scholarly journals Blowing and drifting snow in Alpine terrain: numerical simulation and related field measurements

1998 ◽  
Vol 26 ◽  
pp. 174-178 ◽  
Author(s):  
Peter Gauer
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Three Dimensional ◽  
Field Measurements ◽  
Blowing Snow ◽  
Related Field ◽  
Drifting Snow ◽  
Physically Based ◽  
Snow Transport

A physically based numerical model of drifting and blowing snow in three-dimensional terrain is developed. The model includes snow transport by saltation and suspension. As an example, a numerical simulation for an Alpine ridge is presented and compared with field measurements.

scholarly journals Blowing and drifting snow in Alpine terrain: numerical simulation and related field measurements

1998 ◽  
Vol 26 ◽  
pp. 174-178 ◽  
Author(s):  
Peter Gauer
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Three Dimensional ◽  
Field Measurements ◽  
Blowing Snow ◽  
Related Field ◽  
Drifting Snow ◽  
Physically Based ◽  
Snow Transport

A physically based numerical model of drifting and blowing snow in three-dimensional terrain is developed. The model includes snow transport by saltation and suspension. As an example, a numerical simulation for an Alpine ridge is presented and compared with field measurements.

scholarly journals Numerical modeling of blowing and drifting snow in Alpine terrain

2001 ◽  
Vol 47 (156) ◽  
pp. 97-110 ◽  
Author(s):  
Peter Gauer
Keyword(s):  
Field Measurements ◽  
Erosion And Deposition ◽  
Mountainous Regions ◽  
Boundary Layer Equations ◽  
Trajectory Calculations ◽  
Drifting Snow ◽  
Physically Based ◽  
Turbulent Closure ◽  
Snow Distribution ◽  
Two Layer Model

AbstractIn mountainous regions, snow transport due to wind significantly influences snow distribution and, as a result, avalanche danger. A physically based numerical two-layer model is developed to simulate blowing and drifting snow in Alpine terrain. One layer describes the driving-wind field and the transport in suspension. The description is based on the atmospheric boundary-layer equations, using ane−∊model for the turbulent closure. The second layer describes the transport due to saltation, including erosion and deposition of snow. Here, conservation equations for mass and momentum are formulated for the mixture of snow and air. Particle trajectory calculations are used to parameterize quantities characterizing the saltation layer. Both layers are mutually coupled by boundary conditions. A two-way coupling between particles and airflow is taken into account. Comparisons between simulation results and field measurements around an Alpine crest show encouraging results.

scholarly journals A numerical geotechnical model for computing soil slides at banks of water reservoirs

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nils Reidar B. Olsen ◽  
Stefan Haun
Keyword(s):  
Numerical Model ◽  
Water Level ◽  
Stokes Equations ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Field Measurements ◽  
Navier Stokes ◽  
Adaptive Grids ◽  
Groundwater Levels ◽  
Before And After

AbstractSoil slides can occur when the water level in a lake or a reservoir is lowered. This may take place in situations when a reservoir is flushed to remove sediments. The current study describes a three-dimensional numerical model used for the simulation of reservoir flushing that includes the slide movements. The geotechnical failure algorithms start with modelling the groundwater levels at the banks of the reservoir. A limit equilibrium approach is further used to find the location of the slides. The actual movement of the sediments is computed by assuming the soil to be a viscous liquid and by solving the Navier–Stokes equations. The resulting bed elevation changes from the slides are computed in adaptive grids that change as a function of water level, bed erosion and slide movements. The numerical model is tested on the Bodendorf reservoir in Austria, where field measurements are available of the bank elevations before and after a flushing operation. The results from the numerical simulations are compared with these observations. A parameter test shows that the results are very sensitive to the cohesion and less sensitive to the E and G modules of the soil.

Numerical Modelling of Circulation in Lake Sperillen, Norway

2000 ◽  
Vol 31 (1) ◽  
pp. 57-72 ◽  
Author(s):  
N. R. B. Olsen ◽  
D. K. Lysne
Keyword(s):  
Numerical Model ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Field Measurements ◽  
Navier Stokes ◽  
Water Current ◽  
Simple Method ◽  
Vertical Temperature Profile ◽  
Navier Stokes Equations ◽  
Good Agreement

A three-dimensional numerical model was used to model water circulation and spatial variation of temperature in Lake Sperillen in Norway. A winter situation was simulated, with thermal stratification and ice cover. The numerical model solved the Navier-Stokes equations on a 3D unstructured non-orthogonal grid with hexahedral cells. The SIMPLE method was used for the pressure coupling and the k-ε model was used to model turbulence, with a modification for density stratification due to the vertical temperature profile. The results were compared with field measurements of the temperature in the lake, indicating the location of the water current. Reasonably good agreement was found.

scholarly journals Vibro-Acoustic Numerical Simulation for Analyzing Floor Noise of a Multi-Unit Residential Structure

2019 ◽  
Vol 9 (20) ◽  
pp. 4289 ◽  
Author(s):  
Sangki Park
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Numerical Model ◽  
South Korea ◽  
Acoustic Analysis ◽  
Measurement Data ◽  
Field Measurements ◽  
Story Structure ◽  
Residential Structures ◽  
Good Agreement

In South Korea, the construction of new multi-unit residential structures has been continuously increasing in order to accommodate multiple households in single structures. However, the presence of walls and floors shared with neighbors makes these structures exceptionally vulnerable to floor noise transmission when the noise of everyday life occurs. In particular, South Korea has many social problems associated with such floor noise, which require the utmost attention and immediate resolution. In this study, a 17-story structure was selected as a test structure. Field measurements were carried out. A numerical model for the 17-story structure was developed in order to perform a vibro-acoustic analysis. The validation of the numerical model comparing with the field measurement data results shows a good agreement. Finally, it is concluded that numerical analysis can be applied to resolve floor noise problems arising in multi-unit residential structures.

scholarly journals Drifting snow statistics from multiple-year autonomous measurements in Adelie Land, eastern Antarctica

2019 ◽  
Author(s):  
Charles Amory
Keyword(s):  
Temporal Frequency ◽  
Field Measurements ◽  
Near Surface ◽  
Continental Scale ◽  
Drifting Snow ◽  
Single Location ◽  
Antarctic Continent ◽  
Short Time ◽  
The Antarctic ◽  
Snow Transport

Abstract. Drifting snow is a widespread feature over the Antarctic ice sheet whose climatological and hydrological significances at the continental scale have been consequently investigated through modelling and satellite approaches. While field measurements are needed to evaluate and interpret model and punctual satellite products, most drifting snow observation campaigns in Antarctica involved data collected at a single location and over short time periods. With the aim of acquiring new data relevant to the observations and modelling of drifting snow in Antarctic conditions, two remote locations in coastal Adelie Land (East Antarctica) 100 km apart were instrumented in January 2010 with meteorological and second-generation IAV Engineering acoustic FlowCaptTM sensors. The data provided nearly continuously so far constitutes the longest dataset of autonomous near-surface (i.e., below 2 m) measurements of drifting snow currently available over the Antarctic continent. This paper presents an assessment of drifting snow occurrences and snow mass transport from up to 9 years (2010–2018) of half-hourly observational records collected in one of the Antarctic regions most prone to snow transport by wind. The dataset is freely available to the scientific community and can be used to complement satellite products and evaluate snow-transport models close to the surface and at high temporal frequency.

The use of static chambers in drip irrigation: what should be considered?

2021 ◽  
Author(s):  
Shahar Baram ◽  
Asher Bar-Tal ◽  
Alon Gal ◽  
David Russo
Keyword(s):  
Drip Irrigation ◽  
Three Dimensional ◽  
Ghg Emissions ◽  
Field Measurements ◽  
Nitrogen Transformations ◽  
Nutrient Distribution ◽  
Capillary Length ◽  
Flow Transport ◽  
Physically Based ◽  
Water Contents

<p>Static chambers are frequently used to evaluate greenhouse gas (GHG) emissions from agro-systems. However, the effects of such chambers on water and nutrient distribution within and under the chamber’s base (i.e., anchor) in drip irrigation and its effects on GHG emissions is not well understood. This study aimed to shed some light on the topic by using field measurements and physically based, three-dimensional (3-D) simulations of flow transport and nitrogen transformations in variably saturated, spatially heterogeneous flow domain. GHG fluxes [methane (CH<sub>4</sub>), carbon dioxide (CO<sub>2</sub>), and nitrous oxide (N<sub>2</sub>O)] were measured in the field for two years using a portable FTIR gas analyzer. The main findings of this study suggest that: (i) the chamber’s base modifies the water and nutrient distribution within it. Placement of the dripper inside the base leads to higher water contents, higher nitrate and ammonium concentrations, and higher N<sub>2</sub>O fluxes relative to an undisturbed area. In contrast, placement of the dripper outside the chamber base reduces all of these parameters, including the N<sub>2</sub>O fluxes, relative to an undisturbed area. (ii) The dripper’s location relative to the chamber’s base had minor to no effect on CO<sub>2</sub> fluxes. The effect on the CH<sub>4</sub> fluxes was not conclusive, yet suggested higher emissions when the dripper was located inside the base. (iii) A minimal disturbance is achieved when the dripper is located within a base, and the base’s radius equals the capillary length of the soil.</p>

scholarly journals A numerical model of blowing snow around an Antarctic building

1994 ◽  
Vol 20 ◽  
pp. 341-346
Author(s):  
I. Moore ◽  
S.D. Mobbs ◽  
D.B. Ingham ◽  
J.C. King
Keyword(s):  
Numerical Model ◽  
Qualitative Agreement ◽  
Progress Report ◽  
Blowing Snow ◽  
Ice Shelf ◽  
British Antarctic Survey ◽  
Drifting Snow ◽  
Antarctic Continent ◽  
Useful Life ◽  
The Antarctic

The accumulation of drifting snow around buildings in regions of severe climate has important implications on their design and location. This paper studies one such building, at a station run by the British Antarctic Survey and located on the Brunt Ice Shelf at the edge of the Antarctic continent. Four previous stations have been built in the area, the buildings of which were designed to become covered in snow and all have been crushed within a few years. The current station, Halley V, consists of three buildings which are all raised from the ice shelf by means of legs. They were designed in such a way that the action of the wind blowing underneath the buildings would keep them-clear of snow. This paper describes a model which predicts the shape and position of drift formation, and then compares the results with those observed at Halley. This model is a first attempt to address the problem and as such the paper can be considered to be a progress report; improvements arc currently being made as part of continuing research. It is found that there is some qualitative agreement and possible reasons for a few quantitative discrepancies are discussed. Both the model and the true data show clearly that the new design is very effective in prolonging the useful life of the buildings.

Numerical Simulation of Vertical Forced Plume in a Crossflow of Stably Stratified Fluid

1995 ◽  
Vol 117 (4) ◽  
pp. 696-705 ◽  
Author(s):  
Robert R. Hwang ◽  
T. P. Chiang
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Cross Section ◽  
Three Dimensional ◽  
Experimental Measurements ◽  
Secondary Vortex ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Vortex Pairs ◽  
Plume Flows

In this study, an investigation using a three-dimensional numerical model, which treats conservation of mass, momentum, and salinity simultaneously, was carried out to study the character of a vertical forced plume in a uniform cross-stream of stably linear stratified environment. A k-ε turbulence model was used to simulate the turbulent phenomena and close the solving problem. The performance of the three-dimensional model is evaluated by comparison of the numerical results with some available experimental measurements. Results indicate that the numerical computation simulates satisfactorily the plume behavior in a stratified crossflow. The secondary vortex pairs in the cross section induced by the primary one change as the plume flows downstream. This denotes the transformation of entrainment mechanism in stratified crossflow.

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