A Study of Ice-Formation Phenomena on Freezing of Flowing Water in a Pipe

1987 ◽  
Vol 109 (4) ◽  
pp. 965-970 ◽  
Author(s):  
T. Hirata ◽  
H. Matsuzawa
Keyword(s):  
Freezing Temperature ◽  
Ice Formation ◽  
Freezing Process ◽  
Ice Thickness ◽  
Flow Transition ◽  
Water Pipe ◽  
Temperature Ratio ◽  
Smooth Change ◽  
Ice Water ◽  
Ice Shapes

Ice-formation phenomena in a water pipe whose wall is kept at a uniform temperature lower than the freezing temperature of water are examined under the conditions of an unstable ice-water interface. The onset conditions for a step or smooth change in ice thickness occurring with flow transition from laminar to turbulent are found to be correlated with ice thickness at the contraction region of the ice band and are expressed as a function of a pipe Reynolds number ReD, and a cooling temperature ratio θ. It is shown that the transient freezing process depends strongly on flow as well as temperature conditions and that the typical ice shapes at steady-state conditions can be classified on a θ-ReD coordinate system.

Summer–winter transitions in Antarctic ponds I: The physical environment

2011 ◽  
Vol 23 (3) ◽  
pp. 235-242 ◽  
Author(s):  
Ian Hawes ◽  
Karl Safi ◽  
Brian Sorrell ◽  
Jenny Webster-Brown ◽  
David Arscott
Keyword(s):  
Physical Environment ◽  
Average Rate ◽  
Growth Period ◽  
Ice Formation ◽  
Freezing Process ◽  
Ice Thickness ◽  
Ice Shelf ◽  
Continental Antarctica ◽  
The Antarctic ◽  
Summer Growth

AbstractMeltwater ponds are one of the most widespread aquatic habitats in ice-free areas of continental Antarctica. While most studies of such systems occur during the Antarctic summer, here we report on ice formation and water column attributes in four meltwater ponds on the McMurdo Ice Shelf during autumn, when they went from ice-free to > 80 cm thickness of ice. Ice thickness grew at an average rate of 1.5 cm d-1 in all ponds and as ice formed, salts and gases were excluded. This resulted in conductivity rising from 3–5 to > 60 mS cm-1 and contributed to the ebullition of gases. Incorporation of gas bubbles in the ice resulted in a high albedo and under-ice irradiance declined faster than incident, the former falling below 1 W m-2 (daily average) by early April. After two months of ice formation, only 0–15% of the volume of each pond was still liquid, although this represented 5–35% of the pond sediment area, where much of the biological activity was concentrated. We suggest that the stresses that the freezing process imposes may be as important to structuring the biotic communities as those during the more benign summer growth period.

scholarly journals Research on the Migration of the Total Manganese during the Process of Water Icing

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1626 ◽  
Author(s):  
Yan Zhang ◽  
Yuanqing Tang ◽  
Aixin Yu ◽  
Wanli Zhao ◽  
Yucan Liu
Keyword(s):  
Lower Layer ◽  
Water System ◽  
Middle Layer ◽  
Freezing Temperature ◽  
Experimental Methods ◽  
Average Concentration ◽  
Laboratory Simulation ◽  
Ice Thickness ◽  
Ice Water ◽  
Migration Law

Our research focused on the migration law of the total manganese (TMn) during the process of water icing. We utilized two experimental methods: (1) natural icing and (2) simulated icing. While using laboratory simulation, we explored the effects of ice thickness, freezing temperature, and initial concentrations on the migration of TMn in the ice-water system. The distribution coefficient “K” (the ratio of the average concentration of TMn in the ice body to the average concentration of TMn in the under-ice water body) was used to characterize it. The results indicated that TMn continuously migrated from ice to under-ice water during the process of water icing. The concentration of TMn in the ice was the upper layer < middle layer < lower layer, and K decreases as the ice thickness, freezing temperature, and initial concentration increased. We explained the migration of TMn during the process of water icing from the perspective of crystallography. Our research can arouse other researcher’s attention towards the change of TMn concentration in lakes in high latitudes during the icebound period.

scholarly journals Migration Law of Atrazine During Freezing of Water

2021 ◽  
Author(s):  
Yan Zhang ◽  
Wanli Zhao ◽  
Aixin Yu ◽  
Yucan Liu ◽  
Fangyun Ren ◽  
...  
Keyword(s):  
Distribution Coefficient ◽  
High Latitude ◽  
Freezing Temperature ◽  
Freezing Process ◽  
Ice Thickness ◽  
Migration Ability ◽  
Initial Concentration ◽  
Atrazine Concentration ◽  
Freezing Period ◽  
Migration Law

Abstract To explore the migration law of atrazine during the freezing process, an indoor simulated freezing experiment was carried out. The distribution coefficient (K) was used to characterize the migration ability of atrazine and explore the effects of freezing thickness, freezing temperature, and initial concentration on the migration of atrazine between ice and water. The research results showed that the concentration relationship between the ice and water phases was: ice < water before freezing < water under the ice. This indicates that atrazine migrated to the water under the ice during the freezing process in our experiment. The K value decreased as the ice thickness, freezing temperature, and initial concentration increased; thus, the greater the ice thickness, the higher the freezing temperature, the greater the initial atrazine concentration, and the greater the ability of atrazine to migrate to the water under the ice. This study provides a reference for managing natural waterbodies in high-latitude and high-altitude environments during the freezing period.

scholarly journals Tabular Icebergs: Implication from Geophysical Studies of Ice Shelves

1980 ◽  
Vol 1 ◽  
pp. 55-55
Author(s):  
Sion Shabtaie ◽  
Charles R. Bentley
Keyword(s):  
Mass Balance ◽  
Sea Water ◽  
Ice Thickness ◽  
Ice Shelf ◽  
Frictional Drag ◽  
Ice Shelves ◽  
Ross Ice Shelf ◽  
Rift Zones ◽  
Different Characteristics ◽  
Ice Water

Recent geophysical and glaciological investigations of the Ross Ice Shelf have revealed many complexities in the ice shelf that can be important factors in iceberg structure. The presence of rift zones, surface and bottom crevasses, corrugations, ridges and troughs, and other features could substantially modify the hydraulics of iceberg towing and lead to disintegration of the berg in the course of transport.The relationships between the elevation above sea-level and total ice thickness for three ice shelves (Ross, Brunt, and McMurdo) are given; from them, expressions for the thickness/freeboard ratios of tabular icebergs calved from these ice shelves are obtained. The relationships obtained from the measured values of surface elevation and ice thickness are in agreement with models derived assuming hydrostatic equilibrium.Areas of brine infiltration into the Ross Ice Shelf have been mapped. Examples of radar profiles in these zones are shown. Absorption from the brine layers results in a poor or absent bottom echo. It is probable that little saline ice exists at the bottom of the Ross Ice Shelf front due to a rapid bottom melting near the ice front, and that the thickness of the saline ice at the bottom of icebergs calving from the Ross Ice Shelf is no more than a few meters, if there is any at all.We have observed many rift zones on the ice shelf by airborne radar techniques, and at one site the bottom and surface topographies of (buried) rift zones have been delineated. These rift zones play an obvious role in iceberg formation and may also affect the dynamics of iceberg transport. Bottom crevasses with different shapes, sizes, and spacings are abundant in ice shelves; probably some are filled with saline ice and others with unfrozen sea-water. Existence of these bottom crevasses could lead to a rapid disintegration of icebergs in the course of transport, as well as increasing the frictional drag at the ice-water boundary.Radar profiles of the ice-shelf barrier at four sites in flow bands of very different characteristics are shown. In some places rifting upstream from the barrier shows regular spacings, suggesting a periodic calving. Differential bottom melting near the barrier causes the icebergs to have an uneven surface and bottom (i.e. dome-shaped).Electrical resistivity soundings on the ice shelf can be applied to estimate the temperature-depth function, and from that the basal mass-balance rate. With some modifications, the technique may also be applied to estimating the basal mass-balance rates of tabular icebergs.

scholarly journals Experimental Study on Freeze-Thaw Cycle Duration of Saturated Tuff

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Man Huang ◽  
Bin Tang ◽  
Jianliang Jiang ◽  
Renqiu Guan ◽  
Huajun Wang
Keyword(s):  
Phase Transition ◽  
Power Function ◽  
Melting Process ◽  
Freezing Process ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Initial Melting ◽  
Time Required ◽  
Ice Water

The freeze-thaw duration is one of the important factors affecting the change of rock properties. However, this factor has not formed a unified standard in the freeze-thaw cycle test. This study uses saturated tuff samples taken from eastern Zhejiang, China, as research objects to explore the change law of the time required for the rock to reach a full freeze-thaw cycle. Measured results show that the total duration of the freeze-thaw cycle presents an increasing power function with the increase in the number of freeze-thaw cycles. The freezing process is divided into three phases: initial freezing, water-ice phase transition, and deep freezing. The melting process is also divided into three phases: initial melting, ice-water phase transition, and deep melting. The time required for the ice-water phase change stage of the melting process does not change with the increase in the number of freeze-thaw cycles, while the other stages increase as a power function. The proportion of duration of each stage in the freezing process does not change with the increase in the number of cycles. By contrast, the duration proportion of the initial melting phase in the melting process decreases, and the deep melting phase increases. Experimental results of the freeze-thaw cycles of tuff demonstrate that the freeze-thaw duration of the freeze-thaw cycles within 40 times can be set to 9 h. The freezing and melting processes are 6 and 3 h, respectively.

scholarly journals Tabular Icebergs: Implications from Geophysical Studies of Ice Shelves

1982 ◽  
Vol 28 (100) ◽  
pp. 413-430 ◽  
Author(s):  
Sion Shabtaie ◽  
Charles R. Bentley
Keyword(s):  
Mass Balance ◽  
Sea Water ◽  
Ice Thickness ◽  
Ice Shelf ◽  
Frictional Drag ◽  
Ice Shelves ◽  
Ross Ice Shelf ◽  
Rift Zones ◽  
Different Characteristics ◽  
Ice Water

AbstractRecent geophysical and glaciological investigations of the Ross Ice Shelf have revealed many complexities in the ice shelf that can be important factors in iceberg structure. The presence of rift zones, surface and bottom crevasses, corrugations, ridge/troughs, and other features could substantially modify the hydraulics of iceberg towing and lead to disintegration in the course of transport.The relationships between the elevation above sea-level and total ice thickness for three ice shelves (Ross, Brunt, and McMurdo) are given; from them, expressions for the thickness/freeboard ratios of tabular icebergs calved from these ice shelves are obtained. The relationships obtained from the measured values of surface elevation and ice thickness are in agreement with models derived assuming hydrostatic equilibrium.Areas of brine infiltration into the Ross Ice Shelf have been mapped. Examples of radar profiles in these zones are shown. Absorption from the brine layers results in a poor or absent bottom echo. It is probable that little saline ice exists at the bottom of the Ross Ice Shelf front due to a rapid bottom melting near the ice front, and that the thickness of the saline ice at the bottom of icebergs calving from the Ross Ice Shelf is no more than a few meters, if there is any at all.We have observed many rift zones on the ice shelf by airborne radar techniques, and at one site the bottom and surface topographies of (buried) rift zones have been delineated. These rift zones play an obvious role in iceberg formation and may also affect the dynamics of iceberg transport. Bottom crevasses with different shapes, sizes, and spacings are abundant in ice shelves; probably some are filled with saline ice and others with unfrozen sea-water. Existence of these bottom crevasses could lead to a rapid disintegration of icebergs in the course of transport, as well as increasing the frictional drag at the ice-water boundary.Radar profiles of the ice shelf front at four sites in flow bands of very different characteristics are shown. In some places rifting up-stream from the front shows regular spacings, suggesting a periodic calving. Differential bottom melting near the front causes the icebergs to have an uneven surface and bottom (i.e. dome shaped).Electrical resistivity soundings on the ice shelf can be applied to estimate the temperature-depth function, and from that the basal mass-balance rate. With some modifications, the technique may also be applied to estimating the basal mass balance rates of tabular icebergs.

Effect of Particle Size on the Lamellar Pore Microstructure of Porous Al2O3 Ceramics Fabricated by the Unidirectional Freezing

2012 ◽  
Vol 184-185 ◽  
pp. 818-825 ◽  
Author(s):  
Xiao Yong Zhang ◽  
Yan Zhang ◽  
Dou Zhang
Keyword(s):  
Freezing Temperature ◽  
Porous Ceramics ◽  
Solid Loading ◽  
Freezing Process ◽  
Pore Channel ◽  
Nucleation Sites ◽  
Lower Porosity ◽  
Effect Of Particle Size ◽  
Pore Microstructure ◽  
Directional Freezing

Porous Al2O3 ceramics with a lamellar pore microstructure have been fabricated by a directional freezing process using the micro-sized and nano-sized Al2O3 powders. At the same solid loading and freezing temperature, compared with the suspensions of micro-sized Al2O3, the porous ceramics prepared from the suspensions of nano-sized Al2O3 had the narrower lamellar pore channels and thicker channel walls, which were caused by the higher viscosity, stronger inter-particle attraction and more ice nucleation sites in the nano-sized Al2O3 suspensions. For both types of Al2O3 at a specific solid loading, with the increasing of freezing temperature, the wider pore channels and thinner channel walls were observed. These tendencies were weaker by using the nano-sized Al2O3 . The above results show the lower porosity in the ceramics using the nano-sized Al2O3. However, due to the higher sintering activity for the smaller particles, the pore channel walls by using the nano-sized Al2O3 was denser than using the micro-sized Al2O3, leading to the higher mechanical strength of ceramics.

scholarly journals Study on the Formation Law of the Freezing Temperature Field of Freezing Shaft Sinking under the Action of Large-Flow-Rate Groundwater

2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Bin Wang ◽  
Chuan-xin Rong ◽  
Jian Lin ◽  
Hua Cheng ◽  
Hai-bing Cai
Keyword(s):  
Temperature Field ◽  
Groundwater Flow ◽  
Flow Velocity ◽  
Flow Rate ◽  
Freezing Temperature ◽  
Freezing Process ◽  
Flow Rates ◽  
Porosity Reduction ◽  
Shaft Sinking ◽  
Large Flow

Taking into account moisture migration and heat change during the soil freezing process, as well as the influence of absolute porosity reduction on seepage during the freezing process, we construct a numerical model of hydrothermal coupling using laws of conservation of energy and mass. The model is verified by the results of large-scale laboratory tests. By applying the numerical calculation model to the formation of artificial shaft freezing temperature fields under the action of large-flow groundwater, we conclude that groundwater with flow rates of less than 5 m/d will not have a significant impact on the artificial freezing temperature field. The maximum flow rates that can be handled by single-row freezing pipes and double-row freezing pipes are 10 m/d and 20 m/d, respectively, during the process of freezing shaft sinking. By analyzing the variation of groundwater flow rate during freezing process, we find that the groundwater flow velocity can reach 5–7 times the initial flow velocity near the closure moment of the frozen wall. Finally, in light of the action characteristics of groundwater on the freezing temperature field, we make suggestions for optimal pipe and row spacing in freezing pipe arrangement.

scholarly journals Seasonal changes of sea-ice characteristics off East Antarctica

1994 ◽  
Vol 20 ◽  
pp. 195-201 ◽  
Author(s):  
Ian Allison ◽  
Anthony Worby
Keyword(s):  
Sea Ice ◽  
Ice Cores ◽  
Open Water ◽  
Ice Formation ◽  
Ice Thickness ◽  
Spatial And Temporal Variability ◽  
Growth Season ◽  
Ice Growth ◽  
Antarctic Sea Ice ◽  
Ice Edge

Data on Antarctic sea‐ice characteristics, and their spatial and temporal variability, are presented from cruises between 1986 and 1993 for the region spanning 60°−150° E between October and May. In spring, the sea‐ice zone is a variable mixture of different thicknesses of ice plus open water and in some regions only 30−40% of the area is covered with ice &gt;0.3 m thick. The thin‐ice and open‐water areas are important for air‐sea heat exchange. Crystallographic analyses of ice cores, supported by salinity and stable‐isotope measurements, show that approximately 50% of the ice mass is composed of small frazil crystals. These are formed by rapid ice growth in leads and polynyas and indicate the presence of open water throughout the growth season. The area‐averaged thickness of undeformed ice west of 120° E is typically less than 0.3 m and tends to‐increase with distance south of the ice edge. Ice growth by congelation freezing rarely exceeds 0.4 m, with increases in ice thickness beyond this mostly attributable to rafting and ridging. While most of the total area is thin ice or open water, in the central pack much of the total ice mass is contained in ridges. Taking account of the extent of ridging, the total area‐averaged ice thickness is estimated to be about 1m for the region 60°−90° E and 2 m for the region 120°−150° E. By December, new ice formation has ceased in all areas of the pack and only floes &gt;0.3 m remain. In most regions these melt completely over the summer and the new season's ice formation starts in late February. By March, the thin ice has reached a thickness of 0.15 0.30 m, with nilas formation being an important mechanism for ice growth within the ice edge

The Estimate of Sea Ice Thickness Based on the Relative Albedo of NOAA/AVHRR

2011 ◽  
Vol 356-360 ◽  
pp. 2816-2819
Author(s):  
Shuai Yuan ◽  
Wei Gu ◽  
Wei Bin Chen
Keyword(s):  
Sea Ice ◽  
Coastal Area ◽  
Preliminary Analysis ◽  
Bohai Sea ◽  
Average Error ◽  
Ice Thickness ◽  
Sea Ice Thickness ◽  
Noaa Avhrr ◽  
Avhrr Data ◽  
Ice Water

The estimate of sea ice thickness is the academic base of sea ice research in Bohai Sea. According to the ice-water spectrum differences and the correlation between ice thickness and albedo, this paper comes up with a sea ice thickness inversion model based on the relative albedo of NOAA/AVHRR data. The results are better in the coastal area and the average error of this method is about 21%. Then a preliminary analysis has been made on the errors of the estimate of sea ice thickness.

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