scholarly journals Centrifugal Modeling and Validation of Solute Transport within Unsaturated Zone

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 610
Author(s):  
Huanhuan Qin
Keyword(s):  
Numerical Modeling ◽  
Numerical Model ◽  
Solute Transport ◽  
Chemical Reactions ◽  
Unsaturated Zone ◽  
Poor Quality ◽  
Physical Processes ◽  
Transport Simulation ◽  
Reactive Solutes

Numerical modeling has been adopted to assess the feasibility of centrifugal simulation of solute transport within the unsaturated zone. A numerical model was developed to study the centrifugal simulation of nonreactive, adsorption, radionuclide, and reactive solutes. The results showed that it is feasible to conduct centrifugal experiments for nonreactive solute transport. For the solute transport containing physical processes or chemical reactions, if the reaction is very rapid or slow, it is feasible to conduct centrifugal experiments. For the solute transport with a product B generated, if the reaction is relatively slow, the centrifugal prediction of solute is suitable. The centrifugal prediction of solute A matches the prototype quite well, but the prediction of B is in poor quality. If B is the focus, it is not feasible to conduct centrifugal experiments; but if B is not important, the centrifugal modeling is suitable. This has significant implications for the centrifugal modeling application to solute transport simulation within the unsaturated zone.

scholarly journals Experimental and Numerical Study on Water Filling and Air Expelling Process in a Pipe with Multiple Air Valves under Water Slow Filling Condition

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2511
Author(s):  
Jintao Liu ◽  
Di Xu ◽  
Shaohui Zhang ◽  
Meijian Bai
Keyword(s):  
Numerical Model ◽  
Stokes Equations ◽  
Numerical Study ◽  
Practical Method ◽  
Navier Stokes ◽  
Physical Processes ◽  
Two Phase ◽  
Saint Venant Equations ◽  
Water Filling ◽  
Air Valve

This paper investigates the physical processes involved in the water filling and air expelling process of a pipe with multiple air valves under water slow filling condition, and develops a fully coupledwater–air two-phase stratified numerical model for simulating the process. In this model, the Saint-Venant equations and the Vertical Average Navier–Stokes equations (VANS) are respectively applied to describe the water and air in pipe, and the air valve model is introduced into the VANS equations of air as the source term. The finite-volume method and implicit dual time-stepping method (IDTS) with two-order accuracy are simultaneously used to solve this numerical model to realize the full coupling between water and air movement. Then, the model is validated by using the experimental data of the pressure evolution in pipe and the air velocity evolution of air valves, which respectively characterize the water filling and air expelling process. The results show that the model performs well in capturing the physical processes, and a reasonable agreement is obtained between numerical and experimental results. This agreement demonstrates that the proposed model in this paper offers a practical method for simulating water filling and air expelling process in a pipe with multiple air valves under water slow filling condition.

Analysis of the hybrid numerical model to study physical processes in the plasma

2020 ◽  
Author(s):  
Lyudmila Vshivkova ◽  
Vitaly Vshivkov ◽  
Galina Dudnikova
Keyword(s):  
Numerical Model ◽  
Physical Processes

Agricultural hillslope soil heterogeneity challenges: first experimental results from SUPREHILL critical zone observatory

2021 ◽  
Author(s):  
Vedran Krevh ◽  
Jasmina Defterdarović ◽  
Lana Filipović ◽  
Zoran Kovač ◽  
Steffen Beck-Broichsitter ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Soil Moisture ◽  
Solute Transport ◽  
Soil Water ◽  
Water Flow ◽  
Preferential Flow ◽  
Soil Heterogeneity ◽  
Local Scale ◽  
Soil Water Flow ◽  
Critical Zone Observatory

<p>SUPREHILL is a new (2020) and first Croatian critical zone observatory (CZO), focused on local scale agricultural e.g., vineyard hillslope processes. The experimental setup includes an extensive sensor-based network accompanied by weighing lysimeters and instruments for surface and subsurface hydrology measurement. The field measurements are supported by novel laboratory and numerical quantification methods for the determination of water flow and solute transport. This combined approach will allow the research team to accurately determine soil water balance components (soil water flow, preferential flow/transport pathways, surface runoff, evapotranspiration), the temporal origin of water in hillslope hydrology (isotopes), transport of agrochemicals, and to calibrate and validate numerical modeling procedures for describing and predicting soil water flow and solute transport. First results from sensors indicate increased soil moisture on the hilltop, which is supported by precipitation data from rain gauges and weighing lysimeters. The presence of a compacted soil horizon and compacted inter-row parts (due to trafficking) of the vineyard seems to be highly relevant in regulating water dynamics. Wick lysimeters confirm the sensor soil moisture data, while showing a significant difference in its repetitions which suggests a possibility of a preferential flow imposed by local scale soil heterogeneity. Measured values of surface and subsurface runoff suggest a crucial role of these processes in the hillslope hydrology, while slope and structure dynamics additionally influence soil hydraulic properties. We are confident that the CZO will give us new insights in the landscape heterogeneity and substantially increase our understanding regarding preferential flow and nonlinear solute transport, with results directly applicable in agricultural (sloped agricultural soil management) and environmental (soil and water) systems. Challenges remain in characterizing local scale soil heterogeneity, dynamic properties quantification and scaling issues for which we will rely on combining CZO focused measurements and numerical modeling after substantial data is collected.</p>

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