Author: Basil N. AntarPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Gas-liquid, Two Phase Flow Dynamics in Low Gravity
Author: Basil N. AntarStudies of Two-Phase Flow Dynamics and Heat Transfer at Reduced Gravity Conditions
Author: Studies of Two-Phase Flow Dynamics and Heat Transfer at Reduced Gravity Conditions
Author: National Aeronautics and Space Administration (NASA)Publisher: Createspace Independent Publishing Platform
ISBN: 9781722817558
Category :
Languages : en
Pages : 44
Book Description
The ability to predict gas-liquid flow patterns is crucial to the design and operation of two-phase flow systems in the microgravity environment. Flow pattern maps have been developed in this study which show the occurrence of flow patterns as a function of gas and liquid superficial velocities as well as tube diameter, liquid viscosity and surface tension. The results have demonstrated that the location of the bubble-slug transition is affected by the tube diameter for air-water systems and by surface tension, suggesting that turbulence-induced bubble fluctuations and coalescence mechanisms play a role in this transition. The location of the slug-annular transition on the flow pattern maps is largely unaffected by tube diameter, liquid viscosity or surface tension in the ranges tested. Void fraction-based transition criteria were developed which separate the flow patterns on the flow pattern maps with reasonable accuracy. Weber number transition criteria also show promise but further work is needed to improve these models. For annular gas-liquid flows of air-water and air- 50 percent glycerine under reduced gravity conditions, the pressure gradient agrees fairly well with a version of the Lockhart-Martinelli correlation but the measured film thickness deviates from published correlations at lower Reynolds numbers. Nusselt numbers, based on a film thickness obtained from standard normal-gravity correlations, follow the relation, Nu = A Re(sup n) Pr(exp l/3), but more experimental data in a reduced gravity environment are needed to increase the confidence in the estimated constants, A and n. In the slug flow regime, experimental pressure gradient does not correlate well with either the Lockhart-Martinelli or a homogeneous formulation, but does correlate nicely with a formulation based on a two-phase Reynolds number. Comparison with ground-based correlations implies that the heat transfer coefficients are lower at reduced gravity than at normal gravity under the same ...
Fundamentals of Low Gravity Fluid Dynamics and Heat Transfer
Author: Basil N. AntarPublisher: CRC Press
ISBN: 1351089080
Category : Technology & Engineering
Languages : en
Pages : 351
Book Description
This book presents the fundamentals of low gravity fluid dynamics and heat transfer. It investigates fluid behavior in low gravity environments such as those found in earth orbiting and space vehicles. The two major fluid phenomena affected by gravity (buoyancy and surface tension) are treated thoroughly from both the theoretical and applications points of view, and limitations of fluid and thermal responses to gravitational fields in space-based settings are clearly delineated. Summaries of all data available from low gravity flight and terrestrial experiments performed to date are also presented.
Two-Phase Gas-Liquid Flow in Pipes with Different Orientations
Author: Afshin J. GhajarPublisher: Springer Nature
ISBN: 3030416267
Category : Science
Languages : en
Pages : 136
Book Description
This book provides design engineers using gas-liquid two-phase flow in different industrial applications the necessary fundamental understanding of the two-phase flow variables. Two-phase flow literature reports a plethora of correlations for determination of flow patterns, void fraction, two- phase pressure drop and non-boiling heat transfer correlations. However, the validity of a majority of these correlations is restricted over a narrow range of two -phase flow conditions. Consequently, it is quite a challenging task for the end user to select an appropriate correlation/model for the type of two-phase flow under consideration. Selection of a correct correlation also requires some fundamental understanding of the two-phase flow physics and the underlying principles/assumptions/limitations associated with these correlations. Thus, it is of significant interest for a design engineer to have knowledge of the flow patterns and their transitions and their influence on two-phase flow variables. To address some of these issues and facilitate selection of appropriate two-phase flow models, this volume presents a succinct review of the flow patterns, void fraction, pressure drop and non-boiling heat transfer phenomenon and recommend some of the well scrutinized modeling techniques.
Fundamentals of Low Gravity Fluid Dynamics and Heat Transfer
Author: Basil N. AntarPublisher: CRC Press
ISBN: 1351080636
Category : Technology & Engineering
Languages : en
Pages : 312
Book Description
This book presents the fundamentals of low gravity fluid dynamics and heat transfer. It investigates fluid behavior in low gravity environments such as those found in earth orbiting and space vehicles. The two major fluid phenomena affected by gravity (buoyancy and surface tension) are treated thoroughly from both the theoretical and applications points of view, and limitations of fluid and thermal responses to gravitational fields in space-based settings are clearly delineated. Summaries of all data available from low gravity flight and terrestrial experiments performed to date are also presented.
Two-Phase Flows
Author: Shih-i PaiPublisher: Springer-Verlag
ISBN: 3322863484
Category : Science
Languages : de
Pages : 373
Book Description
Two-Phase Flow
Author: Cl KleinstreuerPublisher: Routledge
ISBN: 1351406485
Category : Science
Languages : en
Pages : 472
Book Description
This graduate text provides a unified treatment of the fundamental principles of two-phase flow and shows how to apply the principles to a variety of homogeneous mixture as well as separated liquid-liquid, gas-solid, liquid-solid, and gas-liquid flow problems, which may be steady or transient, laminar or turbulent.Each chapter contains several sample problems, which illustrate the outlined theory and provide approaches to find simplified analytic descriptions of complex two-phase flow phenomena.This well-balanced introductory text will be suitable for advanced seniors and graduate students in mechanical, chemical, biomedical, nuclear, environmental and aerospace engineering, as well as in applied mathematics and the physical sciences. It will be a valuable reference for practicing engineers and scientists. A solutions manual is available to qualified instructors.
Two-phase Gas-liquid Flow Dynamics: Part I. Flow Oscillations in Transparent, Parallel, Vertical, Heated Channels. Part Ii. Acoustic Velocity in Two-phase Flow
Author: S. William Gouse (Jr)Publisher:
ISBN:
Category :
Languages : en
Pages : 121
Book Description
A natural and forced convection closed loop with three, parallel, vertical, transparent, heated channels with a constant pressure drop maintained across the heated channels, employing refrigerant 113 as the test fluid, was constructed and operated. Regions of uniform and oscillating flow were mapped for the following range of variables: (a) pressure level at the heated section inlet, 10-20 psig; (b) inlet subcooling to 90F; (c) mass flow rate per test section to 1200 1bm/hr; (d) uniform heat flux to 16,000 BTU/hr-sq ft. The state of the art in the measurement and prediction of the acoustic velocity in one and two-components two-phase mixtures and flows was reviewed and summarized. As the void fraction of a two-phase gas-liquid mixture increases continuously from zero to approximately 60 per cent, the propagation velocity of a pressure wave in the two-phase mixture decreases from its value in the liquid phase to a minimum and begins to rise. At the point where the liquid phase ceases to be continuous there can be a rapid rise in propagation velocity to a value approaching that in the gas phase alone. However, it was observed that in the range of void fractions, from 0.6 to 1.0, there is a range of propagation speeds which depends on the frequency of the propagating signal, the size distribution of discontinuous phase, the nature of the continuous phase, and the strength of the disturbance. (Author).
Microgravity Two-phase Flow and Heat Transfer
Author: Kamiel S. GabrielPublisher: Springer Science & Business Media
ISBN: 1402051433
Category : Technology & Engineering
Languages : en
Pages : 252
Book Description
Multiphase thermal systems have numerous applications in aerospace, heat-exchange, transport of contaminants in environmental systems, and energy transport and conversion systems. A reduced - or microgravity - environment provides an excellent tool for accurate study of the flow without the masking effects of gravity. This book presents for the first time a comprehensive coverage of all aspects of two-phase flow behaviour in the virtual absence of gravity.