A two-dimensional shallow ice-flow model of Glacier de Saint-Sorlin, France

AbstractA two-dimensional ice-flow model based on the shallow-ice approximation (SIA) is used to investigate the dynamics of Glacier de Saint-Sorlin, France. This glacier is well suited for this kind of study. First, the particular geometry of the glacier itself as well as that of the bedrock surface allows for correct applicability of the SIA (zeroth-order equations), provided that thickness changes and termini positions rather than short-scale dynamics are considered. Secondly, the wealth of available data for the glacier including mass-balance series and records of glacier changes provides a reliable forcing and a powerful constraining set for the model. Steady-state simulations show realistic results and the capabilities of the model in reproducing the glacier extent at the beginning of the 20th century. An extensive parameter study of ice rheology and sliding intensity is also carried out and the results are checked against the thickness changes as well as the glacier termini positions since 1905. It is possible to find a parameter combination that best matches these two types of data with an ice-flow rate factor of 2 × 10−24 Pa−3 s−1 and a Weertman-type sliding factor of 5 × 10−14 m8 N−3 a−1 which both appear to be in agreement with similar inferences from recent modelling attempts.

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Numerical modelling of the historic front variation and the future behaviour of the Pasterze glacier, Austria

Annals of Glaciology ◽

10.3189/s0260305500012234 ◽

1997 ◽

Vol 24 ◽

pp. 234-241 ◽

Cited By ~ 6

Author(s):

Z. Zuo ◽

J. Oerlemans

Keyword(s):

Steady State ◽

Flow Model ◽

Calibration Method ◽

Climate Scenarios ◽

Ice Dynamics ◽

Ice Flow ◽

Steady State Condition ◽

Ice Volume ◽

Future Warming ◽

Dynamic Calibration Method

An ice-flow model is used to simulate the front variations of the Pasterze glacier, Austria. The model deals explicitly with the ice flux from sub-streams and tributaries to the main ice stream. The dynamic calibration method adopted successfully calibrates the ice-flow model under a non-steady-state condition. Despite the complexity of the glacier geometry, the ice dynamics of the Pasterze are adequately simulated.Results of the sensitivity experiments suggest that the Pasterze glacier has been in a non-steady state most of the time and has a response time of 34–50 years.Projections of the behaviour of the Pasterze in the next 100 years are made under various climate scenarios. Results suggest that the Pasterze will undergo a substantial retreat if there is future warming. The glacier is likely to retreat 2–5 km by the year 2100. The ice volume could be reduced by 24–63% by the end of the 21st century.

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Sensitivity analysis of two-dimensional steady-state aquifer flow equations. Implications for groundwater flow model calibration and validation

Advances in Water Resources ◽

10.1016/j.advwatres.2010.04.014 ◽

2010 ◽

Vol 33 (8) ◽

pp. 905-922 ◽

Cited By ~ 7

Author(s):

N. Mazzilli ◽

V. Guinot ◽

H. Jourde

Keyword(s):

Sensitivity Analysis ◽

Steady State ◽

Model Calibration ◽

Flow Model ◽

Groundwater Flow Model ◽

Two Dimensional ◽

Flow Equations ◽

Calibration And Validation ◽

Model Calibration And Validation ◽

Aquifer Flow

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Comments on “An investigation of the thermo-mechanical features of Laohugou Glacier No. 12 in Mt. Qilian Shan, western China, using a two-dimensional first-order flow-band ice flow model”

10.5194/tc-2016-38-sc1 ◽

2016 ◽

Author(s):

Kristin Poinar

Keyword(s):

Flow Model ◽

Western China ◽

Order Flow ◽

Two Dimensional ◽

Ice Flow ◽

First Order ◽

Flow Band

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Steady-State Tilting-Pad Bearing Performance Under Reduced Oil Supply Flow Rates

Journal of Tribology ◽

10.1115/1.4039408 ◽

2018 ◽

Vol 140 (5) ◽

Cited By ~ 3

Author(s):

Bradley R. Nichols ◽

Roger L. Fittro ◽

Christopher P. Goyne

Keyword(s):

Experimental Data ◽

Steady State ◽

Flow Rate ◽

Flow Model ◽

Leading Edge ◽

Input Power ◽

Flow Rates ◽

Flow Models ◽

Oil Supply ◽

Tilting Pad

Reduced oil supply flow rates in fluid film bearings can cause cavitation, or lack of a fully developed hydrodynamic film layer, at the leading edge of the bearing pads. Reduced oil flow has the well-documented effects of higher bearing operating temperatures and decreased power losses and is commonly referred to as starvation. This study looks at the effects of oil supply flow rate on steady-state bearing performance and provides increased experimental data for comparison to computational predictions. Tests are conducted on a five-pad tilting-pad bearing positioned in a vintage, flooded housing with oil supply nozzles. Pad temperatures, sump temperature, journal operating position, and motor input power are measured at various operating speeds ranging from 2000 to 12,000 rpm and various oil supply flow rates. Predicted results are obtained from bearing modeling software based on thermoelastohydrodynamic (TEHD) lubrication theory. A starved flow model was previously developed as an improvement over the original flooded flow model to more accurately capture bearing behavior under reduced flow conditions. Experimental results are compared to both flow models. The starved bearing model predicts significantly higher journal operating positions than the flooded model and shows good correlation with the experimental data. Predicted pressure profiles from the starved bearing model show cavitation of the upper unloaded pads that increase in severity with increasing speed and decreasing oil supply flow rate. The progressive unloading of these top pads explains the rise in shaft centerline position and helps further validate the starvation model.

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Numerical modelling of the historic front variation and the future behaviour of the Pasterze glacier, Austria

Annals of Glaciology ◽

10.1017/s0260305500012234 ◽

1997 ◽

Vol 24 ◽

pp. 234-241 ◽

Cited By ~ 22

Author(s):

Z. Zuo ◽

J. Oerlemans

Keyword(s):

Steady State ◽

Flow Model ◽

Calibration Method ◽

Climate Scenarios ◽

Ice Dynamics ◽

Ice Flow ◽

Steady State Condition ◽

Ice Volume ◽

Future Warming ◽

Dynamic Calibration Method

An ice-flow model is used to simulate the front variations of the Pasterze glacier, Austria. The model deals explicitly with the ice flux from sub-streams and tributaries to the main ice stream. The dynamic calibration method adopted successfully calibrates the ice-flow model under a non-steady-state condition. Despite the complexity of the glacier geometry, the ice dynamics of the Pasterze are adequately simulated. Results of the sensitivity experiments suggest that the Pasterze glacier has been in a non-steady state most of the time and has a response time of 34–50 years. Projections of the behaviour of the Pasterze in the next 100 years are made under various climate scenarios. Results suggest that the Pasterze will undergo a substantial retreat if there is future warming. The glacier is likely to retreat 2–5 km by the year 2100. The ice volume could be reduced by 24–63% by the end of the 21st century.

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A coupling flow model for fractured horizontal well and anisotropic tight gas reservoir

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01086-5 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1873-1883

Author(s):

P. Q. Lian ◽

C. Y. Ma ◽

T. Z. Duan ◽

H. W. Zhao

Keyword(s):

Steady State ◽

Flow Rate ◽

Horizontal Well ◽

Flow Model ◽

Horizontal Wells ◽

Tight Gas ◽

Unsteady State ◽

Gas Reservoir ◽

Fractured Horizontal Well ◽

Tight Gas Reservoir

AbstractThe development of multistage fracturing technology in horizontal wells is a great impulsion to the successful development of unconventional resources. The hydraulic fractures distribute regularly along the horizontal wellbore, forming a seepage channel for fluids in tight gas reservoir and greatly improving the productivity of horizontal wells. Based on Green function and Neumann product principle, we establish a flow model of fractured horizontal well coupled with anisotropic tight gas reservoir under both unsteady state and pseudo-steady state and propose a method to solve this model. The calculation results show that flow rate of horizontal well under the early unsteady state is larger than that under the pseudo-steady state. There is no interference among fractures in the early unsteady state, and flow rate is in direct proportion to fracture numbers. Affected by frictional and acceleration pressure drop, flow rate of the end fractures is obviously larger than other fractures in pseudo-steady state. The permeabilities in different directions have great influence on well flow rate distribution. With the increasing Kx, the interference between the fractures is reduced, and the flow distribution is more balanced. When Ky becomes larger, the interference between fractures are stronger, and the “U” shape distribution of the wellbore flow is more significant.

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