the used ER fluids are defined as the left-handed optically active substances under the application of electric field. The laser diffraction patterns are also observed in the ER fluids, which indicates the formation of alignment. It is thought that the symmetry breaking of structure induced by applied electric field is the origin of the 'optical activity' in the ER fluids. The electrically tunable 'optical activity' will find innovative applications in displays, optical devices and other fields

Multiple stable isotope fronts during non-isothermal fluid flow

Science.gov (United States)

Fekete, Szandra; Weis, Philipp; Scott, Samuel; Driesner, Thomas

2018-02-01

Stable isotope signatures of oxygen, hydrogen and other elements in minerals from hydrothermal veins and metasomatized host rocks are widely used to investigate fluid sources and paths. Previous theoretical studies mostly focused on analyzing stable isotope fronts developing during single-phase, isothermal fluid flow. In this study, numerical simulations were performed to assess how temperature changes, transport phenomena, kinetic vs. equilibrium isotope exchange, and isotopic source signals determine mineral oxygen isotopic compositions during fluid-rock interaction. The simulations focus on one-dimensional scenarios, with non-isothermal single- and two-phase fluid flow, and include the effects of quartz precipitation and dissolution. If isotope exchange between fluid and mineral is fast, a previously unrecognized, significant enrichment in heavy oxygen isotopes of fluids and minerals occurs at the thermal front. The maximum enrichment depends on the initial isotopic composition of fluid and mineral, the fluid-rock ratio and the maximum change in temperature, but is independent of the isotopic composition of the incoming fluid. This thermally induced isotope front propagates faster than the signal related to the initial isotopic composition of the incoming fluid, which forms a trailing front behind the zone of transient heavy oxygen isotope enrichment. Temperature-dependent kinetic rates of isotope exchange between fluid and rock strongly influence the degree of enrichment at the thermal front. In systems where initial isotope values of fluids and rocks are far from equilibrium and isotope fractionation is controlled by kinetics, the temperature increase accelerates the approach of the fluid to equilibrium conditions with the host rock. Consequently, the increase at the thermal front can be less dominant and can even generate fluid values below the initial isotopic composition of the input fluid. As kinetics limit the degree of isotope exchange, a third front may

Characteristics of laminar MHD fluid hammer in pipe

International Nuclear Information System (INIS)

Huang, Z.Y.; Liu, Y.J.

2016-01-01

As gradually wide applications of MHD fluid, transportation as well as control with pumps and valves is unavoidable, which induces MHD fluid hammer. The paper attempts to combine MHD effect and fluid hammer effect and to investigate the characteristics of laminar MHD fluid hammer. A non-dimensional fluid hammer model, based on Navier–Stocks equations, coupling with Lorentz force is numerically solved in a reservoir–pipe–valve system with uniform external magnetic field. The MHD effect is represented by the interaction number which associates with the conductivity of the MHD fluid as well as the external magnetic field and can be interpreted as the ratio of Lorentz force to Joukowsky force. The transient numerical results of pressure head, average velocity, wall shear stress, velocity profiles and shear stress profiles are provided. The additional MHD effect hinders fluid motion, weakens wave front and homogenizes velocity profiles, contributing to obvious attenuation of oscillation, strengthened line packing and weakened Richardson annular effect. Studying the characteristics of MHD laminar fluid hammer theoretically supplements the gap of knowledge of rapid-transient MHD flow and technically provides beneficial information for MHD pipeline system designers to better devise MHD systems. - Highlights: • Characteristics of laminar MHD fluid hammer are discussed by simulation. • MHD effect has significant influence on attenuation of wave. • MHD effect strengthens line packing. • MHD effect inhibits Richardson annular effect.

Hydrodynamic response of viscous fluids under seismic excitation

International Nuclear Information System (INIS)

Ma, D.C.

1993-01-01

Hydrodynamic response of liquid-tank systems, such as reactor vessels, spent-fuel pools and liquid storage tanks have been studied extensively in the last decade (Chang et al. 1988; Ma et al. 1991). However, most of the studies are conducted with the assumption of an inviscid fluid. In recent years, the hydrodynamic response of viscous fluids has received increasing attention in high level waste storage tanks containing viscous waste material. This paper presents a numerical study on the hydrodynamic response of viscous fluids in a large 2-D fluid-tank system under seismic excitation. Hydrodynamic responses (i.e. sloshing wave height, fluid pressures, shear stress, etc.) are calculated for a fluid with various viscosities. Four fluid viscosities are considered. They are 1 cp, 120 cp, 1,000 cp and 12,000 cp (1 cp = 1.45 x 10 -7 lb-sec/in 2 ). Note that the liquid sodium of the Liquid-Metal Reactor (LMR) reactor has a viscosity of 1.38 x 10 -5 lb-sec/in 2 (about 95 cp) at an operational temperature of 900 degree F. Section 2 describes the pertinent features of the mathematical model. In Section 3, the fundamental sloshing phenomena of viscous fluid are examined. Sloshing wave height and shear stress for fluid with different viscosities are compared. The conclusions are given in Section 4

Local invariants in non-ideal flows of neutral fluids and two-fluid plasmas

Science.gov (United States)

Zhu, Jian-Zhou

2018-03-01

The main objective is the locally invariant geometric object of any (magneto-)fluid dynamics with forcing and damping (nonideal), while more attention is paid to the untouched dynamical properties of two-fluid fashion. Specifically, local structures, beyond the well-known "frozen-in" to the barotropic flows of the generalized vorticities, of the two-fluid model of plasma flows are presented. More general non-barotropic situations are also considered. A modified Euler equation [T. Tao, "Finite time blowup for Lagrangian modifications of the three-dimensional Euler equation," Ann. PDE 2, 9 (2016)] is also accordingly analyzed and remarked from the angle of view of the two-fluid model, with emphasis on the local structures. The local constraints of high-order differential forms such as helicity, among others, find simple formulation for possible practices in modeling the dynamics. Thus, the Cauchy invariants equation [N. Besse and U. Frisch, "Geometric formulation of the Cauchy invariants for incompressible Euler flow in flat and curved spaces," J. Fluid Mech. 825, 412 (2017)] may be enabled to find applications in non-ideal flows. Some formal examples are offered to demonstrate the calculations, and particularly interestingly the two-dimensional-three-component (2D3C) or the 2D passive scalar problem presents that a locally invariant Θ = 2θζ, with θ and ζ being, respectively, the scalar value of the "vertical velocity" (or the passive scalar) and the "vertical vorticity," may be used as if it were the spatial density of the globally invariant helicity, providing a Lagrangian prescription to control the latter in some situations of studying its physical effects in rapidly rotating flows (ubiquitous in atmosphere of astrophysical objects) with marked 2D3C vortical modes or in purely 2D passive scalars.

Clusters in simple fluids

International Nuclear Information System (INIS)

Sator, N.

2003-01-01

This article concerns the correspondence between thermodynamics and the morphology of simple fluids in terms of clusters. Definitions of clusters providing a geometric interpretation of the liquid-gas phase transition are reviewed with an eye to establishing their physical relevance. The author emphasizes their main features and basic hypotheses, and shows how these definitions lead to a recent approach based on self-bound clusters. Although theoretical, this tutorial review is also addressed to readers interested in experimental aspects of clustering in simple fluids

Fluid flow control system

International Nuclear Information System (INIS)

Rion, Jacky.

1982-01-01

Fluid flow control system featuring a series of grids placed perpendicular to the fluid flow direction, characterized by the fact that it is formed of a stack of identical and continuous grids, each of which consists of identical meshes forming a flat lattice. The said meshes are offset from one grid to the next. This system applies in particular to flow control of the coolant flowing at the foot of an assembly of a liquid metal cooled nuclear reactor [fr

A lattice Boltzmann investigation of steady-state fluid distribution, capillary pressure and relative permeability of a porous medium: Effects of fluid and geometrical properties

Science.gov (United States)

Li, Zi; Galindo-Torres, Sergio; Yan, Guanxi; Scheuermann, Alexander; Li, Ling

2018-06-01

Simulations of simultaneous steady-state two-phase flow in the capillary force-dominated regime were conducted using the state-of-the-art Shan-Chen multi-component lattice Boltzmann model (SCMC-LBM) based on two-dimensional porous media. We focused on analyzing the fluid distribution (i.e., WP fluid-solid, NP fluid-solid and fluid-fluid interfacial areas) as well as the capillary pressure versus saturation curve which was affected by fluid and geometrical properties (i.e., wettability, adhesive strength, pore size distribution and specific surface area). How these properties influenced the relative permeability versus saturation relation through apparent effective permeability and threshold pressure gradient was also explored. The SCMC-LBM simulations showed that, a thin WP fluid film formed around the solid surface due to the adhesive fluid-solid interaction, resulting in discrete WP fluid distributions and reduction of the WP fluid mobility. Also, the adhesive interaction provided another source of capillary pressure in addition to capillary force, which, however, did not affect the mobility of the NP fluid. The film fluid effect could be enhanced by large adhesive strength and fine pores in heterogeneous porous media. In the steady-state infiltration, not only the NP fluid but also the WP fluid were subjected to the capillary resistance. The capillary pressure effect could be alleviated by decreased wettability, large average pore radius and improved fluid connectivity in heterogeneous porous media. The present work based on the SCMC-LBM investigations elucidated the role of film fluid as well as capillary pressure in the two-phase flow system. The findings have implications for ways to improve the macroscopic flow equation based on balance of force for the steady-state infiltration.

Variational description of multifluid hydrodynamics: Uncharged fluids

Science.gov (United States)

Prix, Reinhard

2004-02-01

We present a formalism for Newtonian multifluid hydrodynamics derived from an unconstrained variational principle. This approach provides a natural way of obtaining the general equations of motion for a wide range of hydrodynamic systems containing an arbitrary number of interacting fluids and superfluids. In addition to spatial variations we use “time shifts” in the variational principle, which allows us to describe dissipative processes with entropy creation, such as chemical reactions, friction or the effects of external non-conservative forces. The resulting framework incorporates the generalization of the entrainment effect originally discussed in the case of the mixture of two superfluids by Andreev and Bashkin. In addition to the conservation of energy and momentum, we derive the generalized conservation laws of vorticity and helicity, and the special case of Ertel’s theorem for the single perfect fluid. We explicitly discuss the application of this framework to thermally conducting fluids, superfluids, and superfluid neutron star matter. The equations governing thermally conducting fluids are found to be more general than the standard description, as the effect of entrainment usually seems to be overlooked in this context. In the case of superfluid 4He we recover the Landau-Khalatnikov equations of the two-fluid model via a translation to the “orthodox” framework of superfluidity, which is based on a rather awkward choice of variables. Our two-fluid model for superfluid neutron star matter allows for dissipation via mutual friction and also “transfusion” via β reactions between the neutron fluid and the proton-electron fluid.

Fluid-chemical evidence for one billion years of fluid flow through Mesoproterozoic deep-water carbonate mounds (Nanisivik zinc district, Nunavut)

Science.gov (United States)

Hahn, K. E.; Turner, E. C.; Kontak, D. J.; Fayek, M.

2018-02-01

Ancient carbonate rocks commonly contain numerous post-depositional phases (carbonate minerals; quartz) recording successive diagenetic events that can be deciphered and tied to known or inferred geological events using a multi-pronged in situ analytical protocol. The framework voids of large, deep-water microbial carbonate seep-mounds in Arctic Canada (Mesoproterozoic Ikpiarjuk Formation) contain multiple generations of synsedimentary and late cement. An in situ analytical study of the post-seafloor cements used optical and cathodoluminescence petrography, SEM-EDS analysis, fluid inclusion (FI) microthermometry and evaporate mound analysis, LA-ICP-MS analysis, and SIMS δ18O to decipher the mounds' long-term diagenetic history. The six void-filling late cements include, in paragenetic order: inclusion-rich euhedral dolomite (ED), finely crystalline clear dolomite (FCD), hematite-bearing dolomite (HD), coarsely crystalline clear dolomite (CCD), quartz (Q), replacive calcite (RC) and late calcite (LC). Based on the combined analytical results, the following fluid-flow history is defined: (1) ED precipitation by autocementation during shallow burial (fluid 1; Mesoproterozoic); (2) progressive mixing of Ca-rich hydrothermal fluid with the connate fluid, resulting in precipitation of FCD followed by HD (fluid 2; also Mesoproterozoic); (3) precipitation of hydrothermal dolomite (CCD) from high-Ca and K-rich fluids (fluid 3; possibly Mesoproterozoic, but timing unclear); (4) hydrothermal Q precipitation (fluid 4; timing unclear), and (5) RC and LC precipitation from a meteoric-derived water (fluid 5) in or since the Mesozoic. Fluids associated with FCD, HD, and CCD may have been mobilised during deposition of the upper Bylot Supergroup; this time interval was the most tectonically active episode in the region's Mesoproterozoic to Recent history. The entire history of intermittent fluid migration and cement precipitation recorded in seemingly unimportant void

Intravenous fluid prescription practices among pediatric residents in Korea

Directory of Open Access Journals (Sweden)

Jiwon M. Lee

2013-07-01

Full Text Available Purpose: Recent studies have established the association between hypotonic fluids administration and hospital-acquired hyponatremia in children, and have contended that hypotonic fluids be removed from routine practice. To assess current intravenous fluid prescription practices among Korean pediatric residents and to call for updated clinical-practice education Methods: A survey-based analysis was carried out. Pediatric residents at six university hospitals in Korea completed a survey consisting of four questions. Each question supposed a unique scenario in which the respondents were to prescribe either a hypotonic or an isotonic fluid for the patient. Results: Ninety-one responses were collected and analyzed. In three of the four scenarios, a significant majority prescribed the hypotonic fluids (98.9%, 85.7%, and 69.2%, respectively. Notably, 69.2% of the respondents selected the hypotonic fluids for postoperative management. Almost all (96.7% selected the isotonic fluids for hydration therapy. Conclusion: In the given scenarios, the majority of Korean pediatric residents would prescribe a hypotonic fluid, except for initial hydration. The current state of pediatric fluid management, notably, heightens the risk of hospital-acquired hyponatremia. Updated clinical practice education on intravenous fluid prescription, therefore, is urgently required.

Mechanistic Fluid Transport Model to Estimate Gastrointestinal Fluid Volume and Its Dynamic Change Over Time.

Science.gov (United States)

Yu, Alex; Jackson, Trachette; Tsume, Yasuhiro; Koenigsknecht, Mark; Wysocki, Jeffrey; Marciani, Luca; Amidon, Gordon L; Frances, Ann; Baker, Jason R; Hasler, William; Wen, Bo; Pai, Amit; Sun, Duxin

2017-11-01

Gastrointestinal (GI) fluid volume and its dynamic change are integral to study drug disintegration, dissolution, transit, and absorption. However, key questions regarding the local volume and its absorption, secretion, and transit remain unanswered. The dynamic fluid compartment absorption and transit (DFCAT) model is proposed to estimate in vivo GI volume and GI fluid transport based on magnetic resonance imaging (MRI) quantified fluid volume. The model was validated using GI local concentration of phenol red in human GI tract, which was directly measured by human GI intubation study after oral dosing of non-absorbable phenol red. The measured local GI concentration of phenol red ranged from 0.05 to 168 μg/mL (stomach), to 563 μg/mL (duodenum), to 202 μg/mL (proximal jejunum), and to 478 μg/mL (distal jejunum). The DFCAT model characterized observed MRI fluid volume and its dynamic changes from 275 to 46.5 mL in stomach (from 0 to 30 min) with mucus layer volume of 40 mL. The volumes of the 30 small intestine compartments were characterized by a max of 14.98 mL to a min of 0.26 mL (0-120 min) and a mucus layer volume of 5 mL per compartment. Regional fluid volumes over 0 to 120 min ranged from 5.6 to 20.38 mL in the proximal small intestine, 36.4 to 44.08 mL in distal small intestine, and from 42 to 64.46 mL in total small intestine. The DFCAT model can be applied to predict drug dissolution and absorption in the human GI tract with future improvements.

On the existence of weak solution to the coupled fluid-structure interaction problem for non-Newtonian shear-dependent fluid

Czech Academy of Sciences Publication Activity Database

Hundertmark-Zaušková, A.; Lukáčová-Medviďová, M.; Nečasová, Šárka

2016-01-01

Roč. 68, č. 1 (2016), s. 193-243 ISSN 0025-5645 R&D Projects: GA ČR(CZ) GAP201/11/1304 Institutional support: RVO:67985840 Keywords : non-Newtonian fluids * fluid-structure interaction * shear-thinning fluids Subject RIV: BA - General Mathematics Impact factor: 0.592, year: 2016 http://projecteuclid.org/euclid.jmsj/1453731541

On perfect fluids and black holes in static equilibrium

International Nuclear Information System (INIS)

Carrasco, Alberto; Mars, Marc; Simon, Walter

2007-01-01

Proofs of spherical symmetry of static black holes and of spherical symmetry of static perfect fluids normally require, a priori, 'black holes only' or 'fluid only'. In a recent paper Shiromizu, Yamada and Yoshino admit a priori (and exclude) coexistence of fluids and holes. This work assumes connectedness of the fluid region and the same assumptions on the equation of state as earlier papers on the 'fluid only' case, and requires in addition an upper bound for the fluid mass in terms of the black holes masses. We discuss this paper. As a new result we show that there cannot exist static fluid shells (i.e. fluid regions of the topology of an annulus) even if one a priori admits, inside and outside the shell, any arrangement of black holes or additional matter which satisfies the energy condition

Geothermal energy production with supercritical fluids

Science.gov (United States)

Brown, Donald W.

2003-12-30

There has been invented a method for producing geothermal energy using supercritical fluids for creation of the underground reservoir, production of the geothermal energy, and for heat transport. Underground reservoirs are created by pumping a supercritical fluid such as carbon dioxide into a formation to fracture the rock. Once the reservoir is formed, the same supercritical fluid is allowed to heat up and expand, then is pumped out of the reservoir to transfer the heat to a surface power generating plant or other application.

Hydromagnetic stability of rotating stratified compressible fluid flows

Energy Technology Data Exchange (ETDEWEB)

Srinivasan, V; Kandaswamy, P [Dept. of Mathematics, Bharathiar University, Coimbatore, Tamil Nadu, India; Debnath, L [Dept. of Mathematics, University of Central Florida, Orlando, USA

1984-09-01

The hydromagnetic stability of a radially stratified compressible fluid rotating between two coaxial cylinders is investigated. The stability with respect to axisymmetric disturbances is examined. The fluid system is found to be thoroughly stable to axisymmetric disturbances provided the fluid rotates very rapidly. The system is shown to be unstable to non-axisymmetric disturbances, and the slow amplifying hydromagnetic wave modes propagate against the basic rotation. The lower and upper bounds of the azimuthal phase speeds of the amplifying waves are determined. A quadrant theorem on the slow waves characteristic of a rapidly rotating fluid is derived. Special attention is given to the effects of compressibility of the fluid. Some results concerning the stability of an incompressible fluid system are obtained as special cases of the present analysis.

Interfacial instabilities in vibrated fluids

Science.gov (United States)

Porter, Jeff; Laverón-Simavilla, Ana; Tinao Perez-Miravete, Ignacio; Fernandez Fraile, Jose Javier

2016-07-01

Vibrations induce a range of different interfacial phenomena in fluid systems depending on the frequency and orientation of the forcing. With gravity, (large) interfaces are approximately flat and there is a qualitative difference between vertical and horizontal forcing. Sufficient vertical forcing produces subharmonic standing waves (Faraday waves) that extend over the whole interface. Horizontal forcing can excite both localized and extended interfacial phenomena. The vibrating solid boundaries act as wavemakers to excite traveling waves (or sloshing modes at low frequencies) but they also drive evanescent bulk modes whose oscillatory pressure gradient can parametrically excite subharmonic surface waves like cross-waves. Depending on the magnitude of the damping and the aspect ratio of the container, these locally generated surfaces waves may interact in the interior resulting in temporal modulation and other complex dynamics. In the case where the interface separates two fluids of different density in, for example, a rectangular container, the mass transfer due to vertical motion near the endwalls requires a counterflow in the interior region that can lead to a Kelvin-Helmholtz type instability and a ``frozen wave" pattern. In microgravity, the dominance of surface forces favors non-flat equilibrium configurations and the distinction between vertical and horizontal applied forcing can be lost. Hysteresis and multiplicity of solutions are more common, especially in non-wetting systems where disconnected (partial) volumes of fluid can be established. Furthermore, the vibrational field contributes a dynamic pressure term that competes with surface tension to select the (time averaged) shape of the surface. These new (quasi-static) surface configurations, known as vibroequilibria, can differ substantially from the hydrostatic state. There is a tendency for the interface to orient perpendicular to the vibrational axis and, in some cases, a bulge or cavity is induced

The Correlation between Serum and Peritoneal Fluid CA125 The Correlation between Serum and Peritoneal Fluid CA125

Directory of Open Access Journals (Sweden)

Saghar Salehpour

2009-01-01

Full Text Available Background: Despite a high prevalence of endometriosis, there still exist many challenges indiagnosing the disease. This study aims to evaluate non-invasive and practical diagnostic methodsby measuring serum and peritoneal fluid CA 125 levels in patients with endometriosis. A secondaryaim is to determine the correlation between these markers with the stage of disease as well as therelationship of the two markers with each other.Materials and Methods: This is a cross-sectional study of 60 women who underwent laparoscopyfor benign conditions. Based on laparoscopic findings and biopsy results, patients were divided to twogroups; one group included patients with pelvic endometriosis (35 patients and the second enrolledpatients free from endometriosis (25 patients. Serum and peritoneal fluid specimens were provided at thetime of laparoscopy and CA125 levels were then assessed by electrochemiluminescence immunoassay.Results: Mean serum and peritoneal fluid CA125 levels were significantly higher in women withendometriosis as compared to the control group (26.42 ± 24.34 IU/ml versus 12.64 ± 6.87 IU/mlin serum and 2203.54 + 993.19 IU/ml versus 1583.42 ± 912.51 IU/ml in peritoneal fluid, p<0.05.CA 125 levels also varied proportionally with the stage of endometriosis; but showed a significantdifference only in higher stages of the disease, both in serum and peritoneal fluid. We calculatedthe cut-off value suggesting a diagnosis of pelvic endometriosis as 14.70 IU/ml for serum and1286.5 IU/ml for peritoneal fluid CA125. A linear correlation between CA 125 levels in serum andperitoneal fluid in patients with pelvic endometriosis has also been observed.Conclusion: Serum and peritoneal fluid CA 125 levels are simple and non-surgical tools fordiagnosing and staging pelvic endometriosis. These markers are of greater diagnostic value inhigher stages of the disease.

Big bang nucleosynthesis with a stiff fluid

International Nuclear Information System (INIS)

Dutta, Sourish; Scherrer, Robert J.

2010-01-01

Models that lead to a cosmological stiff fluid component, with a density ρ S that scales as a -6 , where a is the scale factor, have been proposed recently in a variety of contexts. We calculate numerically the effect of such a stiff fluid on the primordial element abundances. Because the stiff fluid energy density decreases with the scale factor more rapidly than radiation, it produces a relatively larger change in the primordial helium-4 abundance than in the other element abundances, relative to the changes produced by an additional radiation component. We show that the helium-4 abundance varies linearly with the density of the stiff fluid at a fixed fiducial temperature. Taking ρ S10 and ρ R10 to be the stiff fluid energy density and the standard density in relativistic particles, respectively, at T=10 MeV, we find that the change in the primordial helium abundance is well-fit by ΔY p =0.00024(ρ S10 /ρ R10 ). The changes in the helium-4 abundance produced by additional radiation or by a stiff fluid are identical when these two components have equal density at a 'pivot temperature', T * , where we find T * =0.55 MeV. Current estimates of the primordial 4 He abundance give the constraint on a stiff fluid energy density of ρ S10 /ρ R10 <30.

Fluid and Electrolyte Disturbances in Critically Ill Patients

OpenAIRE

Lee, Jay Wook

2010-01-01

Disturbances in fluid and electrolytes are among the most common clinical problems encountered in the intensive care unit (ICU). Recent studies have reported that fluid and electrolyte imbalances are associated with increased morbidity and mortality among critically ill patients. To provide optimal care, health care providers should be familiar with the principles and practice of fluid and electrolyte physiology and pathophysiology. Fluid resuscitation should be aimed at restoration of normal...

Flask fluid flow simulation using CFD

International Nuclear Information System (INIS)

Swindlehurst, W.E.; Livesey, E.; Worthington, D.

1989-01-01

BNFL and its subsidiary Company, PNTL, design and operate waterfilled LWR fuel transport flasks for the international transport of irradiated fuel. Although some 150 flasks are currently in operation, new flask designs are being developed. As part of the supporting R and D program, Computational Fluid Dynamics (CFD) codes are being investigated as a means of predicting fluid movements and temperatures within the complex internal geometry of flasks. The ability to simulate fluid flow is particularly important when convection heat transfer is significant. Although obviously relevant to water filled flasks, the technique is applicable to dry flask thermal assessments (where experience shows that convection heat transfer is often underestimated). Computational Fluid Dynamics has emerged in recent years as an important technique in engineering design and safety assessments. Cheaper computing and the development of general CFD codes allows complex engineering structures to be analyzed. However, because of this complexity, it is essential that the application and associated modeling assumptions are critically reviewed. To assess the ability of a CFD code to model flask internals, the code PHOENICS has been used to model the fluid movements in a BNFL Excellox-type flask and the results compared with test data

Fluid structure interaction in piping systems

Energy Technology Data Exchange (ETDEWEB)

Svingen, Bjoernar

1996-12-31

The Dr. ing. thesis relates to an analysis of fluid structure interaction in piping systems in the frequency domain. The governing equations are the water hammer equations for the liquid, and the beam-equations for the structure. The fluid and structural equations are coupled through axial stresses and fluid continuity relations controlled by the contraction factor (Poisson coupling), and continuity and force relations at the boundaries (junction coupling). A computer program has been developed using the finite element method as a discretization technique both for the fluid and for the structure. This is made for permitting analyses of large systems including branches and loops, as well as including hydraulic piping components, and experiments are executed. Excitations are made in a frequency range from zero Hz and up to at least one thousand Hz. Frequency dependent friction is modelled as stiffness proportional Rayleigh damping both for the fluid and for the structure. With respect to the water hammer equations, stiffness proportional damping is seen as an artificial (bulk) viscosity term. A physical interpretation of this term in relation to transient/oscillating hydraulic pipe-friction is given. 77 refs., 72 figs., 4 tabs.

Dynamic characteristics of Non Newtonian fluid Squeeze film damper

Science.gov (United States)

Palaksha, C. P.; Shivaprakash, S.; Jagadish, H. P.

2016-09-01

The fluids which do not follow linear relationship between rate of strain and shear stress are termed as non-Newtonian fluid. The non-Newtonian fluids are usually categorized as those in which shear stress depends on the rates of shear only, fluids for which relation between shear stress and rate of shear depends on time and the visco inelastic fluids which possess both elastic and viscous properties. It is quite difficult to provide a single constitutive relation that can be used to define a non-Newtonian fluid due to a great diversity found in its physical structure. Non-Newtonian fluids can present a complex rheological behaviour involving shear-thinning, viscoelastic or thixotropic effects. The rheological characterization of complex fluids is an important issue in many areas. The paper analyses the damping and stiffness characteristics of non-Newtonian fluids (waxy crude oil) used in squeeze film dampers using the available literature for viscosity characterization. Damping and stiffness characteristic will be evaluated as a function of shear strain rate, temperature and percentage wax concentration etc.

Intravenous fluid prescription practices among pediatric residents in Korea.

Science.gov (United States)

Lee, Jiwon M; Jung, Younghwa; Lee, Se Eun; Lee, Jun Ho; Kim, Kee Hyuck; Koo, Ja Wook; Park, Young Seo; Cheong, Hae Il; Ha, Il-Soo; Choi, Yong; Kang, Hee Gyung

2013-07-01

Recent studies have established the association between hypotonic fluids administration and hospital-acquired hyponatremia in children. The present paper investigated the pattern of current practice in intravenous fluid prescription among Korean pediatric residents, to underscore the need for updated education. A survey-based analysis was carried out. Pediatric residents at six university hospitals in Korea completed a survey consisting of four questions. Each question proposed a unique scenario in which the respondents had to prescribe either a hypotonic or an isotonic fluid for the patient. Ninety-one responses were collected and analyzed. In three of the four scenarios, a significant majority prescribed the hypotonic fluids (98.9%, 85.7%, and 69.2%, respectively). Notably, 69.2% of the respondents selected the hypotonic fluids for postoperative management. Almost all (96.7%) selected the isotonic fluids for hydration therapy. In the given scenarios, the majority of Korean pediatric residents would prescribe a hypotonic fluid, except for initial hydration. The current state of pediatric fluid management, notably, heightens the risk of hospital-acquired hyponatremia. Updated clinical practice education on intravenous fluid prescription, therefore, is urgently required.

A new method used to evaluate organic working fluids

International Nuclear Information System (INIS)

Zhang, Xinxin; He, Maogang; Wang, Jingfu

2014-01-01

In this paper, we propose a method named “Weight Classification-Hasse Dominance” to evaluate organic working fluids. This new method combines the advantages of both the method of weight determination and the Hasse Diagram Technique (HDT). It can be used to evaluate the thermodynamic performance, environmental protection indicator, and safety requirement of organic working fluid simultaneously. This evaluation method can offer good reference for working fluid selection. Using this method, the organic working fluids which have been phased out and will be phased out by the Montreal Protocol including CFCs (chlorofluorocarbons), HCFCs (hydrochlorofluorocarbons), and HFCs (hydrofluorocarbons) were evaluated. Moreover, HCs (hydrocarbons) can be considered as a completely different kind of organic working fluid from CFCs, HCFCs, and HFCs according to the comparison based on this new evaluation method. - Highlights: • We propose a new method used to evaluate organic working fluids. • This evaluation method can offer good reference for working fluid selection. • CFC, HCFC, and HFC working fluids were evaluated using this evaluation method. • HC can be considered as a totally different working fluid from CFC, HCFC, and HFC

Topology optimization of fluid mechanics problems

DEFF Research Database (Denmark)

Gersborg-Hansen, Allan

While topology optimization for solid continuum structures have been studied for about 20 years and for the special case of trusses for many more years, topology optimization of fluid mechanics problems is more recent. Borrvall and Petersson [1] is the seminal reference for topology optimization......D Navier-Stokes equation as well as an example with convection dominated transport in 2D Stokes flow. Using Stokes flow limits the range of applications; nonetheless, the present work gives a proof-of-concept for the application of the method within fluid mechanics problems and it remains...... processing tool. Prior to design manufacturing this allows the engineer to quantify the performance of the computed topology design using standard, credible analysis tools with a body-fitted mesh. [1] Borrvall and Petersson (2003) "Topology optimization of fluids in Stokes flow", Int. J. Num. Meth. Fluids...

Computational and Experimental Investigations of the Molecular Scale Structure and Dynamics of Gologically Important Fluids and Mineral-Fluid Interfaces

Energy Technology Data Exchange (ETDEWEB)

Bowers, Geoffrey [Alfred Univ., NY (United States)

2017-04-05

United States Department of Energy grant DE-FG02-10ER16128, “Computational and Spectroscopic Investigations of the Molecular Scale Structure and Dynamics of Geologically Important Fluids and Mineral-Fluid Interfaces” (Geoffrey M. Bowers, P.I.) focused on developing a molecular-scale understanding of processes that occur in fluids and at solid-fluid interfaces using the combination of spectroscopic, microscopic, and diffraction studies with molecular dynamics computer modeling. The work is intimately tied to the twin proposal at Michigan State University (DOE DE-FG02-08ER15929; same title: R. James Kirkpatrick, P.I. and A. Ozgur Yazaydin, co-P.I.).

On perfect fluids and black holes in static equilibrium

Energy Technology Data Exchange (ETDEWEB)

Carrasco, Alberto; Mars, Marc; Simon, Walter [Facultad de Ciencias, Universidad de Salamanca, Plaza de la Merced s/n, 37008 Salamanca (Spain)

2007-05-15

Proofs of spherical symmetry of static black holes and of spherical symmetry of static perfect fluids normally require, a priori, 'black holes only' or 'fluid only'. In a recent paper Shiromizu, Yamada and Yoshino admit a priori (and exclude) coexistence of fluids and holes. This work assumes connectedness of the fluid region and the same assumptions on the equation of state as earlier papers on the 'fluid only' case, and requires in addition an upper bound for the fluid mass in terms of the black holes masses. We discuss this paper. As a new result we show that there cannot exist static fluid shells (i.e. fluid regions of the topology of an annulus) even if one a priori admits, inside and outside the shell, any arrangement of black holes or additional matter which satisfies the energy condition.

Dynamic Characteristics of Magneto-Fluid Supports

Directory of Open Access Journals (Sweden)

V. A. Chernobai

2008-01-01

Full Text Available The paper considers a vibro-protective magneto-fluid support that uses elastic properties of magnetic fluid with a free surface in magnetic field.The paper has experimentally revealed that the analyzed structure is characterized by better noise absorbing characteristics.The conducted experiments have made it possible to conclude that there is a possibility to use vibro-protective magneto-fluid supports within the frequency range from 0 to 300 Hz, amplitudes up to 2 mm and unit load up to 2,5 · 10 4 Н/м².

Magnetization of High Density Hadronic Fluid

DEFF Research Database (Denmark)

Bohr, Henrik; Providencia, Constanca; da Providencia, João

2012-01-01

In the present paper the magnetization of a high density relativistic fluid of elementary particles is studied. At very high densities, such as may be found in the interior of a neutron star, when the external magnetic field is gradually increased, the energy of the normal phase of the fluid...... in the particle fluid. For nuclear densities above 2 to 3 rho(0), where rho(0) is the equilibrium nuclear density, the resulting magnetic field turns out to be rather huge, of the order of 10(17) Gauss....

Fluid simulation for computer graphics

CERN Document Server

Bridson, Robert

2008-01-01

Animating fluids like water, smoke, and fire using physics-based simulation is increasingly important in visual effects, in particular in movies, like The Day After Tomorrow, and in computer games. This book provides a practical introduction to fluid simulation for graphics. The focus is on animating fully three-dimensional incompressible flow, from understanding the math and the algorithms to the actual implementation.

Endoscopic Management of Pancreatic Fluid Collections in Children.

Science.gov (United States)

Nabi, Zaheer; Talukdar, Rupjyoti; Reddy, D Nageshwar

2017-07-15

The incidence of acute pancreatitis in children has increased over the last few decades. The development of pancreatic fluid collection is not uncommon after severe acute pancreatitis, although its natural course in children and adolescents is poorly understood. Asymptomatic fluid collections can be safely observed without any intervention. However, the presence of clinically significant symptoms warrants the drainage of these fluid collections. Endoscopic management of pancreatic fluid collection is safe and effective in adults. The use of endoscopic ultrasound (EUS)-guided procedure has improved the efficacy and safety of drainage of pancreatic fluid collections, which have not been well studied in pediatric populations, barring a scant volume of small case series. Excellent results of EUS-guided drainage in adult patients also need to be verified in children and adolescents. Endoprostheses used to drain pancreatic fluid collections include plastic and metal stents. Metal stents have wider lumens and become clogged less often than plastic stents. Fully covered metal stents specifically designed for pancreatic fluid collection are available, and initial studies have shown encouraging results in adult patients. The future of endoscopic management of pancreatic fluid collection in children appears promising. Prospective studies with larger sample sizes are required to establish their definitive role in the pediatric age group.

Fluid Therapy: Double-Edged Sword during Critical Care?

Science.gov (United States)

Benes, Jan; Kirov, Mikhail; Kuzkov, Vsevolod; Lainscak, Mitja; Molnar, Zsolt; Voga, Gorazd; Monnet, Xavier

2015-01-01

Fluid therapy is still the mainstay of acute care in patients with shock or cardiovascular compromise. However, our understanding of the critically ill pathophysiology has evolved significantly in recent years. The revelation of the glycocalyx layer and subsequent research has redefined the basics of fluids behavior in the circulation. Using less invasive hemodynamic monitoring tools enables us to assess the cardiovascular function in a dynamic perspective. This allows pinpointing even distinct changes induced by treatment, by postural changes, or by interorgan interactions in real time and enables individualized patient management. Regarding fluids as drugs of any other kind led to the need for precise indication, way of administration, and also assessment of side effects. We possess now the evidence that patient centered outcomes may be altered when incorrect time, dose, or type of fluids are administered. In this review, three major features of fluid therapy are discussed: the prediction of fluid responsiveness, potential harms induced by overzealous fluid administration, and finally the problem of protocol-led treatments and their timing.

Fluid Mechanics and Homeland Security

Science.gov (United States)

Settles, Gary S.

2006-01-01

Homeland security involves many applications of fluid mechanics and offers many opportunities for research and development. This review explores a wide selection of fluids topics in counterterrorism and suggests future directions. Broad topics range from preparedness and deterrence of impending terrorist attacks to detection, response, and recovery. Specific topics include aircraft hardening, blast mitigation, sensors and sampling, explosive detection, microfluidics and labs-on-a-chip, chemical plume dispersal in urban settings, and building ventilation. Also discussed are vapor plumes and standoff detection, nonlethal weapons, airborne disease spread, personal protective equipment, and decontamination. Involvement in these applications requires fluid dynamicists to think across the traditional boundaries of the field and to work with related disciplines, especially chemistry, biology, aerosol science, and atmospheric science.

The Kerr/fluid duality and the singularity of solutions to the fluid equation

International Nuclear Information System (INIS)

Fujisawa, Ippei; Nakayama, Ryuichi

2016-01-01

An equation for a viscous incompressible fluid on a spheroidal surface that is dual to the perturbation around the near-near-horizon extreme Kerr (near-NHEK) black hole is derived. It is also shown that an expansion scalar θ of a congruence of null geodesics on the perturbed horizon of the perturbed near-NHEK spacetime, which is dual to a viscous incompressible fluid, is not in general positive semidefinite, even if initial conditions on the velocity are smooth. Unless the initial conditions are appropriately adjusted, caustics of null congruence will occur on the perturbed horizon in the future. A similar result is obtained for a perturbed Schwarzschild black hole spacetime, which is dual to a viscous incompressible fluid on S 2 . An initial condition that θ be positive semidefinite at any point on S 2 is a necessary condition for the existence of smooth solutions to the incompressible Navier-Stokes equation on S 2

Fluid-structure interactions models, analysis and finite elements

CERN Document Server

Richter, Thomas

2017-01-01

This book starts by introducing the fundamental concepts of mathematical continuum mechanics for fluids and solids and their coupling. Special attention is given to the derivation of variational formulations for the subproblems describing fluid- and solid-mechanics as well as the coupled fluid-structure interaction problem. Two monolithic formulations for fluid-structure interactions are described in detail: the well-established ALE formulation and the modern Fully Eulerian formulation, which can effectively deal with problems featuring large deformation and contact. Further, the book provides details on state-of-the-art discretization schemes for fluid- and solid-mechanics and considers the special needs of coupled problems with interface-tracking and interface-capturing techniques. Lastly, advanced topics like goal-oriented error estimation, multigrid solution and gradient-based optimization schemes are discussed in the context of fluid-structure interaction problems.

Fluid Characteristics in the Giant Quartz Reef System of the Bundelkhand Craton, India: Constraints from Fluid Inclusion Study

Science.gov (United States)

Rout, D.; Panigrahi, M. K.; Pati, J. K.

2017-12-01

Giant quartz reefs are anomalous features indicating extensive mobilization of silica in the crust. Such reefs in the Abitibi belt, Canada and elsewhere are believed to be the result of activity of fluid of diverse sources on terrain boundaries. The Bundelkhand granitoid complex constituting a major part of the Bundelkhnad Craton in north-Central India is traversed by numerous such quartz reefs all across for a length of about 500 km. There are about 20 major reefs having dimensions of 35 to 40 km in length, 50 to 60 m in width standing out as prominent ridges in the region. Almost all are aligned parallel to each other in a sub-vertical to vertical manner following the NE-SW to NNE-SSW trend. Fluid inclusion petrography in quartz from these reefs reveal four types of inclusions viz. aqueous biphase (type-I), pure carbonic (type-II), aqueous carbonic (type-III) and polyphase (type-IV) inclusions. The type-I aqueous biphase inclusions are the dominant type in all the samples studied so far. Salinities calculated from temperature of melting of last ice (Tm) values are low to moderate, ranging from 0.18 to 18.19 wt% NaCl equivalents. Temperature of liquid-vapor homogenization (Th) values of these inclusions show a wide range from 101 ºC to 386 ºC (cluster around 150-250 ºC) essentially into liquid phase ruling out boiling during its course of evolution. Besides, aqueous Biphase inclusions, some data on pure CO2 inclusions furnish a near constant value of TmCO2 at -56.6 ºC in the Bundelkhand Craton indicating absence of CH4. Bivariate plot between Th and salinity suggest three possible water types which are controlling the overall activity of fluid in quartz reefs of Bundelkhand Craton viz. low-T low saline, high-T low saline and moderate-T and moderate saline. A low saline and CO2-bearing and higher temperature nature resembles a metamorphic fluid that may be a source for these giant quartz reefs. The low temperature low-salinity component could be a meteoric

Timing, predictors, and progress of third space fluid accumulation during preliminary phase fluid resuscitation in adult patients with dengue.

Science.gov (United States)

Premaratna, R; Ragupathy, A; Miththinda, J K N D; de Silva, H J

2013-07-01

Fluid leakage remains the hallmark of dengue hemorrhagic fever (DHF). The applicability of currently recommended predictors of DHF for adults with dengue is questionable as these are based on studies conducted in children. One hundred and two adults with dengue were prospectively followed up to investigate whether home-based or hospital-based early phase fluid resuscitation has an impact on clinical and hematological parameters used for the diagnosis of early or critical phase fluid leakage. In the majority of subjects, third space fluid accumulation (TSFA) was detected on the fifth and sixth days of infection. The quantity and quality of fluids administered played no role in TSFA. A reduction in systolic blood pressure appeared to be more helpful than a reduction in pulse pressure in predicting fluid leakage. TSFA occurred with lower percentage rises in packed cell volume (PCV) than stated in the current recommendations. A rapid reduction in platelets, progressive reduction in white blood cells, percentage rises in Haemoglobin (Hb), and PCV, and rises in aspartate aminotransferase and alanine aminotransferase were observed in patients with TSFA and therefore with the development of severe illness. Clinicians should be aware of the limitations of currently recommended predictors of DHF in adult patients who are receiving fluid resuscitation. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Low-frequency fluid waves in fractures and pipes

Energy Technology Data Exchange (ETDEWEB)

Korneev, Valeri

2010-09-01

Low-frequency analytical solutions have been obtained for phase velocities of symmetrical fluid waves within both an infinite fracture and a pipe filled with a viscous fluid. Three different fluid wave regimes can exist in such objects, depending on the various combinations of parameters, such as fluid density, fluid viscosity, walls shear modulus, channel thickness, and frequency. Equations for velocities of all these regimes have explicit forms and are verified by comparisons with the exact solutions. The dominant role of fractures in rock permeability at field scales and the strong amplitude and frequency effects of Stoneley guided waves suggest the importance of including these wave effects into poroelastic theories.

Tribodynamic Modeling of Digital Fluid Power Motors

DEFF Research Database (Denmark)

Johansen, Per

. In fluid power motoring and pumping units, a significant problem is that loss mechanisms do not scale down with diminishing power throughput. Although machines can reach peak efficiencies above 95%, the actual efficiency during operation, which includes part-load situations, is much lower. The invention...... of digital fluid power displacement units has been able to address this problem. The main idea of the digital fluid power displacement technology is to disable individual chambers, by use of electrical actuated valves. A displacement chamber is disabled by keeping the valve, between the chamber and the low...... design methods and tools are important to the development of digital fluid power machines. The work presented in this dissertation is part of a research program focusing on the development of digital fluid power MW-motors for use in hydraulic drive train in wind turbines. As part of this development...

Fluid Dynamics Theory, Computation, and Numerical Simulation

CERN Document Server

Pozrikidis, Constantine

2009-01-01

Fluid Dynamics: Theory, Computation, and Numerical Simulation is the only available book that extends the classical field of fluid dynamics into the realm of scientific computing in a way that is both comprehensive and accessible to the beginner. The theory of fluid dynamics, and the implementation of solution procedures into numerical algorithms, are discussed hand-in-hand and with reference to computer programming. This book is an accessible introduction to theoretical and computational fluid dynamics (CFD), written from a modern perspective that unifies theory and numerical practice. There are several additions and subject expansions in the Second Edition of Fluid Dynamics, including new Matlab and FORTRAN codes. Two distinguishing features of the discourse are: solution procedures and algorithms are developed immediately after problem formulations are presented, and numerical methods are introduced on a need-to-know basis and in increasing order of difficulty. Matlab codes are presented and discussed for ...

Non-Newtonian fluid flow in 2D fracture networks

Science.gov (United States)

Zou, L.; Håkansson, U.; Cvetkovic, V.

2017-12-01

Modeling of non-Newtonian fluid (e.g., drilling fluids and cement grouts) flow in fractured rocks is of interest in many geophysical and industrial practices, such as drilling operations, enhanced oil recovery and rock grouting. In fractured rock masses, the flow paths are dominated by fractures, which are often represented as discrete fracture networks (DFN). In the literature, many studies have been devoted to Newtonian fluid (e.g., groundwater) flow in fractured rock using the DFN concept, but few works are dedicated to non-Newtonian fluids.In this study, a generalized flow equation for common non-Newtonian fluids (such as Bingham, power-law and Herschel-Bulkley) in a single fracture is obtained from the analytical solutions for non-Newtonian fluid discharge between smooth parallel plates. Using Monte Carlo sampling based on site characterization data for the distribution of geometrical features (e.g., density, length, aperture and orientations) in crystalline fractured rock, a two dimensional (2D) DFN model is constructed for generic flow simulations. Due to complex properties of non-Newtonian fluids, the relationship between fluid discharge and the pressure gradient is nonlinear. A Galerkin finite element method solver is developed to iteratively solve the obtained nonlinear governing equations for the 2D DFN model. Using DFN realizations, simulation results for different geometrical distributions of the fracture network and different non-Newtonian fluid properties are presented to illustrate the spatial discharge distributions. The impact of geometrical structures and the fluid properties on the non-Newtonian fluid flow in 2D DFN is examined statistically. The results generally show that modeling non-Newtonian fluid flow in fractured rock as a DFN is feasible, and that the discharge distribution may be significantly affected by the geometrical structures as well as by the fluid constitutive properties.

Relativistic viscoelastic fluid mechanics

International Nuclear Information System (INIS)

Fukuma, Masafumi; Sakatani, Yuho

2011-01-01

A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.

Relativistic viscoelastic fluid mechanics.

Science.gov (United States)

Fukuma, Masafumi; Sakatani, Yuho

2011-08-01

A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.

Ludwig Prandtl and Boundary Layers in Fluid Flow

Indian Academy of Sciences (India)

His research is ... research in fluid mechan- ... For common fluids the viscous force is proportional to .... that the analogy is only a very crude, qualitative one. ..... separation is turbulent and the fluid in the wake is nearly stagnant. Method of.

Design guide for calculating fluid damping for circular cylindrical structures

International Nuclear Information System (INIS)

Chen, S.S.

1983-06-01

Fluid damping plays an important role for structures submerged in fluid, subjected to flow, or conveying fluid. This design guide presents a summary of calculational procedures and design data for fluid damping for circular cylinders vibrating in quiescent fluid, crossflow, and parallel flow

Studying Validity of Single-Fluid Model in Inertial Confinement Fusion

International Nuclear Information System (INIS)

Gu Jian-Fa; Fan Zheng-Feng; Dai Zhen-Sheng; Ye Wen-Hua; Pei Wen-Bing; Zhu Shao-Ping

2014-01-01

The validity of single-fluid model in inertial confinement fusion simulations is studied by comparing the results of the multi- and single-fluid models. The multi-fluid model includes the effects of collision and interpenetration between fluid species. By simulating the collision of fluid species, steady-state shock propagation into the thin DT gas and expansion of hohlraum Au wall heated by lasers, the results show that the validity of single-fluid model is strongly dependent on the ratio of the characteristic length of the simulated system to the particle mean free path. When the characteristic length L is one order larger than the mean free path λ, the single-fluid model's results are found to be in good agreement with the multi-fluid model's simulations, and the modeling of single-fluid remains valid. If the value of L/λ is lower than 10, the interpenetration between fluid species is significant, and the single-fluid simulations show some unphysical results; while the multi-fluid model can describe well the interpenetration and mix phenomena, and give more reasonable results. (physics of gases, plasmas, and electric discharges)

Development of a test facility for analyzing supercritical fluid blowdown

International Nuclear Information System (INIS)

Roberto, Thiago D.; Alvim, Antonio C.M.

2015-01-01

The generation IV nuclear reactors under development mostly use supercritical fluids as the working fluid because higher temperatures improve the thermal efficiency. Supercritical fluids are used by modern nuclear power plants to achieve thermal efficiencies of around 45%. With water as the supercritical working fluid, these plants operate at a high temperature and pressure. However, experiments on supercritical water are limited by technical and financial difficulties. These difficulties can be overcome by using model fluids, which have more feasible supercritical conditions and exhibit a lower critical pressure and temperature. Experimental research is normally used to determine the conditions under which model fluids represent supercritical fluids under steady-state conditions. A fluid-to-fluid scaling approach has been proposed to determine model fluids that can represent supercritical fluids in a transient state. This paper presents an application of fractional scale analysis to determine the simulation parameters for a depressurization test facility. Carbon dioxide (CO 2 ) and R134a gas were considered as the model fluids because their critical point conditions are more feasible than those of water. The similarities of water (prototype), CO 2 (model) and R134a (model) for depressurization in a pressure vessel were analyzed. (author)

Challenges with Tertiary-Level Mechatronic Fluid Power

DEFF Research Database (Denmark)

Dransfield, Peter; Conrad, Finn

1996-01-01

As authors we take the view that mechatronics, as it relates to fluid power, has three levels which we designate as primary, secondary and tertiary. A brief review of the current status of fluid power, hydraulic and pneumatic, and of electronic control of it is presented and discussed. The focus...... is then on tertiary-level mechatronic fluid power and the challenges to it being applied successfully....

Pancreatitis-associated fluid collections involving the spleen

International Nuclear Information System (INIS)

Vick, C.W.; Simeone, J.F.; Ferrucci, J.T. Jr.; Wittenberg, J.; Mueller, P.R.; Harvard Medical School, Boston, MA

1981-01-01

The clinical and radiographic features of 2 patients with dissecting pancreatitis-associated fluid collections involving the spleen are described. A typical appearance of left upper quadrant fluid collection lateral to the splenic pulp was observed by ultrasonography (US) or computed body tomography (CBT). Although these findings are nonspecific, a left upper quadrant fluid collection may be characterized definitively by US/CBT-guided needle aspiration. (orig.)

Mixed Fluid Conditions: Capillary Phenomena

KAUST Repository

Santamarina, Carlos

2017-07-06

Mixed fluid phenomena in porous media have profound implications on soil-atmosphere interaction, energy geotechnology, environmental engineering and infrastructure design. Surface tension varies with pressure, temperature, solute concentration, and surfactant concentration; on the other hand, the contact angle responds to interfacial tensions, surface topography, invasion velocity, and chemical interactions. Interfaces are not isolated but interact through the fluid pressure and respond to external fields. Jumps, snap-offs and percolating wetting liquids along edges and crevices are ubiquitous in real, non-cylindrical porous networks. Pore- and macroscale instabilities together with pore structure variability-and-correlation favor fluid trapping and hinder recovery efficiency. The saturation-pressure characteristic curve is affected by the saturation-history, flow-rate, the mechanical response of the porous medium, and time-dependent reactive and diffusive processes; in addition, there are salient differences between unsaturation by internal gas nucleation and gas invasion. Capillary forces add to other skeletal forces in the porous medium and can generate open-mode discontinuities when the capillary entry pressure is high relative to the effective stress. Time emerges as an important variable in mixed-fluid conditions and common quasi-static analyses may fail to capture the system response.

Tactic-specific differences in seminal fluid influence sperm performance.

Science.gov (United States)

Locatello, Lisa; Poli, Federica; Rasotto, Maria B

2013-03-22

Seminal fluid often makes up a large part of an ejaculate, yet most empirical and theoretical studies on sperm competition have focused on how sperm characteristics (number and quality) affect fertilization success. However, seminal fluid influences own sperm performance and may potentially influence the outcome of sperm competition, by also affecting that of rivals. As a consequence males may be expected to allocate their investment in both sperm and seminal fluid in relation to the potential level of competition. Grass goby (Zosterisessor ophiocephalus) is an external fertilizer with guard-sneaker mating tactics, where sperm competition risk varies according to the tactic adopted. Here, we experimentally manipulated grass goby ejaculates by separately combining sperm and seminal fluid from territorial and sneaker males. While sperm of sneaker and territorial males did not differ in their performance when they interacted with their own seminal fluid only, sperm of sneakers increased their velocity and fertilization rate in the presence of territorial males' seminal fluid. By contrast, sneaker males' seminal fluid had a detrimental effect on the performance of territorial males' sperm. Sperm velocity was unaffected by the seminal fluid of males employing the same tactic, suggesting that seminal fluid's effect on rival-tactic sperm is not based on a self/non-self recognition mechanism. Our findings show that cross interactions of sperm and seminal fluid may influence the fertilization success of competing ejaculates with males investing in both sperm and seminal fluid in response to sperm competition risk.

Upper mantle fluids evolution, diamond formation, and mantle metasomatism

Science.gov (United States)

Huang, F.; Sverjensky, D. A.

2017-12-01

During mantle metasomatism, fluid-rock interactions in the mantle modify wall-rock compositions. Previous studies usually either investigated mineral compositions in xenoliths and xenocrysts brought up by magmas, or examined fluid compositions preserved in fluid inclusions in diamonds. However, a key study of Panda diamonds analysed both mineral and fluid inclusions in the diamonds [1] which we used to develop a quantitative characterization of mantle metasomatic processes. In the present study, we used an extended Deep Earth Water model [2] to simulate fluid-rock interactions at upper mantle conditions, and examine the fluids and mineral assemblages together simultaneously. Three types of end-member fluids in the Panda diamond fluid inclusions include saline, rich in Na+K+Cl; silicic, rich in Si+Al; and carbonatitic, rich in Ca+Mg+Fe [1, 3]. We used the carbonatitic end-member to represent fluid from a subducting slab reacting with an excess of peridotite + some saline fluid in the host environment. During simultaneous fluid mixing and reaction with the host rock, the logfO2 increased by about 1.6 units, and the pH increased by 0.7 units. The final minerals were olivine, garnet and diamond. The Mg# of olivine decreased from 0.92 to 0.85. Garnet precipitated at an early stage, and its Mg# also decreased with reaction progress, in agreement with the solid inclusions in the Panda diamonds. Phlogopite precipitated as an intermediate mineral and then disappeared. The aqueous Ca, Mg, Fe, Si and Al concentrations all increased, while Na, K, and Cl concentrations decreased during the reaction, consistent with trends in the fluid inclusion compositions. Our study demonstrates that fluids coming from subducting slabs could trigger mantle metasomatism, influence the compositions of sub-lithospherc cratonic mantle, precipitate diamonds, and change the oxygen fugacity and pH of the upper mantle fluids. [1] Tomlinson et al. EPSL (2006); [2] Sverjensky, DA et al., GCA (2014

Invasion of Hydrous Fluids Predates Kimberlite Formation

Science.gov (United States)

Kopylova, M. G.; Wang, Q.; Smith, E. M.

2017-12-01

Petrological observations on diamonds and peridotite xenoliths in kimberlites point towards an influx of hydrous metasomatic fluids shortly predating kimberlite formation. Diamonds may grow at different times within the same segment of the cratonic mantle, and diamonds that form shortly before (diamonds typically contain 10-25 wt.% water in fluid inclusions, while older octahedrally-grown diamonds host "dry" N2-CO2 fluids. Our recent studies of fluids in diamond now show that many different kinds of diamonds can contain fluid inclusions. Specifically, we found a new way to observe and analyze fluids in octahedrally-grown, non-fibrous diamonds by examining healed fractures. This is a new textural context for fluid inclusions that reveals a valuable physical record of infiltrating mantle fluids, that postdate diamond growth, but equilibrate within the diamond stability field at depths beyond 150 km. Another sign of the aqueous fluids influx is the formation of distinct peridotite textures shortly predating the kimberlite. Kimberlites entrain peridotite xenoliths with several types of textures: older coarse metamorphic textures and younger, sheared textures. The preserved contrast in grain sizes between porphyroclasts and neoblasts in sheared peridotites constrain the maximum duration of annealing. Experimental estimates of the annealing time vary from 7x107 sec (2 years) to 106 years (1 My) depending on olivine hydration, strain rate, pressure, temperature and, ultimately, the annealing mechanism. Kimberlite sampling of sheared peridotites from the lithosphere- asthenosphere boundary (LAB) implies their formation no earlier than 1 My prior to the kimberlite ascent. Water contents of olivine measured by FTIR spectrometry using polarized light demonstrated contrasting hydration of coarse and sheared samples. Olivine from sheared peridotite samples has the average water content of 78±3 ppm, in contrast to the less hydrated coarse peridotites (33±6 ppm). LAB hydration

Wormhole solutions sourced by fluids, II: three-fluid two-charged sources

Energy Technology Data Exchange (ETDEWEB)

Azreg-Ainou, Mustapha [Baskent University, Faculty of Engineering, Ankara (Turkey)

2016-01-15

Lack of a consistent metric for generating rotating wormholes motivates us to present a new one endowed with interesting physical and geometrical properties. When combined with the generalized method of superposition of fields, which consists in attaching a form of matter to each moving frame, it generates massive and charged (charge without charge) two-fluid-sourced, massive and two-charged three-fluid-sourced, rotating as well as new static wormholes which, otherwise, can hardly be derived by integration. If the lapse function of the static wormhole is bounded from above, no closed timelike curves occur in the rotating counterpart. For positive energy densities dying out faster than 1/r, the angular velocity includes in its expansion a correction term, to the leading one that corresponds to ordinary stars, proportional to ln r/r{sup 4}. Such a term is not present in the corresponding expansion for the Kerr-Newman black hole. Based on this observation and our previous work, the dragging effects of falling neutral objects may constitute a substitute for other known techniques used for testing the nature of the rotating black hole candidates that are harbored in the center of galaxies. We discuss the possibility of generating (n + 1)-fluid-sourced, n-charged, rotating as well as static wormholes. (orig.)

Wormhole solutions sourced by fluids, II: three-fluid two-charged sources

Energy Technology Data Exchange (ETDEWEB)

Azreg-Aïnou, Mustapha, E-mail: azreg@baskent.edu.tr [Faculty of Engineering, Başkent University, Bağlıca Campus, 06810, Ankara (Turkey)

2016-01-05

Lack of a consistent metric for generating rotating wormholes motivates us to present a new one endowed with interesting physical and geometrical properties. When combined with the generalized method of superposition of fields, which consists in attaching a form of matter to each moving frame, it generates massive and charged (charge without charge) two-fluid-sourced, massive and two-charged three-fluid-sourced, rotating as well as new static wormholes which, otherwise, can hardly be derived by integration. If the lapse function of the static wormhole is bounded from above, no closed timelike curves occur in the rotating counterpart. For positive energy densities dying out faster than 1 / r, the angular velocity includes in its expansion a correction term, to the leading one that corresponds to ordinary stars, proportional to lnr/r{sup 4}. Such a term is not present in the corresponding expansion for the Kerr–Newman black hole. Based on this observation and our previous work, the dragging effects of falling neutral objects may constitute a substitute for other known techniques used for testing the nature of the rotating black hole candidates that are harbored in the center of galaxies. We discuss the possibility of generating (n+1)-fluid-sourced, n-charged, rotating as well as static wormholes.

Fluid Dynamics And Mass Transfer In Two-Fluid Taylor-Couette Flow

International Nuclear Information System (INIS)

Baier, G.; Graham, M.D.

1998-01-01

The Taylor-Couette instability of a single liquid phase can be used to enhance mass transfer processes such as filtration and membrane separations. We consider here the possibility of using this instability to enhance interphase transport in a two-fluid systems, with a view toward improved liquid-liquid extractions for biotechnology applications. We investigate the centrifugal instability of a pair of radially stratified immiscible liquids in the annular gap between concentric, corotating cylinders: two-fluid Taylor-Couette flow. Experiments show that a two-layer flow with a well-defined interface and Taylor vortices in each phase can be obtained. The experimental results are in good agreement with predictions of inviscid arguments based on a two-phase extension of Rayleigh's criterion, as well as with detailed linear stability calculations. For a given geometry, the most stable configuration occurs for fluids of roughly (exactly in the inviscid limit) equal dynamic viscosities. A number of preliminary mass transfer experiments have also been performed, in the presence of axial counterflow. The onset of Taylor vortices coincides with a clear decrease in the extent of axial dispersion and an increase in the rate of interphase transport, thus suggesting that this flow geometry may provide an effective means for countercurrent chromatographic separations

Micro/Nanospheres Generation by Fluid-Fluid Interaction Technology: A Literature Review.

Science.gov (United States)

Lei, Lei; Bergstrom, Don; Zhang, Bing; Zhang, Hongbo; Yin, Ruixue; Song, Ki-Young; Zhang, Wenjun

2017-01-01

This review focuses on the fundamental fluid mechanics which governs the generation of micro/nanospheres. The micro/nanosphere generation process has gathered significant attention in the past two decades, since micro/nanospheres are widely used in drug delivery, food science, cosmetics, and other application areas. Many methods have been developed based on different operating principles, such as microfluidic methods, electrospray methods, chemical methods, and so forth. This paper focuses on microfluidic methods. Although the structure of the microfluidic devices may be different, the operating principles behind them are often very similar. Following an initial discussion of the fluid mechanics related to the generation of microspheres, various design approaches are discussed, including T-junction, flow focusing, membrane emulsification, modified T-junction, and double emulsification methods. The advantages and problems associated with each method are also discussed. Next, the most commonly used computational fluid dynamics (CFD) methods are reviewed at three different levels: microscopic, mesoscopic, and macroscopic. Finally, the issues identified in the current literature are discussed, and some suggestions are offered regarding the future direction of technology development related to micro/nanosphere generation. Few relevant patents to the topic have been reviewed and cited. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Computational fluid dynamics study of viscous fingering in supercritical fluid chromatography.

Science.gov (United States)

Subraveti, Sai Gokul; Nikrityuk, Petr; Rajendran, Arvind

2018-01-26

Axi-symmetric numerical simulations are carried out to study the dynamics of a plug introduced through a mixed-stream injection in supercritical fluid chromatographic columns. The computational fluid dynamics model developed in this work takes into account both the hydrodynamics and adsorption equilibria to describe the phenomena of viscous fingering and plug effect that contribute to peak distortions in mixed-stream injections. The model was implemented into commercial computational fluid dynamics software using user-defined functions. The simulations describe the propagation of both the solute and modifier highlighting the interplay between the hydrodynamics and plug effect. The simulated peaks showed good agreement with experimental data published in the literature involving different injection volumes (5 μL, 50 μL, 1 mL and 2 mL) of flurbiprofen on Chiralpak AD-H column using a mobile phase of CO 2 and methanol. The study demonstrates that while viscous fingering is the main source of peak distortions for large-volume injections (1 mL and 2 mL) it has negligible impact on small-volume injections (5 μL and 50 μL). Band broadening in small-volume injections arise mainly due to the plug effect. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Mechanics of fluid flow

CERN Document Server

Basniev, Kaplan S; Chilingar, George V 0

2012-01-01

The mechanics of fluid flow is a fundamental engineering discipline explaining both natural phenomena and human-induced processes, and a thorough understanding of it is central to the operations of the oil and gas industry.  This book, written by some of the world's best-known and respected petroleum engineers, covers the concepts, theories, and applications of the mechanics of fluid flow for the veteran engineer working in the field and the student, alike.  It is a must-have for any engineer working in the oil and gas industry.

Correlation of cutting fluid performance in different machining operations

DEFF Research Database (Denmark)

De Chiffre, Leonardo; Belluco, Walter

2001-01-01

An analysis of cutting fluid performance in different metal cutting operations is presented, based on experimental investigations in which type of operation, performance criteria, work material, and fluid type are considered. Cutting fluid performance was evaluated in turning, drilling, reaming...... investigated. Results show that correlation of cutting fluid performance in different operations exists, within the same group of cutting fluids, in the case of stainless steel as workpiece material. Under the tested conditions, the average correlation coefficients between efficiency parameters with different...... operations on austenitic stainless steel lied in the range 0.87-0.97 for waterbased fluids and 0.79-0.89 for straight oils. A similar correlation could not be found for the other workpiece materials investigated in this work. A rationalisation of cutting fluid performance tests is suggested....

Scale interactions in compressible rotating fluids

Czech Academy of Sciences Publication Activity Database

Feireisl, Eduard; Novotný, A.

2014-01-01

Roč. 193, č. 6 (2014), s. 1703-1725 ISSN 0373-3114 Keywords : compressible fluid * rotating fluid * singular limit Subject RIV: BA - General Mathematics Impact factor: 1.065, year: 2014 http://link.springer.com/article/10.1007%2Fs10231-013-0353-7

Vortex dynamics in the two-fluid model

International Nuclear Information System (INIS)

Thouless, D. J.; Geller, M. R.; Vinen, W. F.; Fortin, J.-Y.; Rhee, S. W.

2001-01-01

We have used two-fluid dynamics to study the discrepancy between the work of Thouless, Ao, and Niu (TAN) and that of Iordanskii. In TAN no transverse force on a vortex due to normal fluid flow was found, whereas the earlier work found a transverse force proportional to normal fluid velocity u n and normal fluid density ρ n . We have linearized the time-independent two-fluid equations about the exact solution for a vortex, and find three solutions that are important in the region far from the vortex. Uniform superfluid flow gives rise to the usual superfluid Magnus force. Uniform normal fluid flow gives rise to no forces in the linear region, but does not satisfy reasonable boundary conditions at short distances. A logarithmically increasing normal fluid flow gives a viscous force. As in classical hydrodynamics, and as in the early work of Hall and Vinen, this logarithmic increase must be cut off by nonlinear effects at large distances; this gives a viscous force proportional to u n /lnu n , and a transverse contribution that goes like u n /(lnu n ) 2 , even in the absence of an explicit Iordanskii force. In the limit u n ->0 the TAN result is obtained, but at nonzero u n there are important corrections that were not found in TAN. We argue that the Magnus force in a superfluid at nonzero temperature is an example of a topological relation for which finite-size corrections may be large

Optimizing drilling performance using a selected drilling fluid

Science.gov (United States)

Judzis, Arnis [Salt Lake City, UT; Black, Alan D [Coral Springs, FL; Green, Sidney J [Salt Lake City, UT; Robertson, Homer A [West Jordan, UT; Bland, Ronald G [Houston, TX; Curry, David Alexander [The Woodlands, TX; Ledgerwood, III, Leroy W.

2011-04-19

To improve drilling performance, a drilling fluid is selected based on one or more criteria and to have at least one target characteristic. Drilling equipment is used to drill a wellbore, and the selected drilling fluid is provided into the wellbore during drilling with the drilling equipment. The at least one target characteristic of the drilling fluid includes an ability of the drilling fluid to penetrate into formation cuttings during drilling to weaken the formation cuttings.

Collection of apoplastic fluids from Arabidopsis thaliana leaves

DEFF Research Database (Denmark)

Madsen, Svend Roesen; Nour-Eldin, Hussam Hassan; Halkier, Barbara Ann

2016-01-01

The leaf apoplast comprises the extracellular continuum outside cell membranes. A broad range of processes take place in the apoplast, including intercellular signaling, metabolite transport, and plant-microbe interactions. To study these processes, it is essential to analyze the metabolite conte...... in apoplastic fluids. Due to the fragile nature of leaf tissues, it is a challenge to obtain apoplastic fluids from leaves. Here, methods to collect apoplastic washing fluid and guttation fluid from Arabidopsis thaliana leaves are described....

The influence of tip clearance on performance and internal flow condition of fluid food pump using low viscous fluid

International Nuclear Information System (INIS)

Kubo, S; Ishioka, T; Fukutomi, J; Shigemitsu, T

2012-01-01

Fluid machines for fluid food have been used in wide variety of fields i.e. transportation, the filling, and for the improvement of quality of fluid foods. However, flow conditions of it are quite complicated because fluid foods are different from water. Therefore, design methods based on internal flow conditions have not been conducted. In this research, turbo-pumps having a small number of blades were used to decrease shear loss and keep wide flow passage. The influence of the tip clearance was investigated by the numerical analysis using the model with and without the tip clearance. In this paper, the influence of tip clearance on performances and internal flow conditions of turbo-pump using low viscous fluid were clarified by experimental and numerical analysis results. In addition, design methods based on the internal flow were considered. Further, the influences of viscosity on the performance characteristic and internal flow were investigated.

Hydrodynamic cavitation in Stokes flow of anisotropic fluids

Science.gov (United States)

Stieger, Tillmann; Agha, Hakam; Schoen, Martin; Mazza, Marco G.; Sengupta, Anupam

2017-05-01

Cavitation, the nucleation of vapour in liquids, is ubiquitous in fluid dynamics, and is often implicated in a myriad of industrial and biomedical applications. Although extensively studied in isotropic liquids, corresponding investigations in anisotropic liquids are largely lacking. Here, by combining liquid crystal microfluidic experiments, nonequilibrium molecular dynamics simulations and theoretical arguments, we report flow-induced cavitation in an anisotropic fluid. The cavitation domain nucleates due to sudden pressure drop upon flow past a cylindrical obstacle within a microchannel. For an anisotropic fluid, the inception and growth of the cavitation domain ensued in the Stokes regime, while no cavitation was observed in isotropic liquids flowing under similar hydrodynamic parameters. Using simulations we identify a critical value of the Reynolds number for cavitation inception that scales inversely with the order parameter of the fluid. Strikingly, the critical Reynolds number for anisotropic fluids can be 50% lower than that of isotropic fluids.

High-pressure fluid phase equilibria phenomenology and computation

CERN Document Server

Deiters, Ulrich K

2012-01-01

The book begins with an overview of the phase diagrams of fluid mixtures (fluid = liquid, gas, or supercritical state), which can show an astonishing variety when elevated pressures are taken into account; phenomena like retrograde condensation (single and double) and azeotropy (normal and double) are discussed. It then gives an introduction into the relevant thermodynamic equations for fluid mixtures, including some that are rarely found in modern textbooks, and shows how they can they be used to compute phase diagrams and related properties. This chapter gives a consistent and axiomatic approach to fluid thermodynamics; it avoids using activity coefficients. Further chapters are dedicated to solid-fluid phase equilibria and global phase diagrams (systematic search for phase diagram classes). The appendix contains numerical algorithms needed for the computations. The book thus enables the reader to create or improve computer programs for the calculation of fluid phase diagrams. introduces phase diagram class...

Statistical mechanics of homogeneous partly pinned fluid systems.

Science.gov (United States)

Krakoviack, Vincent

2010-12-01

The homogeneous partly pinned fluid systems are simple models of a fluid confined in a disordered porous matrix obtained by arresting randomly chosen particles in a one-component bulk fluid or one of the two components of a binary mixture. In this paper, their configurational properties are investigated. It is shown that a peculiar complementarity exists between the mobile and immobile phases, which originates from the fact that the solid is prepared in presence of and in equilibrium with the adsorbed fluid. Simple identities follow, which connect different types of configurational averages, either relative to the fluid-matrix system or to the bulk fluid from which it is prepared. Crucial simplifications result for the computation of important structural quantities, both in computer simulations and in theoretical approaches. Finally, possible applications of the model in the field of dynamics in confinement or in strongly asymmetric mixtures are suggested.

Heat transfers and related effects in supercritical fluids

CERN Document Server

Zappoli, Bernard; Garrabos, Yves

2015-01-01

This book investigates the unique hydrodynamics and heat transfer problems that are encountered in the vicinity of the critical point of fluids. Emphasis is given on weightlessness conditions, gravity effects and thermovibrational phenomena. Near their critical point, fluids indeed obey universal behavior and become very compressible and expandable. Their comportment, when gravity effects are suppressed, becomes quite unusual. The problems that are treated in this book are of interest to students and researchers interested in the original behavior of near-critical fluids as well as to engineers that have to manage supercritical fluids. A special chapter is dedicated to the present knowledge of critical point phenomena. Specific data for many fluids are provided, ranging from cryogenics (hydrogen) to high temperature (water). Basic information in statistical mechanics, mathematics and measurement techniques is also included. The basic concepts of fluid mechanics are given for the non-specialists to be able to ...

Fluid curtailment during childhood diarrhea: a countdown analysis.

Science.gov (United States)

Perin, Jamie; Carvajal-Velez, Liliana; Carter, Emily; Bryce, Jennifer; Newby, Holly

2015-06-26

The foundation of recommended diarrhea management in young children is increased fluids and continued feeding. This increase in fluids is necessary to replace those lost during diarrhea and ultimately prevent dehydration. There may be an opportunity to prevent deaths in children under five by discouraging the practice of reducing or curtailing fluids during diarrhea episodes across different settings worldwide. We quantify and describe the extent of fluid curtailment in children with diarrhea in a selection of countries (Burkina Faso, Democratic Republic of Congo, Ethiopia, Nigeria, Tanzania, and Uganda) with high burden of diarrhea-related mortality with national cross sectional survey data. We examine the practice of fluid curtailment in these countries and its relationship to child and household traits and to characteristics of diarrhea management. The prevalence of fluid curtailment among children under five with diarrhea is strikingly high in these countries: 55 % in Nigeria, 49 % in Ethiopia, 44 % in Uganda, 37 % in Tanzania, 36 % in DR Congo and 32 % in Burkina Faso. Fluid curtailment is associated with giving less food, potentially worsening the impact of this harmful practice. Children who were reported to have had fluids curtailed during diarrhea episodes were also 3.51 (95 % confidence, 2.66 - 4.64) times more likely to be reported to have food withheld (α = 0.05; p water source. Children of poorer or less educated mothers and those living in rural areas are more likely to have curtailed fluids, compared to children of less poor or more educated mothers, or those living in urban areas. The harmful practice of curtailing fluids for a child with diarrhea is highly prevalent, representing an increased risk of dehydration and complications due to diarrhea, including death, especially for children in specific subgroups.

Time-Dependent Thermally-Driven Interfacial Flows in Multilayered Fluid Structures

Science.gov (United States)

Haj-Hariri, Hossein; Borhan, A.

1996-01-01

A computational study of thermally-driven convection in multilayered fluid structures will be performed to examine the effect of interactions among deformable fluid-fluid interfaces on the structure of time-dependent flow in these systems. Multilayered fluid structures in two models configurations will be considered: the differentially heated rectangular cavity with a free surface, and the encapsulated cylindrical liquid bridge. An extension of a numerical method developed as part of our recent NASA Fluid Physics grant will be used to account for finite deformations of fluid-fluid interfaces.

Fluid inclusion brine compositions from Palo Duro Basin salt sites

International Nuclear Information System (INIS)

Moody, J.B.

1987-01-01

The fluid inclusion analyses were done on salt samples from Lower San Andres Cycle 4 and 5. The stable isotope composition of the fluid inclusion brines was measured on duplicate samples taken from the same fluid inclusion brine for correlation of geochemical content with the stable isotopic content. The analyzed Palo Duro Basin salt fluid inclusions are predominantly one phase, i.e., the presence of a fluid only. However, many of the larger fluid inclusions do have a small vapor bubble. This liquid/vapor ratio is so high in these vapor-containing fluid inclusions that their behavior in a thermal gradient would be almost identical to that of all liquid inclusions. Closely associated with the fluid inclusions are cryptomelane where some fibers penetrate into halite host crystal. The fluid inclusions have a wide variability in content for those components that were analyzed, even within the same salt type. The fluid inclusion brines are also acidic, ranging from 3 to 6 as measured with pH test papers

Hamiltonian formalism for perfect fluids in general relativity

International Nuclear Information System (INIS)

Demaret, J.; Moncrief, V.

1980-01-01

Schutz's Hamiltonian theory of a relativistic perfect fluid, based on the velocity-potential version of classical perfect fluid hydrodynamics as formulated by Seliger and Whitham, is used to derive, in the framework of the Arnowitt, Deser, and Misner (ADM) method, a general partially reduced Hamiltonian for relativistic systems filled with a perfect fluid. The time coordinate is chosen, as in Lund's treatment of collapsing balls of dust, as minus the only velocity potential different from zero in the case of an irrotational and isentropic fluid. A ''semi-Dirac'' method can be applied to quantize astrophysical and cosmological models in the framework of this partially reduced formalism. If one chooses Taub's adapted comoving coordinate system, it is possible to derive a fully reduced ADM Hamiltonian, which is equal to minus the total baryon number of the fluid, generalizing a result previously obtained by Moncrief in the more particular framework of Taub's variational principle, valid for self-gravitating barotropic relativistic perfect fluids. An unconstrained Hamiltonian density is then explicitly derived for a fluid obeying the equation of state p=(gamma-1)rho (1 < or = γ < or = 2), which can adequately describe the phases of very high density attained in a catastrophic collapse or during the early stages of the Universe. This Hamiltonian density, shown to be equivalent to Moncrief's in the particular case of an isentropic fluid, can be simplified for fluid-filled class-A diagonal Bianchi-type cosmological models and appears as a suitable starting point for the study of the canonical quantization of these models

Hamiltonian description of the ideal fluid

International Nuclear Information System (INIS)

Morrison, P.J.

1998-01-01

The Hamiltonian viewpoint of fluid mechanical systems with few and infinite number of degrees of freedom is described. Rudimentary concepts of finite-degree-of-freedom Hamiltonian dynamics are reviewed, in the context of the passive advection of a scalar or tracer field by a fluid. The notions of integrability, invariant-tori, chaos, overlap criteria, and invariant-tori breakup are described in this context. Preparatory to the introduction of field theories, systems with an infinite number of degrees of freedom, elements of functional calculus and action principles of mechanics are reviewed. The action principle for the ideal compressible fluid is described in terms of Lagrangian or material variables. Hamiltonian systems in terms of noncanonical variables are presented, including several examples of Eulerian or inviscid fluid dynamics. Lie group theory sufficient for the treatment of reduction is reviewed. The reduction from Lagrangian to Eulerian variables is treated along with Clebsch variable decompositions. Stability in the canonical and noncanonical Hamiltonian contexts is described. Sufficient conditions for stability, such as Rayleigh-like criteria, are seen to be only sufficient in the general case because of the existence of negative-energy modes, which are possessed by interesting fluid equilibria. Linearly stable equilibria with negative energy modes are argued to be unstable when nonlinearity or dissipation is added. The energy-Casimir method is discussed and a variant of it that depends upon the notion of dynamical accessibility is described. The energy content of a perturbation about a general fluid equilibrium is calculated using three methods. copyright 1998 The American Physical Society

Active chiral fluids.

Science.gov (United States)

Fürthauer, S; Strempel, M; Grill, S W; Jülicher, F

2012-09-01

Active processes in biological systems often exhibit chiral asymmetries. Examples are the chirality of cytoskeletal filaments which interact with motor proteins, the chirality of the beat of cilia and flagella as well as the helical trajectories of many biological microswimmers. Here, we derive constitutive material equations for active fluids which account for the effects of active chiral processes. We identify active contributions to the antisymmetric part of the stress as well as active angular momentum fluxes. We discuss four types of elementary chiral motors and their effects on a surrounding fluid. We show that large-scale chiral flows can result from the collective behavior of such motors even in cases where isolated motors do not create a hydrodynamic far field.

Multivariate Associations of Fluid Intelligence and NAA.

Science.gov (United States)

Nikolaidis, Aki; Baniqued, Pauline L; Kranz, Michael B; Scavuzzo, Claire J; Barbey, Aron K; Kramer, Arthur F; Larsen, Ryan J

2017-04-01

Understanding the neural and metabolic correlates of fluid intelligence not only aids scientists in characterizing cognitive processes involved in intelligence, but it also offers insight into intervention methods to improve fluid intelligence. Here we use magnetic resonance spectroscopic imaging (MRSI) to measure N-acetyl aspartate (NAA), a biochemical marker of neural energy production and efficiency. We use principal components analysis (PCA) to examine how the distribution of NAA in the frontal and parietal lobes relates to fluid intelligence. We find that a left lateralized frontal-parietal component predicts fluid intelligence, and it does so independently of brain size, another significant predictor of fluid intelligence. These results suggest that the left motor regions play a key role in the visualization and planning necessary for spatial cognition and reasoning, and we discuss these findings in the context of the Parieto-Frontal Integration Theory of intelligence. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The Imperfect Fluid behind Kinetic Gravity Braiding

CERN Document Server

Pujolas, Oriol; Vikman, Alexander

2011-01-01

We present a standard hydrodynamical description for non-canonical scalar field theories with kinetic gravity braiding. In particular, this picture applies to the simplest galileons and k-essence. The fluid variables not only have a clear physical meaning but also drastically simplify the analysis of the system. The fluid carries charges corresponding to shifts in field space. This shift-charge current contains a spatial part responsible for diffusion of the charges. Moreover, in the incompressible limit, the equation of motion becomes the standard diffusion equation. The fluid is indeed imperfect because the energy flows neither along the field gradient nor along the shift current. The fluid has zero vorticity and is not dissipative: there is no entropy production, the energy-momentum is exactly conserved, the temperature vanishes and there is no shear viscosity. Still, in an expansion around a perfect fluid one can identify terms which correct the pressure in the manner of bulk viscosity. We close by formul...

Fluid mechanics a geometrical point of view

CERN Document Server

Rajeev, S G

2018-01-01

Fluid Mechanics: A Geometrical Point of View emphasizes general principles of physics illustrated by simple examples in fluid mechanics. Advanced mathematics (e.g., Riemannian geometry and Lie groups) commonly used in other parts of theoretical physics (e.g. General Relativity or High Energy Physics) are explained and applied to fluid mechanics. This follows on from the author's book Advanced Mechanics (Oxford University Press, 2013). After introducing the fundamental equations (Euler and Navier-Stokes), the book provides particular cases: ideal and viscous flows, shocks, boundary layers, instabilities, and transients. A restrained look at integrable systems (KdV) leads into a formulation of an ideal fluid as a hamiltonian system. Arnold's deep idea, that the instability of a fluid can be understood using the curvature of the diffeomorphism group, will be explained. Leray's work on regularity of Navier-Stokes solutions, and the modern developments arising from it, will be explained in language for physicists...

Fluid Effects in Polymers and Polymeric Composites

CERN Document Server

Weitsman, Y Jack

2012-01-01

Fluid Effects in Polymers and Polymeric Composites, written by the late Dr. Y. Jack Weitsman, addresses the wide range of parameters that affect the interaction of fluids with polymers and polymeric composites. The book aims at broadening the scope of available data, mostly limited up to this time to weight-gain recordings of fluid ingress into polymers and composites, to the practical circumstances of fluctuating exposure. Various forms of experimental data are given, in conjunction with theoretical models derived from basic scientific principles, and correlated with severity of exposure conditions and interpreted by means of rationally based theoretical models. The practical implications of the effects of fluids are discussed. The issue of fluid effects on polymers and polymeric composites is of concern to engineers and scientists active in aerospace and naval structures, as an increasing portion of these structures are made of polymeric composites and employ polymeric adhesives as a joining device. While...

Behavior of fluids in a weightless environment

Science.gov (United States)

Fester, D. A.; Eberhardt, R. N.; Tegart, J. R.

1977-01-01

Fluid behavior in a low-g environment is controlled primarily by surface tension forces. Certain fluid and system characteristics determine the magnitude of these forces for both a free liquid surface and liquid in contact with a solid. These characteristics, including surface tension, wettability or contact angle, system geometry, and the relationships governing their interaction, are discussed. Various aspects of fluid behavior in a low-g environment are then presented. This includes the formation of static interface shapes, oscillation and rotation of drops, coalescence, the formation of foams, tendency for cavitation, and diffusion in liquids which were observed during the Skylab fluid mechanics science demonstrations. Liquid reorientation and capillary pumping to establish equilibrium configurations for various system geometries, observed during various free-fall (drop-tower) low-g tests, are also presented. Several passive low-g fluid storage and transfer systems are discussed. These systems use surface tension forces to control the liquid/vapor interface and provide gas-free liquid transfer and liquid-free vapor venting.

Fluid dynamics theory, computation, and numerical simulation

CERN Document Server

Pozrikidis, C

2001-01-01

Fluid Dynamics Theory, Computation, and Numerical Simulation is the only available book that extends the classical field of fluid dynamics into the realm of scientific computing in a way that is both comprehensive and accessible to the beginner The theory of fluid dynamics, and the implementation of solution procedures into numerical algorithms, are discussed hand-in-hand and with reference to computer programming This book is an accessible introduction to theoretical and computational fluid dynamics (CFD), written from a modern perspective that unifies theory and numerical practice There are several additions and subject expansions in the Second Edition of Fluid Dynamics, including new Matlab and FORTRAN codes Two distinguishing features of the discourse are solution procedures and algorithms are developed immediately after problem formulations are presented, and numerical methods are introduced on a need-to-know basis and in increasing order of difficulty Matlab codes are presented and discussed for a broad...

A wash fluid for drilling into a field

Energy Technology Data Exchange (ETDEWEB)

Belyakov, V M; Badzhurak, R F; Koptelova, Ye K; Rogovoy, V K; Sapozhnikov, N G

1979-01-18

A wash fluid is proposed, used in drilling wells in water and a content of 3-5% by weight starch products. To speed up destruction of the starch products, to the fluid are added amylolytic enzymes in the amount of 0.01-0.1 percent by weight of the starch products' weight. To lower the use of starch products, up to 3% clay can be added to the fluid. The wash fluid is prepared directly at the work site. Dry powder of modified starch is mixed with cold water until a colloidal solution is obtained. Such a wash fluid preserves the required structural-mechanical properties for 3-5 days, which ensures prompt drilling into the waterbearing layer and installation of the filter. Then, during the work process, 5-6 hours before the moment required for lowering the viscosity, to the wash fluid is added the amylolytic enzyme; under its influence, the starch molecules split up, and the viscosity drops sharply. Using this wash fluid enables a reduction in well construction times from the beginning of drilling to the end of development of the water-bearing layer, and a rise in outputs and well service lives by reducing sedimentation of the water-bearing formation and elimination of down times during work required while waiting for destruction of the starch wash fluid under natural conditions.

Hamiltonian closures in fluid models for plasmas

Science.gov (United States)

Tassi, Emanuele

2017-11-01

This article reviews recent activity on the Hamiltonian formulation of fluid models for plasmas in the non-dissipative limit, with emphasis on the relations between the fluid closures adopted for the different models and the Hamiltonian structures. The review focuses on results obtained during the last decade, but a few classical results are also described, in order to illustrate connections with the most recent developments. With the hope of making the review accessible not only to specialists in the field, an introduction to the mathematical tools applied in the Hamiltonian formalism for continuum models is provided. Subsequently, we review the Hamiltonian formulation of models based on the magnetohydrodynamics description, including those based on the adiabatic and double adiabatic closure. It is shown how Dirac's theory of constrained Hamiltonian systems can be applied to impose the incompressibility closure on a magnetohydrodynamic model and how an extended version of barotropic magnetohydrodynamics, accounting for two-fluid effects, is amenable to a Hamiltonian formulation. Hamiltonian reduced fluid models, valid in the presence of a strong magnetic field, are also reviewed. In particular, reduced magnetohydrodynamics and models assuming cold ions and different closures for the electron fluid are discussed. Hamiltonian models relaxing the cold-ion assumption are then introduced. These include models where finite Larmor radius effects are added by means of the gyromap technique, and gyrofluid models. Numerical simulations of Hamiltonian reduced fluid models investigating the phenomenon of magnetic reconnection are illustrated. The last part of the review concerns recent results based on the derivation of closures preserving a Hamiltonian structure, based on the Hamiltonian structure of parent kinetic models. Identification of such closures for fluid models derived from kinetic systems based on the Vlasov and drift-kinetic equations are presented, and

Core-shell particles at fluid interfaces

NARCIS (Netherlands)

Buchcic, C.

2016-01-01

There is a growing interest in the use of particles as stabilizers for foams and emulsions. Applying hard particles for stabilization of fluid interface is referred to as Pickering stabilization. By using hard particles instead of surfactants and polymers, fluid interfaces can be effectively

Technical fluid dynamics. 7. rev. ed.

International Nuclear Information System (INIS)

Becker, E.; Piltz, E.

1993-01-01

An introductory textbook for students of engineering containing the following subjects: Definition and properties of fluids, hydrostatics, Bernoulli's equation, theorem of momentum for steadystate flows, wing lattice and single wing, plane parallel flow of a viscous fluid, pipe flow, boundary layers, gas flows. (orig.) [de

Rotational superradiance in fluid laboratories

CERN Document Server

Cardoso, Vitor; Richartz, Mauricio; Weinfurtner, Silke

2016-01-01

Rotational superradiance has been predicted theoretically decades ago, and is the chief responsible for a number of important effects and phenomenology in black hole physics. However, rotational superradiance has never been observed experimentally. Here, with the aim of probing superradiance in the lab, we investigate the behaviour of sound and surface waves in fluids resting in a circular basin at the center of which a rotating cylinder is placed. We show that with a suitable choice for the material of the cylinder, surface and sound waves are amplified. By confining the superradiant modes near the rotating cylinder, an instability sets in. Our findings are experimentally testable in existing fluid laboratories and hence offer experimental exploration and comparison of dynamical instabilities arising from rapidly rotating boundary layers in astrophysical as well as in fluid dynamical systems.

Edge Fracture in Complex Fluids.

Science.gov (United States)

Hemingway, Ewan J; Kusumaatmaja, Halim; Fielding, Suzanne M

2017-07-14

We study theoretically the edge fracture instability in sheared complex fluids, by means of linear stability analysis and direct nonlinear simulations. We derive an exact analytical expression for the onset of edge fracture in terms of the shear-rate derivative of the fluid's second normal stress difference, the shear-rate derivative of the shear stress, the jump in shear stress across the interface between the fluid and the outside medium (usually air), the surface tension of that interface, and the rheometer gap size. We provide a full mechanistic understanding of the edge fracture instability, carefully validated against our simulations. These findings, which are robust with respect to choice of rheological constitutive model, also suggest a possible route to mitigating edge fracture, potentially allowing experimentalists to achieve and accurately measure flows stronger than hitherto possible.

Magnetic movement of biological fluid droplets

International Nuclear Information System (INIS)

Garcia, Antonio A.; Egatz-Gomez, Ana; Lindsay, Solitaire A.; Dominguez-Garcia, P.; Melle, Sonia; Marquez, Manuel; Rubio, Miguel A.; Picraux, S.T.; Yang, Dongqing; Aella, P.; Hayes, Mark A.; Gust, Devens; Loyprasert, Suchera; Vazquez-Alvarez, Terannie; Wang, Joseph

2007-01-01

Magnetic fields can be used to control the movement of aqueous drops on non-patterned, silicon nanowire superhydrophobic surfaces. Drops of aqueous and biological fluids are controlled by introducing magnetizable carbonyl iron microparticles into the liquid. Key elements of operations such as movement, coalescence, and splitting of water and biological fluid drops, as well as electrochemical measurement of an analyte are demonstrated. Superhydrophobic surfaces were prepared using vapor-liquid-solid (VLS) growth systems followed by coating with a perfluorinated hydrocarbon molecule. Drops were made from aqueous and biological fluid suspensions with magnetizable microparticle concentrations ranging from 0.1 to 10 wt%

Electrodynamics of a Cosmic Dark Fluid

Directory of Open Access Journals (Sweden)

Alexander B. Balakin

2016-06-01

Full Text Available Cosmic Dark Fluid is considered as a non-stationary medium, in which electromagnetic waves propagate, and magneto-electric field structures emerge and evolve. A medium-type representation of the Dark Fluid allows us to involve in its analysis the concepts and mathematical formalism elaborated in the framework of classical covariant electrodynamics of continua, and to distinguish dark analogs of well-known medium-effects, such as optical activity, pyro-electricity, piezo-magnetism, electro- and magneto-striction and dynamo-optical activity. The Dark Fluid is assumed to be formed by a duet of a Dark Matter (a pseudoscalar axionic constituent and Dark Energy (a scalar element; respectively, we distinguish electrodynamic effects induced by these two constituents of the Dark Fluid. The review contains discussions of 10 models, which describe electrodynamic effects induced by Dark Matter and/or Dark Energy. The models are accompanied by examples of exact solutions to the master equations, correspondingly extended; applications are considered for cosmology and space-times with spherical and pp-wave symmetries. In these applications we focused the attention on three main electromagnetic phenomena induced by the Dark Fluid: first, emergence of Longitudinal Magneto-Electric Clusters; second, generation of anomalous electromagnetic responses; third, formation of Dark Epochs in the Universe history.

Generalized Fluid System Simulation Program (GFSSP) - Version 6

Science.gov (United States)

Majumdar, Alok; LeClair, Andre; Moore, Ric; Schallhorn, Paul

2015-01-01

The Generalized Fluid System Simulation Program (GFSSP) is a finite-volume based general-purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjugate heat transfer between solid and fluid, fluid transients, pumps, compressors, flow control valves and external body forces such as gravity and centrifugal. The thermo-fluid system to be analyzed is discretized into nodes, branches, and conductors. The scalar properties such as pressure, temperature, and concentrations are calculated at nodes. Mass flow rates and heat transfer rates are computed in branches and conductors. The graphical user interface allows users to build their models using the 'point, drag, and click' method; the users can also run their models and post-process the results in the same environment. The integrated fluid library supplies thermodynamic and thermo-physical properties of 36 fluids, and 24 different resistance/source options are provided for modeling momentum sources or sinks in the branches. Users can introduce new physics, non-linear and time-dependent boundary conditions through user-subroutine.

A systems approach to theoretical fluid mechanics: Fundamentals

Science.gov (United States)

Anyiwo, J. C.

1978-01-01

A preliminary application of the underlying principles of the investigator's general system theory to the description and analyses of the fluid flow system is presented. An attempt is made to establish practical models, or elements of the general fluid flow system from the point of view of the general system theory fundamental principles. Results obtained are applied to a simple experimental fluid flow system, as test case, with particular emphasis on the understanding of fluid flow instability, transition and turbulence.

Acoustic Streaming and Its Suppression in Inhomogeneous Fluids

DEFF Research Database (Denmark)

Karlsen, Jonas Tobias; Qiu, Wei; Augustsson, Per

2018-01-01

We present a theoretical and experimental study of boundary-driven acoustic streaming in an inhomogeneous fluid with variations in density and compressibility. In a homogeneous fluid this streaming results from dissipation in the boundary layers (Rayleigh streaming). We show...... that in an inhomogeneous fluid, an additional nondissipative force density acts on the fluid to stabilize particular inhomogeneity configurations, which markedly alters and even suppresses the streaming flows. Our theoretical and numerical analysis of the phenomenon is supported by ultrasound experiments performed...

Modeling of Dynamic Fluid Forces in Fast Switching Valves

DEFF Research Database (Denmark)

Roemer, Daniel Beck; Johansen, Per; Pedersen, Henrik Clemmensen

2015-01-01

Switching valves experience opposing fluid forces due to movement of the moving member itself, as the surrounding fluid volume must move to accommodate the movement. This movement-induced fluid force may be divided into three main components; the added mass term, the viscous term and the socalled...... history term. For general valve geometries there are no simple solution to either of these terms. During development and design of such switching valves, it is therefore, common practice to use simple models to describe the opposing fluid forces, neglecting all but the viscous term which is determined...... based on shearing areas and venting channels. For fast acting valves the opposing fluid force may retard the valve performance significantly, if appropriate measures are not taken during the valve design. Unsteady Computational Fluid Dynamics (CFD) simulations are available to simulate the total fluid...

Organosilicon fluid for cooling coal combine motors

Energy Technology Data Exchange (ETDEWEB)

Donets, I K; Dmitrenko, Yu N; Kovalev, Ye B; Sukhanov, V V; Tsingarelli, Ye P

1983-01-01

Results are presented of toxicological evaluation of the polymer organosilicon fluid FM-5.6AP which should be used as the cooling agent of the electric motors of coal combines. It was established that fluid FM-5.6AP belongs to the low-toxic substances that do not have skinresorptive, skin-damaging and cumulative effect, do not have a significant influence on phagocytosis of the coal dust, in depositing in the lungs and elimination. During experimental industrial tests of the motor using the fluid FM-5.6AP, no toxic effect of it on the body was revealed. The possibility is shown of using organosilicon fluid FM-5.6AP for cooling electric motors of coal combines.

Parametric investigation of working fluids for organic Rankine cycle applications

International Nuclear Information System (INIS)

Brown, J. Steven; Brignoli, Riccardo; Quine, Timothy

2015-01-01

This paper investigates working fluids for organic Rankine cycle (ORC) applications with a goal of identifying “ideal” working fluids for five renewable/alternative energy sources. It employs a methodology for screening and comparing with good engineering accuracy the thermodynamic performance potential of ORC operating with working fluids that are not well characterized experimentally or by high-accuracy equations of state. A wide range of “theoretical” working fluids are investigated with the goals to identify potential alternative working fluids and to guide future research and development efforts of working fluids. The “theoretical” working fluids investigated are described in terms of critical state properties, acentric factor, and ideal gas specific heat capacity at constant pressure and are obtained by parametrically varying each of these parameters. The performances of these “theoretical” working fluids are compared to the performances of several “real” working fluids. The study suggests a working fluid's critical temperature and its critical ideal gas molar heat capacity have the largest impact on the cycle efficiency and volumetric work output, with “ideal” working fluids for high efficiency possessing critical temperatures on the order of 100%–150% of the source temperature and possessing intermediate values of critical ideal gas molar heat capacity. - Highlights: • “Ideal” working fluids are investigated for organic Rankine cycles (ORC). • The thermodynamic space of “ideal” working fluids is parametrically investigated. • Five low- and high-temperature ORC applications are investigated. • 1620 “ideal” and several “real” working fluids per application are investigated.

Fluid logic control circuit operates nutator actuator motor

Science.gov (United States)

1966-01-01

Fluid logic control circuit operates a pneumatic nutator actuator motor. It has no moving parts and consists of connected fluid interaction devices. The operation of this circuit demonstrates the ability of fluid interaction devices to operate in a complex combination of series and parallel logic sequence.

Downhole Fluid Analyzer Development

Energy Technology Data Exchange (ETDEWEB)

Bill Turner

2006-11-28

A novel fiber optic downhole fluid analyzer has been developed for operation in production wells. This device will allow real-time determination of the oil, gas and water fractions of fluids from different zones in a multizone or multilateral completion environment. The device uses near infrared spectroscopy and induced fluorescence measurement to unambiguously determine the oil, water and gas concentrations at all but the highest water cuts. The only downhole components of the system are the fiber optic cable and windows. All of the active components--light sources, sensors, detection electronics and software--will be located at the surface, and will be able to operate multiple downhole probes. Laboratory testing has demonstrated that the sensor can accurately determine oil, water and gas fractions with a less than 5 percent standard error. Once installed in an intelligent completion, this sensor will give the operating company timely information about the fluids arising from various zones or multilaterals in a complex completion pattern, allowing informed decisions to be made on controlling production. The research and development tasks are discussed along with a market analysis.

Microfluidics with fluid walls.

Science.gov (United States)

Walsh, Edmond J; Feuerborn, Alexander; Wheeler, James H R; Tan, Ann Na; Durham, William M; Foster, Kevin R; Cook, Peter R

2017-10-10

Microfluidics has great potential, but the complexity of fabricating and operating devices has limited its use. Here we describe a method - Freestyle Fluidics - that overcomes many key limitations. In this method, liquids are confined by fluid (not solid) walls. Aqueous circuits with any 2D shape are printed in seconds on plastic or glass Petri dishes; then, interfacial forces pin liquids to substrates, and overlaying an immiscible liquid prevents evaporation. Confining fluid walls are pliant and resilient; they self-heal when liquids are pipetted through them. We drive flow through a wide range of circuits passively by manipulating surface tension and hydrostatic pressure, and actively using external pumps. Finally, we validate the technology with two challenging applications - triggering an inflammatory response in human cells and chemotaxis in bacterial biofilms. This approach provides a powerful and versatile alternative to traditional microfluidics.The complexity of fabricating and operating microfluidic devices limits their use. Walsh et al. describe a method in which circuits are printed as quickly and simply as writing with a pen, and liquids in them are confined by fluid instead of solid walls.

Dynamics of radiating fluids

International Nuclear Information System (INIS)

Mihalas, D.; Weaver, R.

1982-01-01

The purpose of this paper is to give an overview of the role of radiation in the transport of energy and momentum in a combined matter-radiation fluid. The transport equation for a moving radiating fluid is presented in both a fully Eulerian and a fully Lagrangian formulation, along with conservation equations describing the dynamics of the fluid. Special attention is paid to the problem of deriving equations that are mutually consistent in each frame, and between frames, to 0(v/c). A detailed analysis is made to show that in situations of broad interest, terms that are formally of 0(v/c) actually dominate the solution, demonstrating that it is essential (1) to pay scrupulous attention to the question of the frame dependence in formulating the equations, and (2) to solve the equations to 0(v/c) in quite general circumstances. These points are illustrated in the context of the nonequilibrium radiation diffusion limit, and a sketch of how the Lagrangian equations are to be solved is presented

Partitioned fluid-solid coupling for cardiovascular blood flow: left-ventricular fluid mechanics.

Science.gov (United States)

Krittian, Sebastian; Janoske, Uwe; Oertel, Herbert; Böhlke, Thomas

2010-04-01

We present a 3D code-coupling approach which has been specialized towards cardiovascular blood flow. For the first time, the prescribed geometry movement of the cardiovascular flow model KaHMo (Karlsruhe Heart Model) has been replaced by a myocardial composite model. Deformation is driven by fluid forces and myocardial response, i.e., both its contractile and constitutive behavior. Whereas the arbitrary Lagrangian-Eulerian formulation (ALE) of the Navier-Stokes equations is discretized by finite volumes (FVM), the solid mechanical finite elasticity equations are discretized by a finite element (FEM) approach. Taking advantage of specialized numerical solution strategies for non-matching fluid and solid domain meshes, an iterative data-exchange guarantees the interface equilibrium of the underlying governing equations. The focus of this work is on left-ventricular fluid-structure interaction based on patient-specific magnetic resonance imaging datasets. Multi-physical phenomena are described by temporal visualization and characteristic FSI numbers. The results gained show flow patterns that are in good agreement with previous observations. A deeper understanding of cavity deformation, blood flow, and their vital interaction can help to improve surgical treatment and clinical therapy planning.

Extraperitoneal Fluid Collection due to Chronic Pancreatitis

Directory of Open Access Journals (Sweden)

Takeo Yasuda

2013-08-01

Full Text Available A 39-year-old man was referred to our hospital for the investigation of abdominal fluid collection. He was pointed out to have alcoholic chronic pancreatitis. Laboratory data showed inflammation and slightly elevated serum direct bilirubin and amylase. An abdominal computed tomography demonstrated huge fluid collection, multiple pancreatic pseudocysts and pancreatic calcification. The fluid showed a high level of amylase at 4,490 IU/l. Under the diagnosis of pancreatic ascites, endoscopic pancreatic stent insertion was attempted but was unsuccessful, so surgical treatment (Frey procedure and cystojejunostomy was performed. During the operation, a huge amount of fluid containing bile acid (amylase at 1,474 IU/l and bilirubin at 13.5 mg/dl was found to exist in the extraperitoneal space (over the peritoneum, but no ascites was found. His postoperative course was uneventful and he shows no recurrence of the fluid. Pancreatic ascites is thought to result from the disruption of the main pancreatic duct, the rupture of a pancreatic pseudocyst, or possibly leakage from an unknown site. In our extremely rare case, the pancreatic pseudocyst penetrated into the hepatoduodenal ligament with communication to the common bile duct, and the fluid flowed into the round ligament of the liver and next into the extraperitoneal space.

Four-fluid model of PWR degraded cores

International Nuclear Information System (INIS)

Dearing, J.F.

1985-01-01

This paper describes the new two-dimensional, four-fluid fluid dynamics and heat transfer (FLUIDS) module of the MELPROG code. MELPROG is designed to give an integrated, mechanistic treatment of pressurized water reactor (PWR) core meltdown accidents from accident initiation to vessel melt-through. The code has a modular data storage and transfer structure, with each module providing the others with boundary conditions at each computational time step. Thus the FLUIDS module receives mass and energy source terms from the fuel pin module, the structures module, and the debris bed module, and radiation energy source terms from the radiation module. MELPROG, which models the reactor vessel, is also designed to model the vessel as a component in the TRAC/PF1 networking solution of a PWR reactor coolant system (RCS). The coupling between TRAC and MELPROG is implicit in the fluid dynamics of the reactor coolant (liquid water and steam) allowing an accurate simulation of the coupling between the vessel and the rest of the RCS during an accident. This paper deals specifically with the numerical model of fluid dynamics and heat transfer within the reactor vessel, which allows a much more realistic simulation (with less restrictive assumptions on physical behavior) of the accident than has been possible before

Computer methods for transient fluid-structure analysis of nuclear reactors

International Nuclear Information System (INIS)

Belytschko, T.; Liu, W.K.

1985-01-01

Fluid-structure interaction problems in nuclear engineering are categorized according to the dominant physical phenomena and the appropriate computational methods. Linear fluid models that are considered include acoustic fluids, incompressible fluids undergoing small disturbances, and small amplitude sloshing. Methods available in general-purpose codes for these linear fluid problems are described. For nonlinear fluid problems, the major features of alternative computational treatments are reviewed; some special-purpose and multipurpose computer codes applicable to these problems are then described. For illustration, some examples of nuclear reactor problems that entail coupled fluid-structure analysis are described along with computational results

Lagrange formalism for a system of several fluids interacting electromagnetically; Formalisme lagrangien pour un systeme de plusieurs fluides en interaction electromagnetique

Energy Technology Data Exchange (ETDEWEB)

Vuillemin, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

After giving the Lagrange expression for a conducting fluid in an external electromagnetic field, the author shows that a Lagrange expression exists for describing the evolution of a system of interacting fluids obtained by adding the Lagrange expression of each fluid.to that of the electromagnetic field. By variation are obtained the fluid movement equation coupled to the Maxwell equations. It is shown that the study of small movements around a stationary state can be deduced from the Lagrange equation expanded to the second power order of the perturbation. It is then possible to deduce the normal mode equations and the study the stability by examining the modes which are marginally stable. (author) [French] Apres avoir rappele l'expression, du Lagrangien pour un fluide conducteur dans un champ electromagnetique exterieur, on montre qu'il existe un Lagrangien pour decrire l'evolution d'un systeme de fluides en.interaction que l'on obtient par la superposition du Lagrangien de chaque fluide et du Lagrangien du champ electromagnetique. On obtient par variation, les equations du mouvement des fluides, couplees aux equations de Maxwell. On montre que l'etude des petits mouvements autour d'un etat stationnaire se deduit du Lagrangien developpe au second1 ordre en puissance de la perturbation. On peut alors retrouver les equations des modes normaux et etudier la stabilite en recherchant les modes marginalement stables. (auteur)

Fluid Mechanics of Blood Clot Formation.

Science.gov (United States)

Fogelson, Aaron L; Neeves, Keith B

2015-01-01

Intravascular blood clots form in an environment in which hydrodynamic forces dominate and in which fluid-mediated transport is the primary means of moving material. The clotting system has evolved to exploit fluid dynamic mechanisms and to overcome fluid dynamic challenges to ensure that clots that preserve vascular integrity can form over the wide range of flow conditions found in the circulation. Fluid-mediated interactions between the many large deformable red blood cells and the few small rigid platelets lead to high platelet concentrations near vessel walls where platelets contribute to clotting. Receptor-ligand pairs with diverse kinetic and mechanical characteristics work synergistically to arrest rapidly flowing cells on an injured vessel. Variations in hydrodynamic stresses switch on and off the function of key clotting polymers. Protein transport to, from, and within a developing clot determines whether and how fast it grows. We review ongoing experimental and modeling research to understand these and related phenomena.

Superconfinement tailors fluid flow at microscales.

KAUST Repository

Setu, Siti Aminah

2015-06-15

Understanding fluid dynamics under extreme confinement, where device and intrinsic fluid length scales become comparable, is essential to successfully develop the coming generations of fluidic devices. Here we report measurements of advancing fluid fronts in such a regime, which we dub superconfinement. We find that the strong coupling between contact-line friction and geometric confinement gives rise to a new stability regime where the maximum speed for a stable moving front exhibits a distinctive response to changes in the bounding geometry. Unstable fronts develop into drop-emitting jets controlled by thermal fluctuations. Numerical simulations reveal that the dynamics in superconfined systems is dominated by interfacial forces. Henceforth, we present a theory that quantifies our experiments in terms of the relevant interfacial length scale, which in our system is the intrinsic contact-line slip length. Our findings show that length-scale overlap can be used as a new fluid-control mechanism in strongly confined systems.

Astrophysical fluid dynamics

Science.gov (United States)

Ogilvie, Gordon I.

2016-06-01

> These lecture notes and example problems are based on a course given at the University of Cambridge in Part III of the Mathematical Tripos. Fluid dynamics is involved in a very wide range of astrophysical phenomena, such as the formation and internal dynamics of stars and giant planets, the workings of jets and accretion discs around stars and black holes and the dynamics of the expanding Universe. Effects that can be important in astrophysical fluids include compressibility, self-gravitation and the dynamical influence of the magnetic field that is `frozen in' to a highly conducting plasma. The basic models introduced and applied in this course are Newtonian gas dynamics and magnetohydrodynamics (MHD) for an ideal compressible fluid. The mathematical structure of the governing equations and the associated conservation laws are explored in some detail because of their importance for both analytical and numerical methods of solution, as well as for physical interpretation. Linear and nonlinear waves, including shocks and other discontinuities, are discussed. The spherical blast wave resulting from a supernova, and involving a strong shock, is a classic problem that can be solved analytically. Steady solutions with spherical or axial symmetry reveal the physics of winds and jets from stars and discs. The linearized equations determine the oscillation modes of astrophysical bodies, as well as their stability and their response to tidal forcing.

Ten iterative steps for model development and evaluation applied to Computational Fluid Dynamics for Environmental Fluid Mechanic

NARCIS (Netherlands)

Blocken, B.J.E.; Gualtieri, C.

2012-01-01

Computational Fluid Dynamics (CFD) is increasingly used to study a wide variety of complex Environmental Fluid Mechanics (EFM) processes, such as water flow and turbulent mixing of contaminants in rivers and estuaries and wind flow and air pollution dispersion in urban areas. However, the accuracy

Rheological properties of PHPA polymer support fluids

OpenAIRE

Lam, Carlos; Martin, P J; Jefferis, S A

2015-01-01

Synthetic polymer fluids are becoming a popular replacement for bentonite slurries to support excavations for deep foundation elements. However, the rheological properties of the polymer fluids used in excavation support have not been studied in detail, and there is currently confusion about the choice of mathematical models for this type of fluid. To advance the current state of knowledge, a laboratory study has been performed to investigate the steady-shear viscosity and transient viscoelas...

Statistical mechanics of fluids under internal constraints: Rigorous results for the one-dimensional hard rod fluid

International Nuclear Information System (INIS)

Corti, D.S.; Debenedetti, P.G.

1998-01-01

The rigorous statistical mechanics of metastability requires the imposition of internal constraints that prevent access to regions of phase space corresponding to inhomogeneous states. We derive exactly the Helmholtz energy and equation of state of the one-dimensional hard rod fluid under the influence of an internal constraint that places an upper bound on the distance between nearest-neighbor rods. This type of constraint is relevant to the suppression of boiling in a superheated liquid. We determine the effects of this constraint upon the thermophysical properties and internal structure of the hard rod fluid. By adding an infinitely weak and infinitely long-ranged attractive potential to the hard core, the fluid exhibits a first-order vapor-liquid transition. We determine exactly the equation of state of the one-dimensional superheated liquid and show that it exhibits metastable phase equilibrium. We also derive statistical mechanical relations for the equation of state of a fluid under the action of arbitrary constraints, and show the connection between the statistical mechanics of constrained and unconstrained ensembles. copyright 1998 The American Physical Society

Structural priority approach to fluid-structure interaction problems

International Nuclear Information System (INIS)

Au-Yang, M.K.; Galford, J.E.

1981-01-01

In a large class of dynamic problems occurring in nuclear reactor safety analysis, the forcing function is derived from the fluid enclosed within the structure itself. Since the structural displacement depends on the fluid pressure, which in turn depends on the structural boundaries, a rigorous approach to this class of problems involves simultaneous solution of the coupled fluid mechanics and structural dynamics equations with the structural response and the fluid pressure as unknowns. This paper offers an alternate approach to the foregoing problems. 8 refs

Serious Fun: Using Toys to Demonstrate Fluid Mechanics Principles

Science.gov (United States)

Saviz, Camilla M.; Shakerin, Said

2014-01-01

Many students have owned or seen fluids toys in which two immiscible fluids within a closed container can be tilted to generate waves. These types of inexpensive and readily available toys are fun to play with, but they are also useful for provoking student learning about fluid properties or complex fluid behavior, including drop formation and…

Low-temperature susceptibility of concentrated magnetic fluids

Science.gov (United States)

Pshenichnikov, Alexander F.; Lebedev, Alexander V.

2004-09-01

The initial susceptibility of concentrated magnetic fluids (ferrocolloids) has been experimentally investigated at low temperatures. The results obtained indicate that the interparticle dipole-dipole interactions can increase the susceptibility by several times as compared to the Langevin value. It is shown that good agreement between recent theoretical models and experimental observations can be achieved by introducing a correction for coefficients in the series expansion of susceptibility in powers of density and aggregation parameter. A modified equation for equilibrium susceptibility is offered to sum over corrections made by Kalikmanov (Statistical Physics of Fluids, Springer-Verlag, Berlin, 2001) and by B. Huke and M. Lücke (Phys. Rev. E 67, 051403, 2003). The equation gives good quantitative agreement with the experimental data in the wide range of temperature and magnetic particles concentration. It has been found that in some cases the magnetic fluid solidification occurs at temperature several tens of kelvins higher than the crystallization temperature of the carrier liquid. The solidification temperature of magnetic fluids is independent of particle concentration (i.e., magneto-dipole interparticle interactions) and dependent on the surfactant type and carrier liquid. This finding allows us to suggest that molecular interactions and generation of some large-scale structure from colloidal particles in magnetic fluids are responsible for magnetic fluid solidification. If the magnetic fluid contains the particles with the Brownian relaxation mechanism of the magnetic moment, the solidification manifests itself as the peak on the "susceptibility-temperature" curve. This fact proves the dynamic nature of the observed peak: it arises from blocking the Brownian mechanism of the magnetization relaxation.