Audience Discussion I: Dealing with Condensed Moisture

2009 ◽  
pp. 4-4-2
Author(s):  
RP Tye
Keyword(s):  
Condensed Moisture

Capillary Forces Described by Effective Contact Angle Distributions via Simulations of the Centrifuge Technique

MRS Advances ◽  
2016 ◽  
Vol 1 (31) ◽  
pp. 2237-2245
Author(s):  
Myles Thomas ◽  
Elizabeth Krenek ◽  
Stephen Beaudoin
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Smooth Surface ◽  
Adhesion Force ◽  
Capillary Forces ◽  
Angle Distribution ◽  
Particle Adhesion ◽  
Multiple Factors ◽  
Effective Contact ◽  
Condensed Moisture

ABSTRACTUnderstanding particle adhesion is vital to any industry where particulate systems are involved. There are multiple factors that affect the strength of the adhesion force, including the physical properties of the interacting materials and the system conditions. Surface roughness on the particles and the surfaces to which they adhere, including roughness at the nanoscale, is critically important to the adhesion force. The focus of this work is on the capillary force that dominates the adhesion whenever condensed moisture is present. Theoretical capillary forces were calculated for smooth particles adhered to smooth and rough surfaces. Simulations of the classical centrifuge technique used to describe particle adhesion to surfaces were performed based on these forces. A model was developed to describe the adhesion of the particles to the rough surface in terms of the adhesion to a smooth surface and an ‘effective’ contact angle distribution.

The Influence of Rainfall Humidity on the Moisture Regime of Envelope Structures with Internal Insulation

2017 ◽  
Vol 731 ◽  
pp. 49-54
Author(s):  
Karel Brambora ◽  
Eva Burgetová
Keyword(s):  
Moisture Regime ◽  
Historical Buildings ◽  
Left Behind ◽  
Standard Assessment ◽  
Capillary Attraction ◽  
Condensed Moisture

While the matters of the moisture of external walls of historical buildings it turned out that apart from classical sources of moisture (such as capillary attraction, condensation etc.) there is another source which is often left behind – rainfall humidity which leaks to perimeter walls from the exterior. Whilst the Czech approach of standard assessment works with condensed moisture only, some foreign authors (especially those from Germany) point out a notable influence of rainfall humidity on the moisture regime of the mentioned constructions. Its amount exceeds the amount of rainfall that leaks into the construction due to diffusion by several times. The issue deserves to be examined in more detail, but the use of nanotechnology could help to solve or improve the problem. In some cases it would be possible to apply the suspension with added nanoparticles into the insulated masonry and improve the properties of masonry, which is facing to rainwater

Numerical modeling of the formation and transport of condensed moisture in the lower pool of a hydroproject during the operation of spring-board spillways

2007 ◽  
Vol 41 (5) ◽  
pp. 255-264 ◽  
Author(s):  
V. N. Koterov ◽  
B. V. Arkhipov ◽  
V. V. Belikov ◽  
V. V. Solbakov ◽  
V. E. Fedosov
Keyword(s):  
Numerical Modeling ◽  
Lower Pool ◽  
Condensed Moisture

Calibrated, late Quaternary age indices using clast rubification and soil development on alluvial surfaces in Pilot Knob Valley, Mojave Desert, southeastern California

2003 ◽  
Vol 60 (3) ◽  
pp. 377-393 ◽  
Author(s):  
John G. Helms ◽  
Sally F. McGill ◽  
Thomas K. Rockwell
Keyword(s):  
Mojave Desert ◽  
Late Quaternary ◽  
Rapid Development ◽  
Slip Rate ◽  
Soil Development ◽  
Alluvial Fan ◽  
Strongly Correlated ◽  
Absolute Age ◽  
Lateral Offset ◽  
Condensed Moisture

AbstractThe orange coating (varnish) that forms on the undersides (ventral sides) of clasts in desert pavements constitutes a potential relative-age indicator. Using Munsell color notation, we semiquantified the color of the orange, ventral varnish on the undersides of clasts from 15 different alluvial fan and terrace surfaces of various ages ranging from less than 500 to about 25,000 yr. All of the surfaces studied are located along the central portion of the left-lateral Garlock fault, in the Mojave Desert of southern California. The amount of left-lateral offset may be used to determine the relative ages of the surfaces. The previously published slip rate of the fault may also be used to estimate the absolute age of each surface. The color of the ventral varnish is strongly correlated with surface age and appears to be a more reliable age-indicator than the percentage coverage of dorsal varnish. Soil development indices also were not as strongly correlated with age, as were the colors of the ventral varnish. In particular, rubification appears to be more useful than soils for distinguishing relative ages among Holocene surfaces. Humidity sensors indicated that the undersides of clasts condensed moisture nightly for a period of several days to over a week after each rain. These frequent wet-dry cycles may be responsible for the rapid development of clast rubification on Holocene surfaces.

scholarly journals A COMPARISON BETWEEN EXPERIENTIAL AND ECMWF REANALYZED CONDENSED MOISTURE PROFILE OVER THE NORTHEASTERN SPHERE

2019 ◽  
Vol XLII-3/W9 ◽  
pp. 177-180
Author(s):  
X. Z. Wang ◽  
B. H. Hu ◽  
J. Wang ◽  
H. Huang ◽  
W. J. Zhang ◽  
...  
Keyword(s):  
Arctic Region ◽  
General Information ◽  
The Arctic ◽  
Cloud Base ◽  
Large Temperature ◽  
Height Distribution ◽  
Liquid Water Path ◽  
Moisture Profile ◽  
Warm Cloud ◽  
Condensed Moisture

Abstract. Base on January and July 4-times daily ECMWF Interim data from 2009 to 2018 over the Northeast Sphere (0–180E,0–90N), the condensed moisture profile of experiential methods and that of ECMWF analysis are compared. The result shows that, the meridional-height distribution of mean cloud condensed moisture has a maximum slab spreading near ground in the Arctic region in July, and the maximum takes a circular shape at 700 hPa above 30N latitude in January. The distribution feature unlike the universal profile, it distributes in a single or double peak function manner, instead of a constant value. The quick decreasing level height and thickness varies with latitude, especially in January. The second experiential profile concerning warm cloud assumes air parcel lifting adiabatically, the liquid water path (LWP) is compared for general information. The result shows that the experiential LWP is much larger than that of the reanalysis by 1 to 2 order, decreasing with latitudes. The possible reason of LWP difference is from the critic water content value of cloud boundary identification. If the value is small, the thickness of warm cloud will be large, temperature and pressure at the cloud base are both large too, results in a larger LWP. These results will enrich the knowledge of the condensed moisture characteristics of ECMWF reanalysis and the experiential moisture profile methods.

scholarly journals РОЗРОБКА ВИСОКОЕФЕКТИВНОЇ СУДНОВОЇ СИСТЕМИ ОЧИЩЕННЯ ПОВІТРЯ ВІД КРАПЛИННОЇ ВОЛОГИ

2018 ◽  
pp. 42-46
Author(s):  
Анатолій Павлович Шевцов ◽  
Сергій Сергійович Рижков
Keyword(s):  
Power Plants ◽  
High Efficiency ◽  
Reverse Flow ◽  
Surface Profile ◽  
Working Fluid ◽  
Efficient Design ◽  
Air Cleaning ◽  
Wide Range ◽  
Design Solutions ◽  
Condensed Moisture

It is investigated one of the directions of increasing the technical, economic and environmental characteristics of engines and power plants by air cleaning as a working fluid of condensed moisture. Prospective methods of aerosol medium separation with the help of gradient intensification of transfer processes in boundary layers of multifunctional surfaces are also investigated. Multifunctional surfaces include surfaces with a coefficient of compactness more than 2000 m2/m3, characterized by improved heat exchange and separating properties. A characteristic feature of the developed separating profiles is the combination of a waveform part with flat input and output elements. In the assembly, the separating profiles form the curved channels with a number of successive confuser and diffuser elements. In diffusor elements, there are separating zones with the gas reverse flow. The liquid film resulting from the droplets deposition, falling into these zones, is influenced by the vortices effect that counteracts the film motion in the direction of the main flow and facilitates its flow under the action of gravity. The investigations of gas dynamics and deposition coefficients of the separation profile were performed. The coefficient of droplets deposition for flow rates of 5, 10, 15, 20 m/s in separating profiles with a radius of 5, 10, 15, 20, 25 mm was calculated. It was determined that vortex zones provide full removal of captured water from the smooth surface profile up to the airspeed of 5 m/s. Excess of this speed leads to the removal of part of the water from the vortex zones. Drainage elements are provided for preventing secondary flooding of the flow in flat sections of the separation profile. Design solutions and a generalized scheme of the ship system of air cleaning of condensed moisture for the air flow from 20 to 2000 m3/h were developed. The introduction of filters based on gradient technologies will increase the reliability, the life of the marine power equipment and its elements. This will contribute to the creation of high-efficiency energy-saving technologies and efficient design solutions for a wide range of gradient marine power plant separators.

Development of Highly Efficient Nuclear HP Steam Turbines Using Physics Based Moisture Loss Models

2007 ◽  
Author(s):  
T. Guo ◽  
W. J. Sumner ◽  
D. C. Hofer
Keyword(s):  
Design Methodology ◽  
Industrial Applications ◽  
Moisture Loss ◽  
Steam Turbines ◽  
Wet Steam ◽  
Path Design ◽  
Loss Models ◽  
Condensed Moisture ◽  
Insight Into ◽  
Loss Mechanisms

Turbines operating under wet steam conditions experience efficiency losses caused by the presence of moisture. A full understanding of these loss mechanisms is required for an accurate prediction of turbine performance. However, due to the extremely complicated nature of the wet steam flow, full numerical simulations are time consuming and expensive and have limited value for the turbine designers. The traditional empirical approach, though simple, generally offers no insight into the moisture loss mechanisms. As a result, little guidance is provided for design improvements. This paper presents a physics-based moisture loss prediction system that has been developed specifically for industrial applications. Three main categories of moisture losses are considered: homogeneous nucleation, thermodynamic (supersaturation) loss and mechanical loss. Two new correlations have been developed that provide a quick means for determining the Wilson Point location, resulting equilibrium moisture deficit and average size and number of the condensed moisture (fog). The thermodynamic losses produced by the non-equilibrium expansion of the wet steam beyond the Wilson Point are modeled using Young’s semi-analytical approach [23]. The mechanical moisture losses are modeled using the myriad of loss models available from the public domain. The combination of this new moisture loss model with existing steam path design tools has greatly improved our understanding of the moisture loss that occurs in wet steam expansions. In particular, it has provided significant insight into flow path design optimization for nuclear high pressure (HP) turbines. As a result, a new design methodology, Nuclear HP Dense Pack™, has been developed for the nuclear HP turbines. Preliminary results have shown this new design methodology has the capability of improving the section efficiency of existing nuclear HP steam turbines by 2-4% points.

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