Implementation of a Microscopic Soil-Root Hydraulic Conductivity Drop Function in a Three-Dimensional Soil-Root Architecture Water Transfer Model

2009 ◽  
Vol 8 (3) ◽  
pp. 783-792 ◽  
Author(s):  
Tom Schröder ◽  
Mathieu Javaux ◽  
Jan Vanderborght ◽  
Bernd Körfgen ◽  
Harry Vereecken
Keyword(s):  
Hydraulic Conductivity ◽  
Root Architecture ◽  
Three Dimensional ◽  
Water Transfer ◽  
Transfer Model ◽  
Root Hydraulic Conductivity

scholarly journals A grid refinement approach for a three-dimensional soil-root water transfer model

2009 ◽  
Vol 45 (10) ◽  
Author(s):  
T. Schröder ◽  
L. Tang ◽  
M. Javaux ◽  
J. Vanderborght ◽  
B. Körfgen ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Water Transfer ◽  
Transfer Model ◽  
Grid Refinement

scholarly journals A Proof-of-Concept Algorithm for the Retrieval of Total Column Amount of Trace Gases in a Multi-Dimensional Atmosphere

2021 ◽  
Vol 13 (2) ◽  
pp. 270
Author(s):  
Adrian Doicu ◽  
Dmitry S. Efremenko ◽  
Thomas Trautmann
Keyword(s):  
Trace Gases ◽  
Three Dimensional ◽  
Principal Component ◽  
Radiative Transfer Model ◽  
Computational Time ◽  
Transfer Model ◽  
Proof Of Concept ◽  
Discrete Ordinate ◽  
Distribution Method ◽  
Total Column

An algorithm for the retrieval of total column amount of trace gases in a multi-dimensional atmosphere is designed. The algorithm uses (i) certain differential radiance models with internal and external closures as inversion models, (ii) the iteratively regularized Gauss–Newton method as a regularization tool, and (iii) the spherical harmonics discrete ordinate method (SHDOM) as linearized radiative transfer model. For efficiency reasons, SHDOM is equipped with a spectral acceleration approach that combines the correlated k-distribution method with the principal component analysis. The algorithm is used to retrieve the total column amount of nitrogen for two- and three-dimensional cloudy scenes. Although for three-dimensional geometries, the computational time is high, the main concepts of the algorithm are correct and the retrieval results are accurate.

scholarly journals The Singular Molecular Conformation of Humic Acids in Solution Influences Their Ability to Enhance Root Hydraulic Conductivity and Plant Growth

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 3
Author(s):  
Maite Olaetxea ◽  
Veronica Mora ◽  
Roberto Baigorri ◽  
Angel M. Zamarreño ◽  
Jose M. García-Mina
Keyword(s):  
Polyethylene Glycol ◽  
Humic Acid ◽  
Hydraulic Conductivity ◽  
Plant Growth ◽  
Polyacrylic Acid ◽  
Molecular Conformation ◽  
Water Solution ◽  
Biological Effects ◽  
Root Hydraulic Conductivity ◽  
Molecular Systems

Some studies have reported that the capacity of humic substances to improve plant growth is dependent on their ability to increase root hydraulic conductivity. It was proposed that this effect is directly related to the structural conformation in solution of these substances. To study this hypothesis, the effects on root hydraulic conductivity and growth of cucumber plants of a sedimentary humic acid and two polymers—polyacrylic acid and polyethylene glycol—presenting a molecular conformation in water solution different from that of the humic acid have been studied. The results show that whereas the humic acid caused an increase in root hydraulic conductivity and plant growth, both the polyacrylic acid and the polyethylene glycol did not modify plant growth and caused a decrease in root hydraulic conductivity. These results can be explained by the different molecular conformation in water solution of the three molecular systems. The relationships between these biological effects and the molecular conformation of the three molecular systems in water solution are discussed.

scholarly journals Three-dimensional hydraulic conductivity upscaling in groundwater modeling

2010 ◽  
Vol 36 (10) ◽  
pp. 1224-1235 ◽  
Author(s):  
Haiyan Zhou ◽  
Liangping Li ◽  
J. Jaime Gómez-Hernández
Keyword(s):  
Hydraulic Conductivity ◽  
Groundwater Modeling ◽  
Three Dimensional

Study on Three-Dimensional Visual Simulation for Inter-Basin Water Transfer Project

2012 ◽  
Vol 256-259 ◽  
pp. 2523-2527
Author(s):  
Qian Wei Wang ◽  
Rui Rui Sun ◽  
Wei Ping Guo
Keyword(s):  
Three Dimensional ◽  
Google Earth ◽  
Water Transfer ◽  
Digital Model ◽  
Water Diversion ◽  
Visual Simulation ◽  
Channel Water ◽  
North Water ◽  
Basin Water

With regards to the characteristics of inter-basin water transfer projects, a 3d visual simulation (Three-Dimensional Visual Simulation, 3DVS) method for inter-basin water transfer project was proposed. A virtual reproduction of the entire project and its topography is achieved. The supplement of the three-dimensional topographic data was completed by Civil 3D combinedwith Google Earth. In this paper, the 3D digital model of inter-basin water transfer project is established using 3ds Max. Based on the established digital model, the simulation of channel water were realized .The Yuzhou section of South-to-North Water Transfer Project is taken as a case study. 3D visual simulation provides an effective way for the construction management and decision-making for inter-basin water diversion project.

Transient Three-Dimensional Heat Transfer Model of a Solar Thermochemical Reactor for H2O and CO2 Splitting via Nonstoichiometric Ceria Redox Cycling

2013 ◽  
Author(s):  
Justin Lapp ◽  
Wojciech Lipiński
Keyword(s):  
Heat Transfer ◽  
Heat Recovery ◽  
Fuel Efficiency ◽  
Three Dimensional ◽  
Reactor Design ◽  
Heat Transfer Model ◽  
Heat Fluxes ◽  
Transfer Model ◽  
Rotating Cylinders ◽  
Solar Receiver

A transient heat transfer model is developed for a solar reactor prototype for H2O and CO2 splitting via two-step non-stoichiometric ceria cycling. Counter-rotating cylinders of reactive and inert materials cycling between high and low temperature zones permit continuous operation and heat recovery. To guide the reactor design a transient three-dimensional heat transfer model is developed based on transient energy conservation, accounting for conduction, convection, radiation, and chemical reactions. The model domain includes the rotating cylinders, a solar receiver cavity, and insulated reactor body. Radiative heat transfer is analyzed using a combination of the Monte Carlo method, Rosseland diffusion approximation, and the net radiation method. Quasi-steady state distributions of temperatures, heat fluxes, and the non-stoichiometric coefficient are reported. Ceria cycles between temperatures of 1708 K and 1376 K. A heat recovery effectiveness of 28% and solar-to-fuel efficiency of 5.2% are predicted for an unoptimized reactor design.

scholarly journals Accelerated RAPID Model Using Heterogeneous Porous Objects

2018 ◽  
Vol 10 (8) ◽  
pp. 1264 ◽  
Author(s):  
Huaguo Huang
Keyword(s):  
Three Dimensional ◽  
Computation Time ◽  
Single Scattering ◽  
Projection Algorithm ◽  
Forest Plot ◽  
Transfer Model ◽  
Bidirectional Reflectance Factor ◽  
Reflectance Factor ◽  
Radiation Transfer Model ◽  
Porous Object

To enhance the capability of three-dimensional (3D) radiative transfer models at the kilometer scale (km-scale), the radiosity applicable to porous individual objects (RAPID) model has been upgraded to RAPID3. The major innovation is that the homogeneous porous object concept (HOMOBJ) used for a tree crown scale is extended to a heterogeneous porous object (HETOBJ) for a forest plot scale. Correspondingly, the radiosity-graphics-combined method has been extended from HOMOBJ to HETOBJ, including the random dynamic projection algorithm, the updated modules of view factors, the single scattering estimation, the multiple scattering solutions, and the bidirectional reflectance factor (BRF) calculations. Five cases of the third radiation transfer model intercomparison (RAMI-3) have been used to verify RAPID3 by the RAMI-3 online checker. Seven scenes with different degrees of topography (valleys and hills) at 500 m size have also been simulated. Using a personal computer (CPU 2.5 GHz, memory 4 GB), the computation time of BRF at 500 m is only approximately 13 min per scene. The mean root mean square error is 0.015. RAPID3 simulated the enhanced contrast of BRF between backward and forward directions due to topography. RAPID3 has been integrated into the free RAPID platform, which should be very useful for the remote sensing community. In addition, the HETOBJ concept may also be useful for the speedup of ray tracing models.

scholarly journals Fast three-dimensional heat transfer model for computing internal temperatures in the bearing housing of automotive turbochargers

2018 ◽  
Vol 21 (8) ◽  
pp. 1286-1297 ◽  
Author(s):  
Antonio Gil ◽  
Andrés Omar Tiseira ◽  
Luis Miguel García-Cuevas ◽  
Tatiana Rodríguez Usaquén ◽  
Guillaume Mijotte
Keyword(s):  
Heat Transfer ◽  
Coke Formation ◽  
Three Dimensional ◽  
Heat Transfer Model ◽  
Operating Conditions ◽  
Thermal Design ◽  
Working Fluid ◽  
Transfer Model ◽  
Lumped Model ◽  
Bearing System

Each of the elements that make up the turbocharger has been gradually improved. In order to ensure that the system does not experience any mechanical failures or loss of efficiency, it is important to study which engine-operating conditions could produce the highest failing rate. Common failing conditions in turbochargers are mostly achieved due to oil contamination and high temperatures in the bearing system. Thermal management becomes increasingly important for the required engine performance. Therefore, it has become necessary to have accurate temperature and heat transfer models. Most thermal design and analysis codes need data for validation; often the data available fall outside the range of conditions the engine experiences in reality leading to the need to interpolate and extrapolate disproportionately. This article presents a fast three-dimensional heat transfer model for computing internal temperatures in the central housing for non-water cooled turbochargers and its direct validation with experimental data at different engine-operating conditions of speed and load. The presented model allows a detailed study of the temperature rise of the central housing, lubrication channels, and maximum level of temperature at different points of the bearing system of an automotive turbocharger. It will let to evaluate thermal damage done to the system itself and influences on the working fluid temperatures, which leads to oil coke formation that can affect the performance of the engine. Thermal heat transfer properties obtained from this model can be used to feed and improve a radial lumped model of heat transfer that predicts only local internal temperatures. Model validation is illustrated, and finally, the main results are discussed.

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