Bibliographies: 'Annual flow' – Grafiati (2024)

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Dams have major impacts on river hydrology with a general tendency to decrease annual maximum flows and increase annual minimum flows. The analysis of 41 streamflow series in California, USA are examined, and the results show that, as expected, the mean values and variations of annual peak flows and maximum flows of different durations are reduced for almost all sites after dam use, and the larger the ratio of total reservoir capacity to pre-dam annual runoff, the larger the rate of peak flow reduction. However, the impacts on minimum flow are mixed. For five out of seven cases with long data records for periods before and after dam use, the average annual minimum flow as well as its variation increased, but for the other two cases, they decreased. No significant changes are detected for various extreme precipitation indices; therefore, dam construction is believed to be the major reason for flow regime changes. The probability distribution of extreme flows also changed, due to the impacts of dams. The Log-Pearson Type III (LP3) distribution is best for peak flow series and one-day maximum series at sites with or without the impact of dams; the three-parameter Weibull (W3) distribution is the best model for the seven-day minimum flow at sites with no or minor dam impacts, whereas at sites with major dam impacts, the best model is the generalized extreme value (GEV) model for the seven-day minimum flow.

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Abstract. The article is devoted to the analysis of long-term fluctuations of the annual flow of the Shirvan rivers. The analysis used data from 4 rivers with an observation period of more than 50 years. linear trends were identified in the observation series, and their significance was assessed. The annual water discharge observations are divided into two series, covering 1961-1990 and 1991-2018. The dynamics of annual precipitation data of meteorological observation stations located in the study area were also analyzed. Annual precipitation increased in Goychay and Ismayilli meteorological stations, and partial decrease in Gabala and Oguz meteorological stations. The seasonal variation of the annual flow is also analyzed. According to data of Alijanchay and Girdimanchay, a decrease in annual flow was observed, and an increase was observed in Goychay and Turyanchay rivers. The seasonal fluctuations of the flow increased in the cold seasons and decreased in the warm seasons. Keywords: annual flow, long-term fluctuations, linear trends, climate changes

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AbstractA flow duration curve (FDC) plots the percentage of time that flow in a stream is equal to or exceeding a given value. In a gauged basin, it is obtained by sorting the observed flow from the largest to the smallest, and plotting against the corresponding exceedance probability. At ungauged basins where no data exist, the need for developing empirical methods emerges. This study aims at developing an FDC model for ungauged basins. The model is based on the normalized nondimensional annual mean flow quantiles. The annual mean flow is empirically calculated by a regression equation that takes drainage area and annual precipitation as input. Slope of the channel is additionally considered in the regression, however no better performance is achieved. Seyhan and Ceyhan basins in the Mediterranean region in southern Turkey are chosen as the study area. Data from 109 gauging stations are used for the calibration and validation of the model. Gauging stations on the tributaries are studied with a view to limiting anthropogenic activities on the rivers. Results of the application are found so promising that the model can be considered a good foundation for the development of FDCs at ungauged basins.

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Environmental flow assessments (e-flows) are relatively new practices, especially in developing countries such as Nepal. This study presents a comprehensive analysis of the influence of hydrologically based e-flow methods in the natural flow regime. The study used different hydrological-based methods, namely, the Global Environmental Flow Calculator, the Tennant method, the flow duration curve method, the dynamic method, the mean annual flow method, and the annual distribution method to allocate e-flows in the Kaligandaki River. The most common practice for setting e-flows consists of allocating a specific percentage of mean annual flow or portion of flow derived from specific percentiles of the flow duration curve. However, e-flow releases should mimic the river’s intra-annual variability to meet the specific ecological function at different river trophic levels and in different periods over a year covering biotas life stages. The suitability of the methods was analyzed using the Indicators of Hydrological Alterations and e-flows components. The annual distribution method and the 30%Q-D (30% of daily discharge) methods showed a low alteration at the five global indexes for each group of Indicators of Hydrological Alterations and e-flows components, which allowed us to conclude that these methods are superior to the other methods. Hence, the study results concluded that 30%Q-D and annual distribution methods are more suitable for the e-flows implementation to meet the riverine ecosystem’s annual dynamic demand to maintain the river’s health. This case study can be used as a guideline to allocate e-flows in the Kaligandaki River, particularly for small hydropower plants.

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The Don River Long near Razdorskaya Village had long phases (lasting 33–86 years) of increased/decreased naturalized annual and seasonal water flow, and their properties for 1891–2019 were identified. Long-term changes in the annual and snow-melt flood flow occurred in the opposite phase relative to changes in the winter and summer-autumn flow. Annual hydrographs in the phase of decreased flow were characterized by an increase in water discharge during the low-water seasons of the year, but a noticeable decrease in daily flood water discharge and maximum water discharge. The share of high-water years (years with a flow exceedance probability equal to or less than 25%) in the phase of increased flow is significantly higher than the share of low-water years (years with a flow exceedance probability equal to or more than 75%). And on the contrary. At the same time the cumulative share of low- and high-water years remains relatively stable. The total changes in the annual and seasonal flow, caused by both anthropogenic and climatic factors, throughout the entire period of modern global warming (since 1989) consisted in a decrease of the annual and snow-melt flood flow and an increase of flow values during low-water seasons.

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Abstract. With growing water needs for food production, it is necessary to improve the quantification of "Environmental Flow Requirements (EFRs)" to secure enough water for the freshwater ecosystems. In this study, five methods for calculating EFRs were compared to 11 case studies of locally-calculated EFRs. Three of the methods already existed (Smakhtin, Tennant and Tessmann) and two were developed in this study (the Variable Monthly Flow method and the Q90_Q50 method). The Variable Monthly Flow (VFM) method mimics for the first time the natural flow regimes while being "validated" at global and local scales. The VFM uses algorithms to classify flow regime into high, intermediate and low-flow months to take into account intra-annual variability by allocating EFRs with a percentage of mean monthly flow (MMF). The Q90_Q50 method allocates annual flow quantiles (Q50 and Q90) depending on the flow season. The results showed that, over all methods, 37% of annual discharge was allocated to "Nature" with a higher pressure on low flow requirements (LFR = 46% to 71% of average low flows) than on high flow requirements (HFR = 17% to 45% of average high flows). Environmental flow methods using fixed annual thresholds such as Tennant, Q90_Q50 and Smakhtin seemed to overestimate EFRs of stable flow regimes and underestimate EFRs of variable flow regimes. VFM and Tessmann methods showed the highest correlation with the locally-calculated EFRs (R2 = 0.91). The main difference between the Tessmann and VFM methods is that Tessmann method does not allow any water withdrawals during the low-flow season. Those five methods were tested within the global vegetation and hydrological model LPJml. The calculated global annual EFRs for "fair" ecological conditions represent between 25 to 46% of mean annual flow (MAF). Variable flow regimes such as the Nile have lower EFRs (ranging from 12 to 48% of MAF) than stable tropical regimes such as the Amazon (EFRs ranging from 30 to 67% of MAF).

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1.Higher Mathematics: manual. Theory of Probability and Elements of Mathematical Statistics / V.P. Denisiuk, V.M. Bobkov, L.A. Grishina – K.: NAU, 2013. 210-216 pages.2.Пасажиропотік аеропортів України [Electronic source] - https://www.wikiwand.com/uk/Пасажиропотік_аеропортів_України/Загальний_пасажиропотік_аеропортів_України.3.Валовой внутренний продукт (ВВП) в Украине 2021[Electronic source] -https://index.minfin.com.ua/economy/gdp/
In many problems of physics, economics, medicine, engineering, etc. we have to experimentally study the dependence of a random variable Y, observed, on one or more other random or non-random variables Х_1,Х_2,…,Х_n. Regression analysis is a branch of mathematical statistics that studies the dependence between random variables using regression equations, and regression is the functional dependence on average of any random variables.

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Prediction of flow is necessary for planning and management of water resources. The objective of this study is to estimate mean annual flows for the USA and mean monthly flows for the rivers of central Texas based on the precipitation and their watershed characteristics. Flow varies largely with topographic and climatic parameters and hence generalization of runoff models is difficult. This model aims at providing a prediction at ungaged locations with very few parameters that are easily available and measurable. Scatter in predicted data will be seen at the annual and monthly time scale in the range selected for each data. This model will work on annual and monthly means to reduce the scatter and produce better estimates.

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Flow boiling in microchannels has received enormous interest over the past few decades because of its importance in the thermal management of micro-structured devices. Few of previously published studies focus specifically on microchannel annular flow boiling which is very important due to its prevalence in this system. This thesis provides understanding of the heat and mass transfer in microchannel annular flow boiling via the use of a computational fluid dynamics (CFD) approach. The commercial software ANSYS Fluent was chosen to perform the CFD simulations. A modified height function (HF) method was implemented into the default CSF model to improve the performance of surface tension modelling. Simulation of an inviscid parallel flow demonstrated successful prediction of the onset of Kelvin-Helmholtz (K-H) instability in close accord with the analytical criterion. Studies of imposed numerical perturbations in laminar annular air-water flow showed that viscosity does not affect the stability of interfacial waves but has large impacts on the growth rates. A phase change model was formulated using a kinetic-based model to calculate the interphase mass flux. An established numerical smoothing procedure was used to improve numerical stability. A detailed study of a laminar annular flow boiling was performed using water at 160 kPa in a 0.5 mm diameter channel with constant fluid mass flux G = 60 kg m−2 s−1 and inlet vapour quality x = 0.1. Interfacial waves were observed and flow recirculation and a localised increase of heat transfer coefficient occurred at the interfacial wave troughs, where the liquid film was very thin. A parametric analysis showed that boiling heat transfer coefficient increases with increasing mass flux, system pressure, vapour quality and heat flux but decreases with increasing tube diameter.

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Ce travail a eu pour but premier d’étudier le risque d’évolution de la résistance aux herbicides inhibiteurs de l’acétolactate synthase (ALS) chez l’ambroisie à feuilles d’armoise (Ambrosia artemisiifolia L.) à travers quatre points : (i) la pression de sélection (étude de l’efficacité d’une gamme d'herbicides inhibiteurs de l’ALS), (ii) la capacité de réponse adaptative de l’adventice (détermination de la variation de la sensibilité aux inhibiteurs de l’ALS entre plantes et mise en place d’un programme de sélection récurrente), (iii) une étude de terrain (recherche de résistance aux inhibiteurs de l’ALS au champ en France), (iv) l’étude des mécanismes de résistance (liée à la cible – RLC – et non liée à la cible – RNLC – par une approche de transcriptomique). Le second objectif fut d’étudier la connectivité des populations d’A. artemisiifolia dans des paysages agricoles à l’aide de marqueurs microsatellites développés lors de ce travail afin de déterminer les facteurs qui pourraient faciliter la dispersion de cette espèce et de la résistance à l’échelle du paysage agricole.En ce qui concerne la résistance aux herbicides :-La réponse de d’A. artemisiifolia aux herbicides inhibiteurs de l’ALS est très variable entre substances.-Des plantes ayant survécu à la dose maximale autorisée et à des doses supérieures de metsulfuron ont été sélectionnées pour débuter un programme de sélection récurrente. Après deux cycles de sélection, on observe une intensification de la résistance au metsulfuron et une émergence de la résistance à l’imazamox et au tribénuron.-Trois cas de résistance à l’imazamox ont été identifiés au champ dont deux cas de pure RNLC et un cas de coexistence RLC – RNLC.-Un transcriptome d’A. artemisiifolia a été généré grâce à la technique de séquençage PacBio pour rechercher des gènes impliqués dans les mécanismes de RNLC (approche RNAseq). 62 gènes candidats ont été identifiés dont des transporteurs ABC, des cytochromes P450 ainsi que des glutathione-S-transférases connus pour être impliqués dans la dégradation des herbicides.Pour l’étude de la connectivité des populations agricoles :-26 marqueurs microsatellites ont été développés et ont révélé une forte variabilité génétique. La structuration génétique a été étudiée à grande échelle pour des populations d’A. artemisiifolia d’Europe (aire d’invasion) et d’Amérique du Nord (aire d’origine).-À une échelle plus fine (paysage agricole), la structure génétique des populations reste influencée par les événements de colonisation. Les événements de migration qui ont été identifiés entre zones de présence de l’ambroisie suggèrent des flux de gènes (pollen/sem*nces) et une connectivité modérés à l’échelle d’un territoire agricole. Dans les environnements agricoles, la dispersion des allèles de résistance aux herbicides pourrait se faire facilement de proche en proche via les flux de pollen, et également à plus longue distance via des dispersions de graines. Les activités anthropiques jouent un rôle majeur dans la dispersion des sem*nces (machineries agricoles, lots de sem*nces contaminés…).-L’analyse du système de reproduction a confirmé que cette espèce est allogame ce qui entraîne des flux de gènes intra- et inter-populations importants.Les connaissances acquises au cours de ce travail pourront aider à développer des stratégies de contrôle mieux adaptées, pour lutter efficacement contre A. artemisiifolia afin de limiter son expansion, telles que :-Des stratégies de désherbage diversifiées : combinaison de lutte mécanique (dont faux semis) et chimique (diversification des modes d’action herbicides).-Un allongement et une diversification des rotations de cultures en favorisant des cultures d’hiver et/ou des cultures couvrantes et compétitrices.Ces connaissances pourront aussi être utilisées dans la lutte contre une autre espèce adventice du genre Ambrosia, Ambrosia trifida.Mots-clés (6) : Ambrosia artemisiifolia L., ambroisies, résistance aux herbicides
The first aim of this work was to investigate the risk for the evolution of resistance to acetolactate synthase inhibitor (ALS) herbicides in the common ragweed (Ambrosia artemisiifolia L.) through four points: (i) the selection pressure (effectiveness of a range of ALS inhibitor herbicides), (ii) the adaptive response of Ambrosia artemisiifolia (recurrent selection experiment), (iii) a resistance monitoring in fields in France, and (iv) the investigation of the mechanisms underlying herbicide resistance (target-site (TSR) and non-target-site resistance (NTSR) using transcriptomic analyses). The second aim was to study the connectivity of A. artemisiifolia populations in agricultural landscapes using microsatellite markers developed during this work, to determine factors that could facilitate the spread of this invasive weed species and the spread of herbicide resistance.In regards to herbicide resistance:-The sensitivity of A. artemisiifolia to ALS-inhibiting herbicides is variable between active ingredients.-Plants that survived the French maximum authorized field rate and higher rates of metsulfuron were selected to implement a recurrent breeding program. After two selection cycles, the resistance level to metsulfuron increased and resistance to imazamox and tribenuron emerged.-Three cases of imazamox resistance were identified in the field, including two cases of pure NTSR and one case of TSR - NTSR coexistence.-A transcriptome for A. artemisiifolia, AMBELbase, was generated using the PacBio sequencing technology to search for genes involved in NTSR mechanisms (RNAseq approach). 62 candidate contigs were identified including ABC transporters, cytochromes P450 and glutathione S-transferases known to be involved in the degradation of herbicides.In regards to population connectivity:-26 microsatellite markers were developed and revealed high genetic variability. Genetic structuring has been studied on a large scale for populations of A. artemisiifolia from Europe (invasion range) and North America (native range).-On a finer scale (agricultural landscape), the genetic structure of populations was influenced by colonization events. Migration events detected among the areas colonized by A. artemisiifolia suggested moderate pollen/seed flows and connectivity at the farmland scale. In agricultural environments, herbicide resistant alleles could be easily spread among neighbouring populations via pollen flow, and also at longer distances via seed dispersal. Human-related activities play a major role in the dispersal of seeds (agricultural machinery, contaminated seed lots, etc.).-The mating system analysis confirmed that A. artemisiifolia is an obligate outcrossing species which leads to important intra- and inter-population gene flow.The knowledge acquired during this work may help to foster the development of better management strategies to effectively control A. artemisiifolia to limit its spread, such as:-Diversified weed control strategies: combination of mechanical (including false-seed) and chemical weeding (diversification of herbicide modes of action).-Longer diversified crop rotations including more winter crops and/or cover and competitive crops to break the life cycle of A. artemisiifolia.These knowledge may also be used to better control of another weed species of the genus Ambrosia, Ambrosia trifida L

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In the international oil and gas industry multiphase annular flow in pipelines and wells is extremely important, but not well understood. This thesis reports the development of an efficient and cheap method for measuring the phase flow rates in two phase annular and annular mist flow, in which the liquid phase is electrically conducting, using ultrasonic and conductance techniques. The method measures changes in the conductance of the liquid film formed during annular flow and uses these to calculate the volumetric and mass flow rates of the liquid film. The gas velocity in the core of the annular flow is measured using an ultrasonic technique. Combined with an entrainment model and the liquid film measurements described above, the ultrasonic technique enables the volumetric flow rate of the gas in the core and the volumetric and mass flow rates of entrained liquid droplets to be measured. This study was based on experimental work and the use of modelling techniques. The practical investigation comprised a series of experiments conducted on a purpose built flow loop in which the test section was a Perspex pipe of 50mm ID. The experimental work was limited to two-phase air-water flow. The flow loop was specifically designed to accommodate the different instruments and subsystems designed in this investigation including bespoke flow meters and a film extraction system. Most flow loop controls were automated using a MATLAB program. Reference measurement of the total water flow rate was made using a calibrated turbine flow meter and of the air flow rate using a calibrated rotameter. For the combined ultrasonic/conductance method investigated in this thesis, the velocity of the gas in the core was found using a novel Ultrasonic Flow Meter (USFM). The positioning and arrangement of the transducers have never been used previously. The flow velocity of the liquid film and the thickness of the film were measured using a novel Conductance Flow Meter (CFM). The CFM measured the liquid film thickness using novel wall conductance probes. By cross correlating the signals from a pair of such probes the film velocity was obtained. Good agreement of the experimental results obtained from the CFM and USFM with results published in the literature was found. Although not investigated experimentally in the work described in this thesis, annular flows encountered in the oil industry may contain a liquid phase comprising a mixture of oil and water. For such flows, the volume fractions of the oil and water can be measured using an automated bypass system developed during this project. The bypass system periodically extracts part of the liquid film, measures its density and then releases the sample back into the pipeline. The liquid phase volume fractions are determined from this density measurement which can be performed more than once per minute. An entrainment model was developed, which is required by the ultrasonic/conductance flow metering technique described in this thesis, in which the mass fraction of the liquid flowing as entrained droplets in the core can be determined from the liquid film thickness and velocity measurements. A mathematical model was also developed to describe the properties of the liquid film, such as liquid velocity profile within the film, and the model’s results were found to agree with the experimental results obtained during the project and also with previous work cited in the literature. The complexity of this latter model was reduced by making a number of simplifying assumptions, which are presented and discussed in the thesis, including the assumption that in annular flow there is a dynamic balance liquid entrainment and droplets being deposited back onto the film. The combination of the designed CFM and USFM with the bypass tube and the entrainment model offer the opportunity for a ‘wet gas’ flow meter to be developed to measure two and three phase annular flows at relatively low cost and with enhanced accuracy. Such a device would have the advantage that it would by substantially smaller than systems using separators and it could even be retrofitted onto off-shore platforms. The integration of the subsystems developed in this project into a single system capable of giving on-line measurements of annular flow would be a major benefit to the author’s sponsor, Petroleum Development of Oman.

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The aim of this Thesis is to obtain time-accurate solutions of the Navier-Stokes equations for laminar incompressible unsteady flows generated by oscillating boundaries in an annular region made from two concentric cylinders. For this, a time-dependent coordinate transformation is first used to obtain a fixed computational domain. The resulting governing equations in the fixed domain are discretized in real time based on a three-time-level implicit scheme. A pseudo-time integration with artificial compressibility is then used to reduce the resulting coupled discretized equations in delta form to set a decoupled scalar tridiagonal systems.
The method of solution has been applied to various 3-D unsteady flows in annular geometries, as well as to 2-D annular flows. The numerical results obtained are compared with those based on a mean position analysis, without transformation, for small-amplitude oscillation. This comparison shows that the time-dependent coordinate transformation is necessary to obtain accurate solutions for larger-amplitude oscillations.
The mean-position approach has also been applied to the analysis of axially variable annular configurations. The results obtained show more pressure recovery after a diffuser section with 6$ sp circ$ half-angle than in the case of 20$ sp circ$ half-angle.
A comprehensive experimental study was conducted to validate the theoretical results in the range of laminar flow. The results obtained were in good agreement with the numerical results, specially with those obtained by the time-dependent coordinate transformation. Experiments were also conducted for turbulent flow.
Based on the theoretical models developed, a computational method has been used to study fluid-structure interaction phenomena. It was applied to several cylindrical annular configurations in which one side of the annulus, the outer cylinder, is assumed to be flexibly supported, and thus to be susceptible to flow-induced instabilities. The structural and N-S equations were solved simultaneously by employing the numerical method developed for the unsteady flow and a fourth-order Runge-Kutta scheme for the structural motion. The numerical results thus obtained have predicted the stability of the structure for different annular geometries. The structure having a uniform annular geometry was shown to be more damped, while the annular geometry with a backward facing step is less damped. The study of the structure for a uniform annular geometry in the case of the rocking motion of the outer cylinder predicts an instability in the form of flutter of the outer cylinder.

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This thesis presents the results of the investigations in two areas, i.e. non-Newtonian annular flow and cuttings transport in drilling annuli at various angles. In the first part of the thesis, a review of the fundamentals and the previous studies on laminar concentric annular flow of non-Newtonian fluids is given at first. Then two parallel theoretical studies are performed, respectively, on: a. Laminar eccentric annular flow of power-law and Bingham plastic fluids. In this analysis, a new method is used which treats an eccentric annulus as infinite number of concentric annuli with variable outer radius. The analytical solutions of the shear stress, shear rate, velocity and the volumetric flowrate/pressure gradient are obtained over the entire eccentric annulus. This analysis is useful in design of any engineering operations related to eccentric annular flow such as oil drilling operations. b. Laminar helical flow of power-law fluids through concentric annuli. A group of dimensionless equations are derived in this analysis for the profiles of the apparent viscosity, angular and .axial velocities, and for the volumetric flowrate. These equations are essential when one needs to simulate the helical flow conditions in various engineering operations. In addition, another group of dimensionless equations are also derived for pressure gradient calculations which can be used directly by drilling engineers to predict the reduction of the annular friction pressure drop caused by drillpipe rotation during drilling operations. The second part of the thesis is dedicated to the investigations into the problems directly related to cuttings transport through drilling annuli at various angles. First, both theoretical and experimental studies on settling velocities of drilled cuttings in drilling fluids are conducted using new approaches to account for the non-Newtonian nature of drilling fluids and for the shape irregularity of drilled cuttings. Based on experimental results, a generalised model is developed for calculating settling velocities of variously shaped particles in power-law fluids. Then, the effects of various parameters on cuttings transport during drilling operations are analysed based on the previous and the present studies. After that, an extensive theoretical analysis for the previous studies on the minimum transport velocity (MTV) in solid-liquid mixture flow through pipelines, on initiation of sediment transport in open channels and on MTV for cuttings transport in deviated wells is presented. At last, theoretical studies on the minimum transport velocity for cuttings transport in drilling annuli at various angles are conducted and two parallel general correlations are developed. When these correlations are experimentally verified and numerically established in the future, they can be served as general criteria for evaluating and correlating the effects of various parameters on cuttings transport, and as a guideline for cuttings transport programme design during directional drilling.

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By introducing a quarterwave plate into a video polarimeter, we are able to extract all Stokes parameters of light scattered from any sample.2 After mapping out the degree of polarization of a linearly polarized light transmitted through a polycarbonate plate, we can observe the flow lines from the contour of its degree of polarization. In flows, the axisymmetrical particles tend to be oriented along the direction of flow, and are usually used as seeds for flow visualization. Since a PC-plate is constructed by long-chain polymers, the contour of its polarization properties can provide a visible flow with embedded seeds. Besides, the solid structure of the PC-plate is an ideal frozen flow for studying. A numerical simulated flow is used for comparison.

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In describing the laminar flow mirrors, a general comparison between laminar flow cooling and turbulent flow cooling shows that the two cooling techniques can achieve comparable mirror thermal performance. However, the cooling flow rates required for the laminar flow mirrors can be significantly reduced. The emphasis of reducing the hydraulic diameter as the primary scheme to increase the film transfer coefficient in the laminar flow cooling technique is significantly different from that employed in conventional turbulent cooling, which relies on high fluid velocity to achieve the same objective. The fabrication technology of such laminar flow mirrors is being developed.

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Abstract Hydrocarbon production is commonly associated as the dispersed flow of two and more immiscible phases starting from porous media to surface facilities. In the dispersed flow, one phase is usually dispersed into another dominating phase in terms of droplets. Accurate prediction of the droplet size distribution of a dispersed phase is critical in characterizing complex flow behavior in pipe flows. In the first part of this paper, we provide the analyses of open-source experimental data on the maximum droplet size in gas-liquid annular flow and evaluate the existing theoretical models and suggest an improvement based on the experimental data analyses to predict the maximum droplet size of the entrained liquid droplets in gas-liquid annular flow. In the second part of this paper, we cover the experimental results from the open-source literature data and in-house experimental data to give the general understanding on droplet formation concepts and evaluate the existing predictive models and present a new modeling approach to determine a maximum stable droplet size of the dispersed phase in the liquid-liquid dispersed flow under turbulent flow conditions.

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This report presents the methods, results, and applications of an updated flood-frequency study for the State of Illinois. This study, which uses data through September 2017, updates two previous studies that used data through 1999 and 2009, respectively. Flood-frequency estimates are used for a variety of land-use planning and infrastructure design purposes, including for the hydraulic design of bridges. The flood frequencies presented are the stream discharges (or quantiles) that are exceeded each year with a given probability, called the annual exceedance probability (AEP). Estimates are provided for eight AEPs: 0.5, 0.2, 0.1, 0.04, 0.02, 0.01, 0.005, and 0.002. The basic data used are the annual maximum discharges (peak flows) at streamgages in and near Illinois and the measurable physical properties (basin characteristics) of the basins upstream from those streamgages. The logarithms of the peak-flow records at qualifying streamgages were fit to the Pearson Type 3 distribution using federally recommended methods, providing one of the two primary products of the study, which is the set of peak-flow quantiles at the streamgages and their uncertainties. The other primary product is sets of equations, determined by least-squares regression, that relate the peak-flow quantiles and the basin characteristics. There is one set of equations for each of Illinois’ seven hydrologic regions, and, for each region, one equation for each AEP. These regional equations allow the estimation of peak-flow quantiles at ungaged locations throughout the state and their uncertainties. A set of illustrative example applications is provided, and tables of all results at all study streamgages and regions are provided in associated data releases. The study results are also being made available in a web application, StreamStats.

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This report contains data that demonstrates the scaling of flow regime, pressure drop, and holdup multiphase flow with pipe diameter. In addition, entrance length effects, the onset of liquid entrainment, and interfacial shear modeling at high gas density were studied for purposes of validating multiphase flow design methods. Stratified, slug and annual flow regimes were observed in a 112-foot long 3.5-inch diameter test section. Air, freon, and water were used to represent pipeline fluids.

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