A Three-Dimensional Three-Phase Model of Gas Injection in AOD Converters

2013 ◽  
Vol 85 (3) ◽  
pp. 376-387 ◽  
Author(s):  
Anders Tilliander ◽  
Lage T. I. Jonsson ◽  
Pär G. Jönsson
Keyword(s):  
Gas Injection ◽  
Three Dimensional ◽  
Phase Model ◽  
Three Phase

An Analysis for Simulating Reservoir Performance Under Pressure Maintenance by Gas and/or Water Injection

1968 ◽  
Vol 8 (04) ◽  
pp. 331-340 ◽  
Author(s):  
K.H. Coats
Keyword(s):  
Gas Injection ◽  
Water Injection ◽  
Three Dimensional ◽  
Three Dimensional Flow ◽  
Gas Density ◽  
Flow Equations ◽  
Flow Problems ◽  
Dimensional Flow ◽  
Three Phase ◽  
Compressibility Effects

Coats, K.H., Member AIME, The U. of Texas, Austin, Texas Abstract This paper describes a generalized analysis for calculating three-phase, three-dimensional flow in reservoirs. The analysis handles pressure maintenance type problems where fluid compressibility effects are negligible. A separate analysis for depletion type problems is described in another paper. The calculations consist of numerical, simultaneous solution of the three-flow equations using the iterative alternating direction technique of Douglas and Rachford. The mathematical details are fully described in the Appendix. The analysis is a computerized mathematical model that accounts for gravity, and capillary and viscous forces, and allows arbitrary reservoir heterogeneity, geometry, well locations and rates. A unique aspect of the analysis is the simultaneous solution of only as many difference equations in each grid block of the reservoir as there are mobile phases present. Thus, while the analysis handles phases present. Thus, while the analysis handles three-phase flow, the efficiency of the calculations (in a typical problem where three phases actually coexist only in a minor portion of the reservoir) is four to eight times greater than that of an analysis solving three equations in every block. The program may be applied to two-phase flow problems and to one-, two- or three-dimensional flow problems with negligible loss in efficiency, compared to programs specifically written for these sub cases. This paper also describes several applications of the analysis which illustrate some effects of gravitational and capillary forces in waterflooding of a heterogeneous reservoir. Another application indicates the utility of the program in simulating the fillup stage of water injection into a reservoir containing an initial free gas phase. Computer times and costs for the applications performed are given to indicate the current expense performed are given to indicate the current expense of three-dimensional, three-phase reservoir simulation. Introduction Under pressure maintenance by water and/or gas injection, fluid compressibility effects are generally negligible in producing operations. Although gas compressibility may be appreciable, the maintenance of pressure results in negligible time variation of gas density. In addition, the spatial variation of gas density is usually small in relation to the gas density itself. Producing schemes of pattern or flank waterflood and/or crestal gas injection, therefore, may be simulated with an analysis which presumes fluid incompressibility. presumes fluid incompressibility. The computing efficiency of a numerical model for simulating incompressible fluid flow is as much as 50 percent greater than that of a compressible flow model. Therefore, an analysis for numerically simulating three-dimensional flow of three incompressible, immiscible phases was developed and programmed. programmed. THE MODEL The equations describing three-phase, incompressible flow are the continuity equation and Darcy's law for each flowing phase. Combining these equations and introducing capillary pressures gives the three flow equations: ................ (1a) ............... (1b) SPEJ p. 331

Transport of organochlorine pesticides in soil columns enhanced by dissolved organic carbon

1997 ◽  
Vol 35 (7) ◽  
pp. 139-145 ◽  
Author(s):  
Jiann-Yuan Ding ◽  
Shian-Chee Wu
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Organochlorine Pesticides ◽  
Transport Model ◽  
Phase Model ◽  
Soil Columns ◽  
Two Phase ◽  
Three Phase ◽  
Phase Transport ◽  
Remediation Of Soil

The objective of this study is to quantify the effects of humic acid solution infiltration on the transport of organochlorine pesticides (OCPs) in soil columns using a three-phase transport model. From experimental results, it is found that the dissolved organic carbon enhances the transport of OCPs in the soil columns. In the OCPs-only column, the concentration profiles of OCPs can be simulated well using a two-phase transport model with numerical method or analytical solution. In the OCPs-DOC column, the migrations of aldrin, DDT and its daughter compounds are faster than those in the OCPs-only column. The simulation with the three-phase model is more accurate than that with the two-phase model. In addition, significant decrease of the fluid pore velocities of the OCPs-DOC column was found. When DOC leachate is applied for remediation of soil or groundwater pollution, the decrease of mean pore velocities will be a crucial affecting factor.

scholarly journals Autocratisation by Term Limits Manipulation in Sub-Saharan Africa

2020 ◽  
Vol 55 (3) ◽  
pp. 228-250 ◽  
Author(s):  
Andrea Cassani
Keyword(s):  
Comparative Studies ◽  
Political Competition ◽  
Chief Executive ◽  
Term Limits ◽  
Sub Saharan Africa ◽  
Phase Model ◽  
Econometric Modelling ◽  
Three Phase ◽  
Sub Saharan ◽  
Personal Rule

Besides the introduction of multi-party elections, the sub-Saharan wave of democratic reforms of the 1990s encompassed the introduction of limits to the number of terms that a chief executive can serve. Executive term limits (ETLs) are key for democracy to advance in a continent with a legacy of personal rule. However, the manipulation of ETLs has become a recurring mode of autocratisation, through which African aspiring over-stayers weaken executive constraints, taint political competition, and limit citizens’ possibility to choose who governs. This article presents a three-phase model of autocratisation by ETL manipulation and, using new data, offers one of the first regional comparative studies of ETL manipulation in sub-Saharan Africa that rests on econometric modelling. The analysis leads to revisiting some previous findings on the drivers of ETL manipulation and highlights the relevance of other previously underestimated factors that may either discourage a leader from challenging ETLs or prevent their successful manipulation.

scholarly journals A Three-Phase Fundamental Diagram from Three-Dimensional Traffic Data

Axioms ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 17
Author(s):  
Maria Laura Delle Delle Monache ◽  
Karen Chi ◽  
Yong Chen ◽  
Paola Goatin ◽  
Ke Han ◽  
...  
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Time Estimation ◽  
Travel Time Estimation ◽  
Traffic Data ◽  
Fundamental Diagram ◽  
Model Based Clustering ◽  
Three Phase ◽  
Characterization Of Solutions ◽  
Two Phases

This paper uses empirical traffic data collected from three locations in Europe and the US to reveal a three-phase fundamental diagram with two phases located in the uncongested regime. Model-based clustering, hypothesis testing and regression analyses are applied to the speed–flow–occupancy relationship represented in the three-dimensional space to rigorously validate the three phases and identify their gaps. The finding is consistent across the aforementioned different geographical locations. Accordingly, we propose a three-phase macroscopic traffic flow model and a characterization of solutions to the Riemann problems. This work identifies critical structures in the fundamental diagram that are typically ignored in first- and higher-order models and could significantly impact travel time estimation on highways.

Mixed potential type YSZ-based NO2 sensors with efficient three-dimensional three-phase boundary processed by electrospinning

2022 ◽  
Vol 354 ◽  
pp. 131219
Author(s):  
Siyuan Lv ◽  
Yueying Zhang ◽  
Li Jiang ◽  
Lianjing Zhao ◽  
Jing Wang ◽  
...  
Keyword(s):  
Phase Boundary ◽  
Three Dimensional ◽  
Mixed Potential ◽  
Potential Type ◽  
Three Phase ◽  
Three Phase Boundary
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