1,721,009 research outputs found
CFD-DEM and machine learning for modelling of plugging in pipes with cohesive particles
No full textThis dataset contains model data for the CFD-DEM simulation of plugging in multiphase flows with cohesive particles. The main results available from the simulations are presented in the dataset together with the overall description of the model.
The second model is the random forest-based machine learning (ML) routine trained using experiments and CFD-DEM simulations. The source of the ML model is provided together with the training dataset.</p
Flow loop plugging experiments: experimental logs
No full textFlow loop sensor logs for plugging flow experiments which are described in the associated articles. The logs present experimental pressure, temperature, and mass flow rate measurements conducted at different places of the multiphase flow loop loaded with ice-in-decane slurry. The experiments were performed for various flow rates, particle concentrations, and medium temperatures
Numecial studies of agglomeration and deposition in a viscous flow
No full textConsulta en la Biblioteca ETSI Industriales (Riunet)[EN] As conventional reservoirs, known as “easy oil”, are exhausted, the deep water and sub-sea are being explored by the energy producers. Despite the difficulty accessibility of, the companies have to struggle with a high economic impact due to the hydrates formation and the subsequent plugging of the pipeline. Methods of knowing where and when it will take place are needed to prevent the formation and act effectively with the prevention methods available.
In the present paper the study of the dependence of the diameter of particles as a function of different parameters and time is presented. To do that, the surface energy and Young’s modulus will be varied in a simplified model that mimics a Couette system. Particle velocity and Reynolds number as a function of time and surface energy; fractal dimension of aggregates with time for different Young’s modulus and surface energy values; particle size as a function of Flow number are considered.
The deposition of cohesive particles from the turbulent flow in bend has been considered for different ben curvatures. The objective is to study the location of the depositions of hydrates in the connecting elements of pipes, in particular bends, which are used in the transport of oil and gas. It is intended to analyze when the deposition in the bend is bigger for different curvatures of it. We expect to get a result that enables us to relate the curvature of the connecting element with the formation of depositions and the subsequent agglomeration of hydrates. The purpose of this study is to obtain, in a visual way, the behavior of the solid particles present in the fluids and conveyed through the pipelines in order to conclude it there is a dependency between the curvatures the best configuration of the connecting elements more used in facilities of the bend. Is directly dependent on the curvature in these connecting? Can we get a curvature for which the deposition is minimal or non-existent? These questions are to be solved in this study.
It is expected that the results obtained will help to a better understanding on how some parameters affect to the hydrates formation.Lucas Pérez, M. (2014). Numecial studies of agglomeration and deposition in a viscous flow. https://riunet.upv.es/handle/10251/44096.Archivo delegad
Numerical studies of agglomeration and deposition in a viscous flow: mean size, structure of agglomerates and influence of flow configuration on deposition
No full textConsulta en la Biblioteca ETSI Industriales (Riunet)[EN] As conventional reservoirs, known as “easy oil”, are exhausted, the deep water and sub-sea are being explored by the energy producers. Despite the difficulty accessibility of, the companies have to struggle with a high economic impact due to the hydrates formation and the subsequent plugging of the pipeline. Methods of knowing where and when it will take place are needed to prevent the formation and act effectively with the prevention methods available.
In the present paper the study of the dependence of the diameter of particles as a function of different parameters and time is presented. To do that, the surface energy and Young’s modulus will be varied in a simplified model that mimics a Couette system. Particle velocity and Reynolds number as a function of time and surface energy; fractal dimension of aggregates with time for different Young’s modulus and surface energy values; particle size as a funtion of Flow number are considered.
The deposition of cohesive particles from the turbulent flow in bend has been considered for different ben curvatures. The objective is to study the location of the depositions of hydrates in the connecting elements of pipes, in particular bends, which are used in the transport of oil and gas. It is intended to analyze when the deposition in the bend is bigger for different curvatures of it. We expect to get a result that enables us to relate the curvature of the connecting element with the formation of depositions and the subsequent agglomeration of hydrates. The purpose of this study is to obtain, in a visual way, the behavior of the solid particles present in the fluids and conveyed through the pipelines in order to conclude it there is a dependency between the curvatures the best configuration of the connecting elements more used in facilities of the bend. Is directly dependent on the curvature in these connecting? Can we get a curvature for which the deposition is minimal or non-existent? These questions are to be solved in this study.
It is expected that the results obtained will help to a better understanding on how some parameters affect to the hydrates formation.Mateu Ros, P. (2015). Numerical studies of agglomeration and deposition in a viscous flow: mean size, structure of agglomerates and influence of flow configuration on deposition. https://riunet.upv.es/handle/10251/57758.Archivo delegad
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Conveccion natural en un colector solar parabolico con un nanofluido. Desarrollo de un ciclo.
No full text[ES] Este proyecto estudia el comportamiento de un circuito de flujo de vapor y sus propiedades.
El primer paso ha sido el desarrollo de un sistema adecuado en el que es posible
obtener medidas válidas. Despues se han comparado varios sistemas para encontrar el más eficiente. Dado que la producción de energía es una piedra angular de
la sociedad, es importante mejorarla tanto como sea posible. No solo por la relación costo-beneficio, si no también por su influencia en el medio ambiente
Finalmente, se han obtenido algunos resultados que muestran que el nano fluido es mucho mas eficiente que el agua, sin embargo, es solo un pequeño paso
en una escala mucho mayor de investigación que tiene que hacerse.[EN] This project studies the behaviour of a steam flow loop and its properties.
The first step has been the development of a suitable system in which it is possible to
obtain valid measurements. Then a comparison between several systems has been
made to find the most efficient one. Since the energy production is a cornerstone of
every society, it is important improve it as much as possible. Not only because of the
cost-benefit ratio, but also for the environment side.
Finally, some interesting results have been obtained, nevertheless, it is only a small step
in a much larger scale of research that has to be made.González Sanjuán, J. (2018). Natural Convection in a Parabolic Solar Collector with Nanofluid: Flow-Loop Development. Universitat Politècnica de València. https://riunet.upv.es/handle/10251/139194TFG
Computational Study of Hydraulic Accumulators
No full textThe scope of this project is to make a CFD model to be used for getting a better
understanding of accumulator discharge. To be able to establish the models credibility is
there a need for validation of the models developed. First a model of one accumulator is
to be validated by use of an experimental project as well as an analytical approach. This
model is then to be adapted to a system of two accumulators in series to be studied and
validated by a theoretical equation developed.
The literature review reveal that the study of accumulator discharge for applications
for the oil industry is not a area were many articles is presented, which makes the scope of
this thesis more interesting.
The first case studied is a single bladder-type accumulator, which is discharged through
three different outlet areas and has an internal volume of 4 l, with a pre-charge pressure of
2 bar. The physical model developed is validated by experimental data, and a theoretical
approach to establish the models credibility. The average discrepancies obtained from
the results was below 12.56% for all cases modeled. These results shows a high level
of agreement to the various validation points, which leads to significant credibility of the
physical model developed. This model is then to be adapted to the following cases in this
study.
The second case studies discharge of a set of two 40 l accumulators placed in series
with different pre-charge pressures, but equal charge pressure. The case studies the effect
of changing the ambient temperature, outlet area of the discharge nozzle, and different outlet
pressures (backpressure). The obtained results shows that the effect of various ambient
temperature will not have a significant impact on the discharge pattern, but by changing the
restrictions in the outlet nozzle the profiles obtained showed great deviation from the base
case computation. Where the variation of outlet area of the nozzle had a bigger impact
on the discharge than by changing the backpressure in the system. An observation from
this case shows that the pressure drop in the accumulator with the lowest pre-charge had a
rapid pressure drop in the first part of the discharge cycle. This pressure drop is caused by
the flow pattern out of the given accumulator.
The last case studied is a similar case as the one above, but with accumulator volumes
of 10 l each. In this case the effect of changing the pre-charge order, as well as
the backpressure was studied. The results obtained from this study shows that changing
the pre-charge order will provide a more constant pressure delivery without a rapid pressure
drop in the system. This will result in a more stable and predictable flow out of the
hydraulic system studied. Even when changing the restrictions in the outlet nozzle, the
results shows a more stable flow out of the system, with similar pressure profiles
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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