A New Approach to Simulation of the Boundary Layer in the Vapor Extraction Process

2009 ◽  
Author(s):  
H. Nourozieh ◽  
M. Kariznovi ◽  
J. Abedi ◽  
Z. Chen
Keyword(s):  
Boundary Layer ◽  
Extraction Process ◽  
Vapor Extraction ◽  
New Approach

A New Approach To Simulate the Boundary Layer in the Vapour Extraction Process

2011 ◽  
Vol 50 (11/12) ◽  
pp. 11-18 ◽  
Author(s):  
Hossein Nourozieh ◽  
Mohammad Kariznovi ◽  
Jalal Abedi ◽  
Zhangxing John Chen
Keyword(s):  
Boundary Layer ◽  
Extraction Process ◽  
New Approach ◽  
Vapour Extraction

Steady State Analysis of Heated Soil Vapor Extraction Process With Air Sparging

2005 ◽  
Author(s):  
P. M. Mohan Das ◽  
R. S. Amano ◽  
T. Roy ◽  
J. Jatkar
Keyword(s):  
Extraction Process ◽  
Soil Vapor Extraction ◽  
Air Sparging ◽  
Saturated Zone ◽  
Vapor Extraction ◽  
Combined System ◽  
Discrete Phase Modeling ◽  
Discrete Phase ◽  
Time Required ◽  
Heated Soil

Heated Soil Vapor Extraction (HSVE), developed by Advanced Remedial Technology is a Soil remediation process that has gained significant attention during the past few years. HSVE along with Air sparging has been found to be an effective way of remediating soil of various pollutants including solvents, fuels and Para-nuclear aromatics. The combined system consists of a heater/boiler that pumps and circulates hot oil through heating wells, a blower that helps to suck the contaminants out through the extraction well, and air sparging wells that extend down to the saturated region in the soil. Both the heating wells and extraction wells are installed vertically in the saturated region in contaminated soil and is welded at the bottom and capped at the top. The heat source heats the soil and the heat is transported inside the soil by means of conduction and convection. This heating of soil results in vaporization of the gases, which are then absorbed by the extraction well. Soil vapor extraction cannot remove contaminants in the saturated zone of the soil that lies below the water table. In that case air sparging may be used. In air sparging system, air is pumped into the saturated zone to help flush the contaminants up into the unsaturated zone where the contaminants are removed by SVE well. In this analysis an attempt has been made to predict the behavior of different chemicals in the unsaturated and saturated regions of the soil. This analysis uses the species transport and discrete phase modeling to predict the behavior of different chemicals when it is heated and absorbed by the extraction well. Such an analysis will be helpful in predicting the parameters like the distance between the heating and extraction wells, the temperature to be maintained at the heating well and the time required for removing the contaminants from the soil.

Upscaling Study of Vapor Extraction Process Through Numerical Simulation

2012 ◽  
Vol 95 (3) ◽  
pp. 697-715 ◽  
Author(s):  
S. Xu ◽  
F. Zeng ◽  
Y. Gu ◽  
K. D. Knorr
Keyword(s):  
Numerical Simulation ◽  
Extraction Process ◽  
Vapor Extraction

Revisiting the Butler-Mokrys Model for the Vapor-Extraction Process

SPE Journal ◽  
2019 ◽  
Vol 24 (02) ◽  
pp. 511-521
Author(s):  
V.. Mohan ◽  
P.. Neogi ◽  
B.. Bai
Keyword(s):  
Concentration Profile ◽  
Heavy Oil ◽  
Extraction Process ◽  
Previous Model ◽  
Oil Reservoir ◽  
Vapor Extraction ◽  
Oil Viscosity ◽  
Solvent Vapor ◽  
Vapor Interface ◽  
Heavy Oil Reservoir

Summary The dynamics of a process in which a solvent in the form of a vapor or gas is introduced in a heavy-oil reservoir is considered. The process is called the solvent vapor-extraction process (VAPEX). When the vapor dissolves in the oil, it reduces its viscosity, allowing oil to flow under gravity and be collected at the bottom producer well. The conservation-of-species equation is analyzed to obtain a more-appropriate equation that differentiates between the velocity within the oil and the velocity at the interface, which can be solved to obtain a concentration profile of the solvent in oil. We diverge from an earlier model in which the concentration profile is assumed. However, the final result provides the rate at which oil is collected, which agrees with the previous model in that it is proportional to h, where h is the pay-zone height; in contrast, some of the later data show a dependence on h. Improved velocity profiles can capture this dependence. A dramatic increase in output is seen if the oil viscosity decreases in the presence of the solvent, although the penetration of the solvent into the oil is reduced because under such conditions the diffusivity decreases with decreased solvent. One other important feature we observe is that when the viscosity-reducing effect is very large, the recovered fluid is mainly solvent. Apparently, some optimum might exist in the solubility φo, where the ratio of oil recovered to solvent lost is the largest. Finally, the present approach also allows us to show how the oil/vapor interface evolves with time.

To improve the Recovery of an Arab Stemmer for Information Retrieval

2018 ◽  
Vol 10 (1) ◽  
pp. 25-33
Author(s):  
Khaireddine Bacha
Keyword(s):  
Information Retrieval ◽  
Error Rate ◽  
Automatic Processing ◽  
Arabic Language ◽  
Extraction Process ◽  
Finite State Automata ◽  
New Approach ◽  
Root Extraction ◽  
Finite State

The automatic processing of the Arabic language is a growing discipline, in which one sees more and more research and technologies to examine the specificities of this language and to propose tools necessary to the development of its automatic processing. The old techniques of rooting have limits that weaken the process of root extraction. In this article, the author proposes a new approach to rooting based on two finite state automata. The technique proposed is based on finite state automata in the root extraction process, with the aim of minimizing the error rate and ambiguity, usually due to the removal of the affixes. The author is currently focusing on the development and improvement of the rooting technique while trying to overcome the various problems encountered. The author is working on the compilation of a corpus of evaluation which will allow him to evaluate and compare their approach to others

Turbulent Wall-Pressure Fluctuations: A New Model for Off-Axis Cross-Spectral Density

1997 ◽  
Vol 119 (2) ◽  
pp. 277-280 ◽  
Author(s):  
B. A. Singer
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Spectral Density ◽  
Flow Direction ◽  
Wall Pressure ◽  
Mean Flow ◽  
New Approach ◽  
Cross Spectral Density ◽  
The Mean ◽  
The Cross

Models for the distribution of the wall-pressure under a turbulent boundary layer often estimate the coherence of the cross-spectral density in terms of a product of two coherence functions. One such function describes the coherence as a function of separation distance in the mean-flow direction, the other function describes the coherence in the cross-stream direction. Analysis of data from a large-eddy simulation of a turbulent boundary layer reveals that this approximation dramatically underpredicts the coherence for separation directions that are neither aligned with nor perpendicular to the mean-flow direction. These models fail even when the coherence functions in the directions parallel and perpendicular to the mean flow are known exactly. A new approach for combining the parallel and perpendicular coherence functions is presented. The new approach results in vastly improved approximations for the coherence.

scholarly journals Fine particle pH and sensitivity to NH<sub>3</sub> and HNO<sub>3</sub> over summertime South Korea during KORUS-AQ

2020 ◽  
Author(s):  
Ifayoyinsola Ibikunle ◽  
Andreas Beyersdorf ◽  
Pedro Campuzano-Jost ◽  
Chelsea Corr ◽  
John D. Crounse ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Deposition Velocity ◽  
Liquid Water Content ◽  
Aerosol Formation ◽  
Aerosol Composition ◽  
New Approach ◽  
South Korean ◽  
Inorganic Nitrate ◽  
Nitrate Availability ◽  
Trace Species

Abstract. Using a new approach that constrains thermodynamic modeling of aerosol composition with measured gas-to-particle partitioning of inorganic nitrate, we estimate the acidity levels for aerosol sampled in the South Korean planetary boundary layer during the NASA/NIER KORUS-AQ field campaign. The pH (mean ± 1σ = 2.43 ± 0.68) and aerosol liquid water content determined were then used to determine the chemical regime of the inorganic fraction of particulate matter (PM) sensitivity to ammonia and nitrate availability. We found that the aerosol formation is always sensitive to HNO3 levels, especially in highly polluted regions, while it is only exclusively sensitive to NH3 in some rural/remote regions. Nitrate levels are further promoted because dry deposition velocity is low and allows its accumulation in the boundary layer. Because of this, HNO3 reductions achieved by NOx controls prove to be the most effective approach for all conditions examined, and that NH3 emissions can only partially affect PM reduction for the specific season and region. Despite the benefits of controlling PM formation to reduce ammonium-nitrate aerosol and PM mass, changes in the acidity domain can significantly affect other processes and sources of aerosol toxicity (such as e.g., solubilization of Fe, Cu and other metals) as well as the deposition patterns of these trace species and reactive nitrate.

Application of Boundary-Layer Theory in Turbomachinery

1959 ◽  
Vol 81 (4) ◽  
pp. 543-551 ◽  
Author(s):  
H. Schlichting
Keyword(s):  
Boundary Layer ◽  
Experimental Study ◽  
Boundary Layer Theory ◽  
New Approach

Some of the results of a new approach to a theoretical and experimental study of flows through cascades.

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