Modeling the impact of partial surface mulch on soil heat and water flow

1996 ◽  
Vol 54 (1-2) ◽  
pp. 85-98 ◽  
Author(s):  
K. L. Bristow ◽  
R. Horton
Keyword(s):  
Water Flow ◽  
The Impact

scholarly journals Ethylene Yield from Pyrolysis Cracking in Olefin Plant Utilizing Regression Analysis

2021 ◽  
Vol 287 ◽  
pp. 03004
Author(s):  
Mohamad Hafizi Zakria ◽  
Mohd Ghazali Mohd Nawawi ◽  
Mohd Rizal Abdul Rahman
Keyword(s):  
Regression Analysis ◽  
Water Flow ◽  
Large Scale ◽  
Nox Emission ◽  
Feed Water ◽  
Yield Model ◽  
Liquid Feed ◽  
The Impact ◽  
Steam Drum ◽  
Boiler Feed Water

Ethylene yield is significant in showing the performance of the steam cracker furnace in the olefin plant. This study was conducted in the actual large-scale olefin plant to see the impact of various variables towards the ethylene yield. The analysis was conducted utilizing Regression Analysis in Minitab Software Version 18 to develop a reliable ethylene yield model. The model concluded that ethylene yield in the studied plant was contributed by the factor of -0.000901, 0.02649, -0.282, 0.16, -0.0834, 0.1268, and 0.0057 of Hearth Burner Flow, Integral Burner Flow, Steam Drum Pressure, Super High-Pressure Steam (SHP) Boiler Feed Water Flow, SHP Flow, Naphtha Feed Flow, and Stack NOx Emission respectively. The Response Optimizer tool also showed that the ethylene yield from naphtha liquid feed utilizing pyrolysis cracking can be maximized at 32.55% with control setting at 9,476.41 kg/hr of Hearth Burner Flow, 608.56 kg/hr of Integral Burner Flow, 112.93 Barg of Steam Drum Pressure, 109.11 t/hr of SHP Boiler Feed Water Flow, 86.42 t/hr of SHP Flow, 63.49 t/hr of Naphtha Feed Flow and 126.23 mg/m3 of Stack NOx Emission.

scholarly journals Analysis of Water Flow Pressure on Bridge Piers considering the Impact Effect

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Yin-hui Wang ◽  
Yi-song Zou ◽  
Lue-qin Xu ◽  
Zheng Luo
Keyword(s):  
Water Flow ◽  
Coupling Effect ◽  
Highway Bridges ◽  
Element Model ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Water Current ◽  
Fluid Structure ◽  
Impact Effect ◽  
The Impact

In order to investigate the effects of water current impact and fluid-structure interaction on the bridge piers, the mechanism of water flow impact on the bridge pier is firstly studied. Then a finite element model of a bridge pier is established including the effects of water flow impact as well as the water circumferential motion around the pier. Comparative study is conducted between the results of water impact effect, fluid-structure coupling effect, theoretical analysis, and also the results derived using the formulas specified in the design codes home and abroad. The results show that the water flow force calculated using the formulas provided by the codes should be multiplied by an impact amplifier to account for the effect of flood impact on the bridge pier. When the flood flows around the pier, the fluid-structure coupling effect on the bridge pier can be neglected. The method specified in the China guidelines ofGeneral Code for Design of Highway Bridges and Culvertstends to provide a larger result of the water flow force.

scholarly journals Air trapping problem during infiltration on the large areas

2018 ◽  
Vol 44 ◽  
pp. 00178
Author(s):  
Witold Tisler ◽  
Adam Szymkiewicz
Keyword(s):  
Water Flow ◽  
Richards Equation ◽  
Shallow Water Table ◽  
Two Phase ◽  
Infiltration Process ◽  
Soil Skeleton ◽  
Irrigation Effect ◽  
Volume Method ◽  
The Impact ◽  
Trapping Problem

The process of flow modeling in unsaturated porous medium is often found in many fields of sciences: geology, fluid mechanics, thermodynamics, microbiology or chemistry. Problem is relatively complicated due to complexity of the system which contains three phases: water, air and soil skeleton. The flow of water in such a medium can be described using two-phase (2PH) flow formulation, which accounts the inflow of air and water phases, or with simplified model known as Richards (RE) equation where only water flow is taken into account. In many well known programs available in the market (like SeepW, STOMP) the primary interest is only the water flow and the flow of air is omitted. As a result Richard equation in used more often. It’s main assumption is that pore air is continuous and has connection with atmospheric air which is equivalent to infinite mobility of the air phase during all simulation. This paper presents a brief review of the influence of the air phase in soil on water flow and pore pressure generation, with focus on applications related to infiltration process occurring in the large areas. An irrigation effect of rice fields with shallow water table has been investigated. To assess the impact of the gas phase various lengths of the infiltration zone have been considered. Numerical simulations are carried out to investigate the differences between the Richards equation and the two-phase flow model, using an in-house code based on the finite volume method.

scholarly journals Effects of Spur Dikes on Water Flow Diversity and Fish Aggregation

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1822
Author(s):  
Tingjie Huang ◽  
Yan Lu ◽  
Huaixiang Liu
Keyword(s):  
Water Flow ◽  
Diversity Index ◽  
Spur Dike ◽  
Rock Fill ◽  
Aggregation Rate ◽  
Different Types ◽  
Spur Dikes ◽  
Fish Aggregation ◽  
The Impact ◽  
The Relationship

As a typical waterway modification, the spur dike narrows the water cross section, which increases the flow velocity and flushes the riverbed. Meanwhile, it also protects ecological diversity and improves river habitat. Different types of spur dikes could greatly impact the interaction between flow structure and local geomorphology, which in turn affects the evolution of river aquatic habitats. Four different types of spur dikes—including rock-fill, permeable, w-shaped rock-fill, and w-shaped permeable—were evaluated using flume experiments for spur dike hydrodynamics and fish aggregation effects. Based on Shannon’s entropy, an index for calculating water flow diversity is proposed. Additionally, the impact of the different spur dikes on water flow diversity and the relationship between water flow diversity and fish aggregation effects were studied. The water flow diversity index around the spur dike varied from 1.13 to 2.96. The average aggregation rate of test fish around the spur dike was 5% to 28%, and the attraction effect increased with increasing water flow diversity. Furthermore, we plotted the relationship between water flow diversity index and average fish aggregation rate. A fish hydroacoustic study conducted on the Laohutan fish-bone dike in the Dongliu reach of downstream Yangtze River showed that the fish aggregation effect of the permeable spur dike was greater than the rock-fill spur dike. These research results could provide theoretical support for habitat heterogeneity research and ecologically optimal design of spur dikes.

ANALYTICAL REVIEW OF INVESTIGATIONS OF THE CLIMATE CHANGE IMPACT ON RIVER WATER FLOW

2019 ◽  
pp. 64-73
Author(s):  
Hanna Bolbot ◽  
Vasyl Grebin
Keyword(s):  
Climate Change ◽  
Water Balance ◽  
Water Flow ◽  
Hydrological Modeling ◽  
Complex Method ◽  
Water Runoff ◽  
Impact Of Climate Change ◽  
Insufficient Attention ◽  
The World ◽  
The Impact

A huge number of scientific researches in the world are devoted to the research of global and regional climate change and their impact on water resources. In Ukraine, this issue is receiving insufficient attention. Researches have been done to assess current trends in river runoff, but future estimates of changes in Ukraine’s water flow have been presented in only a few papers. Present studies of this issue are conducted using hydrological modeling. The ensemble approach is widely used to increase the reliability of estimates of possible future changes in water runoff, that is, the use of data from several GCM and RCM models, with subsequent averaging of their results. Unfortunately, this methodological approach was not used in Ukraine. Using the water-balance method, local manifestations of global climate change within individual catchments can be estimated with sufficient quality. To estimate the temporal variability of the components of the water balance, a comparison of the available hydrological and climatic characteristics of the current period with the period of the climatic norm is used, as well as the method of differential integral curves, which reflects characteristic tendencies in the long-term dynamics of individual components of the water balance. Analyzing all available approaches to research on the impact of climate change on water flow, we can conclude that a complex method is the best for this investigation. Given that a large number of methods are used in the world, reliable estimates can be obtained by developing unified and validated methods and techniques. Therefore, the first step in this way should be a comparative analysis of the results obtained by the most commonly used methods. In the field of water, climate change can lead to changes in rainfall, hydrodynamic regime and water balance of rivers, increase of catastrophic floods and excessive drought, shortage of fresh water. Unfortunately, there is insufficient attention paid to the study of this issue in Ukraine. That is why assessing the impact of climate change on water flow and forecasting them is a very necessary task.

Structure Design of the ANSYS-Based SLC9-2-Type Direct Reading Current Meter

2014 ◽  
Vol 926-930 ◽  
pp. 1412-1416
Author(s):  
Shi Ming Wang ◽  
Zhen Wang ◽  
Qing Yi He ◽  
Jie Zhang ◽  
Yu Qing Zhang
Keyword(s):  
Water Flow ◽  
Flow Measurement ◽  
Simulation Analysis ◽  
Flow Speed ◽  
Structure Design ◽  
Measurement Instruments ◽  
Ansys Software ◽  
Direct Reading ◽  
Simulation Results ◽  
The Impact

SLC9-2-type direct reading; current meter is a lightweight, reliable, affordable, low consumption of the new flow measurement instruments, available for measuring the different depth of water flow speed and direction in the ocean, bays, rivers, lakes, reservoirs, estuaries . By improving its structure, using the simulation analysis of ANSYS software, it analyzes the new structure on the impact of lowing start. Simulation results for the actual SLC9-2-type direct reading current meter provide guidance for new design.

scholarly journals Analysing the impact of compaction of soil aggregates using X-ray microtomography and water flow simulations

2015 ◽  
Vol 150 ◽  
pp. 147-157 ◽  
Author(s):  
M. Menon ◽  
X. Jia ◽  
G.J. Lair ◽  
P.H. Faraj ◽  
A. Blaud
Keyword(s):  
Water Flow ◽  
Soil Aggregates ◽  
X Ray ◽  
Flow Simulations ◽  
The Impact
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