Free-surface turbulence and air-water gas exchange

by Sean Patrick McKenna

Publisher: Woods Hole Oceanographic Institution in Woods Hole, Mass

Written in English
Published: Pages: 312 Downloads: 465
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Subjects:

  • Turbulence.,
  • Water waves.,
  • Surface waves.,
  • Gas dynamics.

Edition Notes

Statementby Sean Patrick McKenna.
SeriesMIT/WHOI -- 00-29., MIT/WHOI (Series) -- 2000-29.
ContributionsMassachusetts Institute of Technology., Woods Hole Oceanographic Institution.
The Physical Object
Pagination312 p. :
Number of Pages312
ID Numbers
Open LibraryOL16012497M

There are several theories linking gas exchange to turbulence, but the eddy cell model introduced by Lamont and Scott, which parameterizes k in terms of the surface dissipation rate of turbulent kinetic energy, ε, has recently been shown to be one of the most successful [e.g., Zappa et al., ; Tokoro et al., ; Vachon et al., ]. The Cited by:   The thermal signature of a low Reynolds number turbulent jet impacting a free surface was investigated experimentally. Three Reynolds numbers (, , and ) were investigated for a configuration in which the jet nozzle diameter and the depth of the jet beneath the free surface were fixed. A high resolution infrared detector was used to collect thermal imagery of the surface Cited by: 7. Level Courses. CEE Professional Issues and Design Prerequisite: Senior standing. (4 credits) Multidisciplinary team design experience including consideration of codes, regulations, alternate solutions, economic factors, sustainability, constructability, reliability and aesthetics in the solution of a civil or environmental engineering problem. Modification of turbulence at the air‒sea interface due to the presence of surfactants and implications for gas I: Laboratory experiment 95% conf. level 10 -1 10 0 10 1Cited by: 6.

Iso-contours of gas volume fraction Bubble column example - ASM • 3D modeling of dynamic behavior of an air-water churn turbulent bubble-column using the ASM model. • This model solves only one momentum equation for the gas-liquid mixture. • Constant bubble size is Size: KB.   Would a multi-phase approch or Lagrangian particle tracking with models for Particle evaporation/ablation with latent heat exchange. The gas comes under high pressure, the pipes breaks and gas is leaking out into the water and is colded of due to sudden pressure drop, but continue to flow though the water until the free surface and further away. The air–water two-phase flow on stepped spillways behind X-shaped flaring gate piers under very high discharge was numerically simulated using the commercial CFD code FLOW-3D ®. In doing so, the 3-D Reynolds-averaged Navier–Stokes equations were solved, including the RNG k-ε turbulence model and a VOF method, to capture the free by: 1. the interfacial momentum exchange and also the turbulence parameters had to be modelled correctly. Without any special treatment of the free surface, the high velocity gradients at the free surface, especially in the gaseous phase, generate too high turbulence throughout the two-phase flow when using the differential eddy.

() On the effect of different flux limiters on the performance of an engine gas exchange gas-dynamic model. International Journal of Mechanical Sciences , () A dissipation-free numerical method to solve one-dimensional hyperbolic flow by: If the distance from point 2 to the free surface is h as shown in Fig. , so that p2 ¼ rgh, we see that h¼. O2 r22 2g. ðÞ. which is a parabola. The free surface is a paraboloid of. A. Atmane and J. George, “Gas Flux Measurements and modelling below an air-water inreface”, Selected Papers of the 3rd Int. Symposium on Air-Water Gas .   2. A given mass of liquid occupies a given volume and will occupy the container it is in and form a free surface (if the container is of a larger volume). A gas has no fixed volume, it changes volume to expand to fill the containing vessel. It will completely fill the vessel so no free surface is formed.

Free-surface turbulence and air-water gas exchange by Sean Patrick McKenna Download PDF EPUB FB2

Free-surface turbulence and air-water gas exchange / was used to measure the two-dimensional free-surface flow field. Bulk turbulence was found unable to provide a unique relationship for the Author: Sean P. Mckenna. Free-surface turbulence and air-water gas exchange JavaScript is disabled for your browser.

Some features of this site may not work without it. Free-surface turbulence and air-water gas exchange. Download. Ocean Engineering., Woods Hole Oceanographic Institution., GCM, Turbulence, Water waves, Surface waves, Gas dynamics, Free-surface turbulence and air-water gas exchange book Cited by: It is useful to summarize the key aspects of our current understanding of free-surface turbulence and air–water gas exchange in terms of conceptual models, simulations, theory, and observations.

Conceptualizations of the effects of surface films on free-surface turbulence have been suggested by Davies [9], Davies and Rideal [10] and Hunt [19].Cited by: for a study of the mechanisms of air-water gas transfer.

Purposefully Injected Tr acers Using natural tracers to measure air-sea gas exchange rates often in volves two. Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume The transfer of gases across the air-water interface has received much attention over the past two decades, particularly in light of increased societal interest in the exchange of greenhouse gases and pollutants between natural water bodies and the atmosphere.

Measurement uncertainty in gas exchange coefficients / J.S. Gulliver [and others] --Measurements of free surface turbulence / Free-surface turbulence and air-water gas exchange book J.

Orlins and John S. Gulliver --Gas transfer across a zero-shear surface: a local approach / Mohamed A. Atmane and Jacques George --Atmosphere-ocean gas exchange due to bubbles generated by wind wave breaking. Abstract.

The effects of impinging raindrops on both turbulence below the airwater interface and CO 2 transfer across the air-water interface are discussed using laboratory measurements by Takagaki and Komori [].The measurements of CO 2 absorption rate and turbulence quantities in an open-channel flow show that impinging raindrops enhance both turbulent mixing near the free surface on the Cited by: 5.

Abstract. Transport processes at gas-liquid interfaces play a central role in many industrial and environmental systems. For example, such processes at the air-water interface impact evaporation of water from reservoirs, control of regional climate, evasion of carbon in tropical river systems, and the aeration of hypoxic water, to name a by: Visualization of 2-D Divergence on the Free Surface and its Relation to Gas Transfer.- The Air-Water Interface: Turbulence and Scalar Exchange.- Turbulence Generation in the Wind-Driven Subsurface Water Flow.- Defining the Enhancement of Air-Water Interfacial Oxygen Exchange Rate due to Wind-Forced Microscale Waves.-Price: $   Free-surface turbulence and air-water gas exchange  McKenna, Sean P.

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, ) This thesis investigates the physical mechanisms of air-water gas transfer through direct measurements of turbulence at the air--water interface.

The impact of different gas exchange formulations and wind speed products on global air-sea CO₂ fluxes / Rik Wanninkhof --Turbulent gas flux measurements near the air-water interface in a grid-stirred tank / Herlina and Gerhard H. Jirka --Quantitative imaging of CO₂ transfer at an unsheared free surface / Evan A.

Variano, Edwin A. Cowen. Therefore, in this study, based on the fundamental idea that the surface divergence controls the air–water gas transfer and is scaled by the Taylor microscale, as shown in Eq., we examine the relation between the air–water gas transfer and lengthscales of free-surface turbulence using PIV and LIF techniques.

Experimental procedureCited by: Predictions of our future climate vary greatly, with detailed forecasts still subject to debate.

One key uncertainty is caused by the lack of our present knowledge of transport processes in the air-water interface, which poses the main transfer resistance between the oceans and atmosphere.

Modeling and predictions of our global climate can only be improved by gaining a more complete. McGillis, W. R., J. Dacey, J. Ware, D.

Ho, J. Bent, W. Asher, C.J. Zappa, P. Raymond, R. Wanninkhof, and S. Komori, Air-water flux reconciliation. Cambridge Core - Civil and Geotechnical Engineering - Introduction to Chemical Transport in the Environment - by John S.

Gulliver Please note, due to essential maintenance online purchasing will be unavailable between and (GMT) on 23rd November Cited by: Hubert Chanson is the author of several books: "Hydraulic Design of Stepped Cascades, Channels, Weirs and Spillways" (Pergamon, ), "Air Bubble Entrainment in Free-Surface Turbulent Shear Flows" (Academic Press, ), "The Hydraulics of Open Channel Flow: An Introduction" (Butterworth-Heinemann, 1st edition2nd editon ), "The.

size. The measurement of air-water interface area is a function of void fraction, velocity, and bubble sizes. For any bubble shape, bubble size distribution and chord length distribution, the specific air-water interface area a defined as the air-water interface area per unit volume of air and water may be derived from continuity: a = 4*F/V.

This book develops an analysis of the air entrainment processes in free-surface flows. These flows are investigated as homogeneous mixtures with variable density.

Several types of air-water free-surface flows are studied: plunging jet flows, open channel flows, and turbulent water jets discharging into : Elsevier Science. Experiments on turbulence beneath a free surface in a stationary field generated by a Crump weir: turbulence structure ciency of turbulence exchange (of momentum, thermal energy, chemical components) with respect to molecular interface in a cocurrent current air–water flow, with the aimCited by: This "Cited by" count includes citations to the following articles in Scholar.

The ones marked * may be different from the article in the profile. A LABORATORY TECHNIQUE FOR INVESTIGATING THE RELATIONSHIP BETWEEN GAS TRANSFER AND FLUID TURBULENCE T. Dickey, B. Hartman, D. Hammond, E. Hurst University of Southern California A technique has been developed to simultaneously measure fluid turbulence and the exchange rate of gases across the air-water interface of a tank under controlled.

The transfer across the surface of environmental waters is of interest as an important phase in the geophysical and natural biochemical cycles of numer­ ous substances; indeed it governs the transition, one way or the other, be­ tween the dissolved state in the water and the gaseous state in the.

Predictions of our future climate vary greatly, with detailed forecasts still subject to debate. One key uncertainty is caused by the lack of our present knowledge of transport processes in the air-water interface, which poses the main transfer resistance between the oceans and atmosphere.

Modeling. A free surface may be deformed by fluid motions; such deformation may lead to surface roughness, breakup, or disintegration. This paper describes the wide range of free-surface deformations that occur when there is turbulence at the surface, and focuses on turbulence in the denser, liquid, medium.

The Air–Water Interface: Turbulence and Scalar Exchange (S Banerjee & S Maclntyre) Internal Wave Fields Analyzed by Imaging Velocimetry (J Grue) Wave Breaking, Surface Motion, Surf Zone, Air–Sea Interaction and Wind Waves; PIV Methods, Boundary Layer Flows and Turbulence; Breakwaters and Internal Waves.

Modeling Turbulent Entrainment of Air at a Free Surface. C.W. Hirt 5/24/ Flow Science, Inc. Overview In free-surface flows the turbulence in the liquid may be sufficient to disturb the surface to the point of entraining air into the flow. This process is important, for example, in. "Vive la Revolution!" was the theme of the Twenty-Third Symposium on Naval Hydrodynamics held in Val de Reuil, France, from Septemberas more than experts in ship design, construction, and operation came together to exchange naval research developments.

where k is the gas transfer velocity, C s is the oxygen concentration at the equilibrium state, and C b is the oxygen concentration in the liquid. When gas solubility in water is low, as is the case for oxygen, the gas transfer at the air–water interface is defined by the liquid-side gas transfer velocity k with C s estimated by Henry’s law.

The gas transfer velocity has been theoretically Cited by: 1. Modelling of stratified two phase flows using an interfacial area density model T. Höhne & C. Vallée Forschungszentrum Dresden-Rossendorf e.V., Dresden, Germany Abstract Stratified two-phase flow regimes can occur in chemical plants, nuclear reactors and oil pipelines.

A relevant problem is the development of wavy stratified flows. In fluid dynamics, wind waves, or wind-generated waves, are water surface waves that occur on the free surface of bodies of result from the wind blowing over an area of fluid surface. Waves in the oceans can travel hundreds of miles before reaching land.

Wind waves on Earth range in size from small ripples, to waves over ft (30 m) high. atmosphere and inland free surface waters. The chapter by C. Gualtieri and G. Pulci Doria deals with gas-transfer at an unsheared free surface, which can have significant impacts on water quality in aquatic systems.

First, the effects of the properties of the gas being transferred and of turbulence on gas-transfer rate are Size: 4MB.air/water flows, the HAWAC (Horizontal Air/Water Channel) was built. The channel allows in particular the study of air/water slug flow under atmospheric pressure.

Parallel to the experiments, CFD calculations were carried out. The two-fluid model was applied with a special turbulence damping procedure at the free surface. An.As with most high-velocity free-surface flows, stepped spillway flows become self-aerated when the drop height exceeds a critical value.

Due to the step-induced macro-roughness, the flow field becomes more turbulent than on a similar smooth-invert chute. For this reason, cascades are oftentimes used as re-aeration structures in wastewater by: 1.