Oil Containment by Floating Boom under Wave-Current Coupling Condition II: Containment Failure

2013 ◽  
Vol 734-737 ◽  
pp. 1420-1424
Author(s):  
Qing Gong Zheng ◽  
Xing Feng ◽  
Wan Qing Wu
Keyword(s):  
Companion Paper ◽  
Coupling Condition ◽  
Experimental Platform ◽  
Wave Parameters ◽  
Current Coupling ◽  
Oil Density ◽  
The Relationship

The numerical experimental platform of oil containment by floating boom under combined wave and current conditions was presented in a companion paper. The present paper focuses on the application of the platform that numerically predicts the relationship between oil containment failure velocity and wave parameters, oil parameters and boom drafts. The effects of oil density and wave parameters on oil containment failure velocity receive particular attention, and the influence of other parameters such as initial oil volume and boom draft are also quantified.

Oil Containment by Floating Boom under Wave-Current Coupling Conditions III: Prediction on Failure Velocity

2014 ◽  
Vol 955-959 ◽  
pp. 1491-1495
Author(s):  
Xing Feng ◽  
Wan Qing Wu ◽  
Gui Feng Yu
Keyword(s):  
Numerical Simulation ◽  
Companion Paper ◽  
Experimental Platform ◽  
Oil Boom ◽  
Coupling Conditions ◽  
Wave Parameters ◽  
Oil Spill Response ◽  
Current Coupling ◽  
Oil Density ◽  
Detailed Derivation

The numerical simulation of oil containment by floating boom under wave-current coupling conditions is presented in a companion paper. The present paper focuses on the use of the numerical experimental platform developed by FENG and WU for the prediction of oil containment failure velocity of floating boom under wave-current coupling conditions. Detailed derivation processes about the containment failure velocity formula are provided. The effects of oil parameters, wave parameters and oil boom parameters on oil containment failure velocity receive particular attention, and the influences of some of these parameters such as oil density, boom draft are quantified. The prediction model can provide an economic, convenient method for oil spill response.

Oil Containment by Floating Boom under Wave-Current Coupling Condition I: Numerical Experimental Platform

2013 ◽  
Vol 734-737 ◽  
pp. 1209-1212 ◽  
Author(s):  
Xing Feng ◽  
Qing Gong Zheng ◽  
Wan Qing Wu
Keyword(s):  
Stokes Equations ◽  
Viscous Incompressible Fluid ◽  
Navier Stokes ◽  
Constant Depth ◽  
Coupling Condition ◽  
Navier Stokes Equations ◽  
Experimental Platform ◽  
Vof Model ◽  
Current Coupling ◽  
Counter Current

Based on the Navier-Stokes equations for viscous, incompressible fluid and analytic relaxation approach, the 2-D numerical wave and current tank of the viscous fluid with constant depth is established, the volume of fluid (VOF) model is used to track the free surface for simulating the oil containment by rigid floating boom under wave and current conditions, and the motion of boom is accomplished by the technique of dynamic mesh. Then the variation of the oil shape under pure current condition, coplanar current condition and counter current condition were numerically studied, the effects of wave parameters on oil shape before boom were analyzed. The computed results are in general agreement with those obtained from previous studies.

scholarly journals Study on the Relationship between Electrical Tree Development and Partial Discharge of XLPE Cables

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Chaofei Gao ◽  
Yanlong Yu ◽  
Zan Wang ◽  
Wei Wang ◽  
Liwei Zheng ◽  
...  
Keyword(s):  
Statistical Characteristics ◽  
Time Frequency ◽  
Experimental Platform ◽  
Equivalent Time ◽  
Electrical Tree ◽  
Electrical Trees ◽  
Insulation Breakdown ◽  
The Relationship ◽  
Frequency Diagram ◽  
Tree Development

Based on the slice materials of 35 kV and 110 kV XLPE cables, an experimental platform is built to study the relationship between electrical tree and PDs in XLPE with different voltage levels. There are three significant statistical characteristics of the PDs during the growth of electrical trees. The analysis of the results shows that each growth stage has certain characteristics. Different features existed between the growth of the electrical trees and the PD in the insulation of the 35 and 110 kV cables. Evident characteristics such as large spans of time and frequency were present as the electrical trees grew violently in the equivalent time-frequency diagram at every stage. These results could provide criteria for the identification of the deterioration using PD to monitor cables in service at rated voltages. The results are important for the identification of defects in cable insulation in order to provide an early warning of insulation breakdown in the cables.

scholarly journals The Relationship between Equatorial Mixed Rossby–Gravity and Eastward Inertio-Gravity Waves. Part II

2016 ◽  
Vol 73 (5) ◽  
pp. 2147-2163 ◽  
Author(s):  
Juliana Dias ◽  
George N. Kiladis
Keyword(s):  
Pacific Ocean ◽  
Gravity Waves ◽  
Companion Paper ◽  
Empirical Orthogonal Functions ◽  
Central Pacific ◽  
The West ◽  
Orthogonal Functions ◽  
Central Pacific Ocean ◽  
The Relationship ◽  
Zonal Propagation

Abstract Space–time spectral analysis of tropical cloudiness data shows strong evidence that convectively coupled n = 0 mixed Rossby–gravity waves (MRGs) and eastward inertio-gravity waves (EIGs) occur primarily within the western/central Pacific Ocean. Spectral filtering also shows that MRG and EIG cloudiness patterns are antisymmetric with respect to the equator, and they propagate coherently toward the west and east, respectively, with periods between 3 and 5 days, in agreement with Matsuno’s linear shallow-water theory. In contrast to the spectral approach, in a companion paper it has been shown that empirical orthogonal functions (EOFs) of 2–6-day-filtered cloudiness data within the tropical Pacific Ocean also suggest an antisymmetric pattern, but with the leading EOFs implying a zonally standing but poleward-propagating oscillation, along with the associated tropospheric flow moving to the west. In the present paper, these two views are reconciled by applying an independent approach based on a tracking method to assess tropical convection organization. It is shown that, on average, two-thirds of MRG and EIG events develop independently of one another, and one-third of the events overlap in space and time. This analysis also verifies that MRG and EIG cloudiness fields tend to propagate meridionally away from the equator. It is demonstrated that the lack of zonal propagation implied from the EOF analysis is likely due to the interference between eastward- and westward-propagating disturbances. In addition, it is shown that the westward-propagating circulation associated with the leading EOF is consistent with the expected theoretical behavior of an interference between MRGs and EIGs.

scholarly journals EVALUATING THE DEGREE OF COMPLEXITY OF TIGHT OIL RECOVERY BASED ON THE CLASSIFICATION OF OILS

2020 ◽  
pp. 76-81
Author(s):  
G. Efendiyev ◽  
M. Karazhanova ◽  
D. Akhmetov ◽  
I. Piriverdiyev
Keyword(s):  
Cluster Analysis ◽  
Oil Recovery ◽  
Fuzzy Cluster ◽  
Fuzzy Cluster Analysis ◽  
Recovery Coefficient ◽  
Reservoir Permeability ◽  
Oil Density ◽  
The Relationship ◽  
Degree Of Recovery

The article discusses the results of the use of cluster analysis in assessing the degree of oil recovery complexity and its impact on the performance indicator. For this purpose, clustering was performed using a fuzzy cluster analysis algorithm. It should be noted that along with the deposits of heavy and highly viscous oils, a large share of hard-to-recover reserves is also confined to conditions with very low reservoir permeability values. Data on viscosity, oil density and oil permeability of in-situ conditions from various fields of Kazakhstan are collected. Using the results of this classification, a statistical analysis of indicators of various types of hard-torecover oils was performed. In the process of analysis, a generalized characteristic was determined for each class of oil, including viscosity, oil density and reservoir permeability. The generic characteristic is a linear transformation of the three characteristics. The results were subjected to statistical processing. At the same time, an attempt was made to establish and analyze the relationship between the degree of recovery complexity of hard-to-recover oils and oil recovery coefficient. In the course of the analysis, the average values of the oil recovery coefficient and the index of the degree of recovery complexity of hard-to-recover oil within each cluster were calculated and the relationship between them was plotted. The observed dependence, built on averaged points, is close to a power law, and, as one would expect, with an increase in the degree of oil recovery complexity, the oil recovery coefficient falls. The obtained estimates of the degree of oil recovery complexity allow us to rank different types of oils by their viscosity, density and reservoir permeability, which can be used to compare types of hard-to-recover oils by the value of the quality indicator. Methods to solve the problem of hard-to-remove high-viscosity and heavy oils should be aimed at reducing the viscosity of oil in the reservoir: injection of hot water / steam into the reservoir, the use of electric heaters, etc. Purpose. Assessment of the degree of oil recovery complexity and its impact on the efficiency of field development. The technique. The solution of the tasks set in the work was carried out on the method of mathematical statistics and the theory of fuzzy sets. In this case, the methods of processing the results, the correlation analysis, and the algorithm of fuzzy cluster analysis were used. Results. As a result of studies, 4 classes were obtained, each of which characterizes the degree of oil recovery complexity, a parameter was proposed for quantifying the degree of complexity, including oil density and viscosity, reservoir permeability, a relationship between this parameter and oil recovery coefficient was obtained. Scientific novelty. A classification of hard-to-recover reserves based on a fuzzy cluster analysis has been performed, and a parameter has been proposed for quantifying the degree of oil recovery complexity, a relationship has been obtained that allows judging the oil recovery by the degree of oil recovery complexity. Practical significance. The results obtained make it possible to classify hard-to-recover reserves and make decisions on the choice of methods for influencing the reservoir in various geological conditions.

Research on the Experimental Platform of Ground Source Heat Pump

2013 ◽  
Vol 838-841 ◽  
pp. 1944-1948
Author(s):  
Zhao Kang Xu ◽  
Dao Lai Cheng ◽  
Bo Wang
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Research Result ◽  
Ground Source Heat Pump ◽  
Experimental Platform ◽  
Environmental Friendly ◽  
Ground Source ◽  
Consumption Data ◽  
The Relationship ◽  
Multiple Conditions

The ground source heat pump technology has been maturing. However, related project designs are mostly following intuitive experience data, and are lack of the relationship between qualification in theory and quantitation in practice. To address this issue, this platform is devised for experimental research. Using this experimental platform, one can adjust for multiple conditions in one season, continuously record energy consumption data, and determine which mode has the best effect and lower energy consumption. Based on the experimental data, the analysis and research result can be referred by practical devising of the projects, and establish the relationship between qualification in theory and quantitation in practice, making the ground source heat pump be more energy-saving, economical and environmental friendly.

Decoupling between Construction Land Change and GDP Growth in China

2013 ◽  
Vol 850-851 ◽  
pp. 1343-1346 ◽  
Author(s):  
Xiao Fan Zhao ◽  
Li Xu
Keyword(s):  
Continuous Distribution ◽  
Major Change ◽  
Gdp Growth ◽  
Land Change ◽  
National Scale ◽  
Coupling Condition ◽  
Construction Land ◽  
Change Trend ◽  
Spatio Temporal ◽  
The Relationship

In order to analyze the relationship between urban construction land and economic development, and to know the similarities and differences of the relationship in different province in China, decoupling theory was introduced to analysis the relationship between construction land change and GDP growth. Research showed that, during 2003-2008, spatio-temporal difference was existed in every province in China about decoupling and coupling degree between construction land change and GDP changes. At the same time, there was also the leading type or major change trend. (1) During the 2003-2008, from the national scale, the interaction between construction change and GDP growth varied from weak decoupling state to the weak coupling condition. (2) Decoupling degree between construction change and GDP growth has a little difference in each provincial region in China, which showed majority continuous distribution in space. (3) Decoupling process between construction land and GDP growth may be turn into opposite direction, and the process was tortuous.

scholarly journals The universal aspect ratio of vortices in rotating stratified flows: experiments and observations

2012 ◽  
Vol 706 ◽  
pp. 34-45 ◽  
Author(s):  
Oriane Aubert ◽  
Michael Le Bars ◽  
Patrice Le Gal ◽  
Philip S. Marcus
Keyword(s):  
Aspect Ratio ◽  
Salt Water ◽  
Boussinesq Equations ◽  
Companion Paper ◽  
Buoyancy Frequency ◽  
Coriolis Parameter ◽  
Aspect Ratios ◽  
Horizontal Length ◽  
The Law ◽  
The Relationship

AbstractWe validate a new law for the aspect ratio $\ensuremath{\alpha} = H/ L$ of vortices in a rotating, stratified flow, where $H$ and $L$ are the vertical half-height and horizontal length scale of the vortices. The aspect ratio depends not only on the Coriolis parameter $f$ and buoyancy (or Brunt–Väisälä) frequency $\bar {N} $ of the background flow, but also on the buoyancy frequency ${N}_{c} $ within the vortex and on the Rossby number $\mathit{Ro}$ of the vortex, such that $\ensuremath{\alpha} = f \mathop{ [\mathit{Ro}(1+ \mathit{Ro})/ ({ N}_{c}^{2} \ensuremath{-} {\bar {N} }^{2} )] }\nolimits ^{1/ 2} $. This law for $\ensuremath{\alpha} $ is obeyed precisely by the exact equilibrium solution of the inviscid Boussinesq equations that we show to be a useful model of our laboratory vortices. The law is valid for both cyclones and anticyclones. Our anticyclones are generated by injecting fluid into a rotating tank filled with linearly stratified salt water. In one set of experiments, the vortices viscously decay while obeying our law for $\ensuremath{\alpha} $, which decreases over time. In a second set of experiments, the vortices are sustained by a slow continuous injection. They evolve more slowly and have larger $\vert \mathit{Ro}\vert $ while still obeying our law for $\ensuremath{\alpha} $. The law for $\ensuremath{\alpha} $ is not only validated by our experiments, but is also shown to be consistent with observations of the aspect ratios of Atlantic meddies and Jupiter’s Great Red Spot and Oval BA. The relationship for $\ensuremath{\alpha} $ is derived and examined numerically in a companion paper by Hassanzadeh, Marcus & Le Gal (J. Fluid Mech., vol. 706, 2012, pp. 46–57).

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