Interpretation Challenges and Solutions for Real-Time Asphaltene Paramagnetic Sensing at the Wellhead

Asphaltene deposition presents a significant flow assurance to oil production in many parts of the Middle East and beyond. Until recently, there had been no intervention-free approach to monitor deposition in the asphaltene affected wells. This prompted ADNOC to sponsor MicroSilicon to develop of an intervention less real-time sensor device to monitor asphaltene deposition. This new state-of-the-art device is currently installed and automatically collecting data at the wellhead and nearby facilities of an ADNOC operated field. Historic ways of measuring asphaltene in oil relied upon laboratory processes that extracted the asphaltene using a combination of solvents and gravimetric techniques. Paramagnetic techniques offer a potentially simpler alternative because it is known that the spins per gram of an oil is a constant property of that oil, at least when the oil is at constant temperature and pressure. Taking the device to the field means that any interpretation needs to be made independent of these properties. Additionally, the fluid entering the sensor is multiphase and subject to varying temperature and pressure which raises challenges for the conversion of raw spectroscopic data into asphaltene quantity and particle size. These challenges were addressed with a combination of hardware, software and cloud-based machine learning technologies. Oil from over two dozen wells has been sampled in real-time and confirmed that the asphaltene percentage does not just vary from well to well but is also a dynamic aspect of production, with some wells having relatively constant levels and others showing consistent variation. One other well was placed on continuous observation and showed a decrease in asphaltene level following a choke change at the surface. Diagnostic data enhanced by machine learning complements the asphaltene measurement and provides a much more complete picture of the flow assurance challenge than had been previously been available.

CFD study of Convective Heat Transfer of Water Flow Through Micro-Pipe with Mixed Constant Wall Temperature and Heat Flux Wall Boundary Conditions

The dissipation of heat in tiny engineering systems can be achieved with fluid flow through micro pipes. They have the advantage of less volume to large surface ratio convective heat transfer. There are deep-rooted analytical relations for convective heat transfer available for fluid flow through macro size pipes. But differences exist between the convective heat transfer for fluid flow through macro and micro pipes. Therefore, there is a good scope of work in micro convection heat transfer to study the mechanism of fundamental flow physics. There have been studies with either constant heat flux wall boundary conditions or constant wall temperature boundary conditions with constant and variable property flows. In this article, first, the numerical simulations are validated with the experimental data for 2D axisymmetric conventional pipe with pipe diameter of 8 mm is taken with laminar, steady, and single-phase water flows with constant wall heat flux boundary condition of 1 W/cm2. The computed Nusselt number is compared to the experimental results at different Reynolds numbers of 1350, 1600 and 1700. In the next study, three-dimensional micropipe laminar flow is studied numerically using water with an inlet velocity of 3 m/s and pipe diameter of 100 µm. The mixed wall boundary conditions with upper half pipe surface subjecting to constant wall temperature of 313 K and lower half surface subjecting to 100 W/cm2 are used in the simulations. The focus of research would be to consider the effect of temperature-dependent properties like thermal conductivity, viscosity, specific heat, and density (a combined effect we call it as variable properties) on micro-pipe flow characteristics like Nusselt number at mixed wall boundary conditions and compare it with the constant property flows. The conventional pipe showed no significant difference with variable and constant property flows with different Reynolds numbers. On contrary the flow through 3D micropipe shows that the Nusselt number with variable property flows is less as compared to the constant property flows.

Семантика абсолютивной конструкции В русском языке и антипассив

Данная работа рассматривает абсолютивную конструкцию переходных глаголов в русском языке в соотношении с антипассивом. Переходные глаголы определяются как глаголы, имеющие возмож-ность сочетаться с прямым объектом, т. е. обладают пациентной валентностью. Однако по разным причинам они могут не реализовывать пациентную валентность.Поскольку безобъектное употребление глагола – это результат синтаксической невыразимости пациентного аргумента, логично подходить к нему как к результату сокращения валентностных потенций. С этой точки зрения можно предположить, что безобъектная конструкция переходных глаголов имеет определенные диатетические характеристики. Мы постулируем, что невербализа-ция пациентной валентности сигнализирует о переносе пациентного аргумента на семантическую, коммуникативную периферию, и, следовательно, о его синтаксическом понижении.Выделяются три типа невербализации пациентного аргумента: контекстный эллипсис, семанти-ческая инкорпорация объекта в значение глагола и генерализованная презентация ситуации. Нас интересует прежде всего третий тип, и именно относительно этого типа традиционно применяется термин «абсолютивная конструкция». В отличие от первого и второго типов, в которых невыражен-ный объект восстанавливается через контекст или семантику глагола, в абсолютивной конструкции объект действия не может быть специфицирован, или это делается с трудом. Поэтому абсолютивная конструкция не является неполной конструкцией.Aбсолютивное употребление переходных глаголов – это результат сокращения валентности ком-муникативно нерелевантного объекта, что порождает определенные семантические сдвиги; глагол обозначает не акциональное действие, направленное на какой-то объект, а нечто более стативное, постоянное свойство субъекта, что переносит глагол в иные семантические классы и обусловливает его употребление в определенных контекстах.Абсолютивная конструкция и антипассив имеют общее функциональное сходство, а именно низ-кую дискурсивную выделенность объекта действия и генерализованную репрезентацию ситуации как постоянного свойства субъекта. В русском языке типичным показателем антипассива являет-ся возвратная частица -ся. Поэтому в случаях несущественности, очевидности, неопределенности объекта действия абсолютивная конструкция и антипассивный возвратный глагол могут функцио-нировать синонимично. Ср.: Горчичник сильно жжет Ø / сильно жжется. Следовательно, в данной статье абсолютивная конструкция сравнивается с антипассивными рефлексивными глаголами типа Собака кусается. В русском языке семантический круг антипассивных рефлексивных глаголов от-носительно узок, и это объясняется тем, что их функцию вполне могут заменить невозвратные гла-голы в абсолютивном употреблении.Кроме того, остальные типы опущения пациентной валентности также имеют соотношение с возвратными глаголами других разрядов, но детальное обсуждение этого вопроса станет темой наших дальнейших исследований.This work examines the absolute construction of transitive verbs in Russian in relation to the antipassive. Transitive verbs are defined as verbs that can be combined with a direct object, i.e. they exhibit patient valency. However, for various reasons, this patient valency is not always realized.Since the objectless use of the verb is the result of the syntactic inexpressibility of the patient argument, it is logical to approach it as the result of valency-reducing derivation. From this point of view, it can be assumed that the objectless transitive construction has certain diathetic properties. We postulate that the non-verbalization of patient valency signals the transfer of the patient argument to the semantic, communicative periphery and, consequently, to its syntactic demotion.Three types of non-verbalization of the patient argument are distinguished: context ellipsis, semantic incorporation of an object into the meaning of a verb, and generalized presentation of the situation. We are primarily interested in the third type, for which the term absolute construction is traditionally used. Unlike the first and second types, in which the unexpressed object is reconstructed through the context or semantics of the verb, in the absolute construction, the object of action cannot be specified, or it is diffi cult to do so. Therefore, an absolute construction is not an incomplete construction.The absolute use of transitive verbs is the result of reducing the valency of a communicatively irrelevant object, which generates certain semantic shift s; a verb does not denote an action directed at a concrete object but instead denotes something more stative, a constant property of the subject, which transfers the verb to other semantic classes and determines its use in certain contexts.The absolute construction and the antipassive function similarly in that both rely on the low discursive saliency of the object of action and the generalized representation of the situation as a constant property of the subject. In Russian, a typical indicator of an antipassive is the reflexive -ся. Therefore, when the object of action is insignificant, obvious or ambiguous, the absolute construction and the antipassive reflexive verb can function synonymously (e.g. Горчичник сильно жжет Ø / сильно жжется). Therefore, in this paper, the absolute construction is compared with antipassive reflexive verbs such as Собака кусается. In Russian, the semantic circle of antipassive reflexive verbs is relatively narrow, and this is due to the fact that their function may be replaced by irreflexive verbs in absolute use.In addition, the remaining types of omission of patient valency also have a correlation with reflexive verbs of other categories but a detailed discussion of this issue will be reserved for future research.

Estimating the forcing function in a mechanical system by an inverse calibration method

This article proposes and demonstrates a calibration-based integral formulation for resolving the forcing function in a mass–spring–damper system, given either displacement or acceleration data. The proposed method is novel in the context of vibrations, being thoroughly studied in the field of heat transfer. The approach can be expanded and generalized further to multi-variable systems associated with machine parts, vehicle suspensions, translational and rotational systems, gear systems, etc. when mathematically described by a system of constant property, linear, time-invariant ordinary differential equations. The analytic approach and subsequent numerical reconstruction of the forcing function is based on resolving a parameter-free inverse formulation for the equation(s) of motion. The calibration approach is formulated in the frequency domain and takes advantage of several observations produced by the dimensionality reduction leading to an algebratized system involving an input–output relationship and a transfer function possessing all the system parameters. The transfer function is eliminated in lieu of experimental data, from a calibration effort, thus leading to a reduction of systematic errors. These parameter-free, reduced systematic error aspects are the distinct and novel advantages of the proposed method. A first-kind Volterra integral equation is formed containing only the unknown forcing function and experimental data. As with all ill-posed problems, regularization must be introduced for system stabilization. A future-time technique is instituted for forming a family of predictions based on the chosen regularization parameter. The optimal regularization parameter is estimated using a combination of phase–plane analysis and cross-correlation principles. Finally, a numerical simulation is performed verifying the proposed approach.

Numerical Modelling and Experimental Validation of a Supercritical Co2-lubricated Hydrodynamic Journal Bearing

This paper describes the development of a simple numerical model of a hydrodynamic journal bearing operating under laminar conditions. The model incorporates the real gas properties of sCO2 and therefore can be used to qualitatively investigate the impact of operation near the critical point. The model predictions are compared to a model assuming constant fluid properties in order to assess the effects of the large gradients in properties that occur near the critical point. The modeling results show that bearing drag should not rise significantly throughout the subcritical regime, but rises by approximately 50% at the critical pressure. Similarly, bearing stiffness increases by about 50% at the critical pressure. However, the behavior predicted by the real gas model closely matches those obtained from the constant-property model for all conditions that are more than 3 kPa away from the critical pressure. To demonstrate operation near the critical pressure, a test assembly consisting of a turbomachine driven by a motor and supported on tilt-pad hydrodynamic gas journal bearing was operated in a high-pressure CO2 environment at 35°C with pressures up to 1050 psig. The bearing operated smoothly and did not exhibit signs of instability such as whirl. Coast down measurements were conducted to estimate the bearing drag at various pressures up to 800 psig. These results indicate that hydrodynamic bearing operation using sCO2 is possible without significant reduction in bearing performance; however, further testing should be carried out in order to validate the model results concerning bearing stiffness.

Computational fluid dynamic simulations and heat transfer characteristic comparisons of various arc-baffled channels

In this analysis, the baffling method is used to increase the efficiency of channel heat exchangers (CHEs). The present CFD (computational fluid dynamics)-based work aims to analyze the constant property, steady, turbulent, Newtonian, and incompressible fluid flow (air), in the presence of transverse-section, arc-shaped vortex generators (VGs) with two various geometrical models, i.e., arc towards the inlet section (called arc-upstream) and arc towards the outlet section (called arc-downstream), attached to the hot lower wall, in an in-line situation, through a horizontal duct. For the investigated range of Reynolds number (from 12,000 to 32,000), the order of the thermal exchange and pressure loss went from 1.599–3.309 to 3.667–21.103 times, respectively, over the values obtained with the unbaffled exchanger. The arc-downstream configuration proved its superiority in terms of thermal exchange rate by about 14% than the other shape of baffle. Due to ability to produce strong flows, the arc-downstream baffle has given the highest outlet bulk temperature.

On Polyekthetic Processes

This Preprint introduces polyekthetic processes, a generalization of polytropic processes. The etymology of the new term is given, and the concept is explained theoretically. A useful associated definition for constant-property processes, for arbitrary properties and expressions thereof, is given, and associated polyekthetic exponents k_ijℓ are defined and a general solution is obtained. Examples on van-der-Waals, general, and ideal gas substances are provided with discussions.

Effect of Thermophysical Property Variation on Entropy Generation towards Micro-Scale

In this work, the effect of temperature-dependent thermal conductivity (k(T)) and viscosity (\mu (T)) variation on entropy generation in circular channels with an approach from macro- to micro-scale is numerically investigated. Thermally as well as hydrodynamically fully developed flow of water through the fixed length channels with constant total heat flow rate and total mass flow rate is considered. The effects of k(T) variation and \mu (T) variation on entropy generation are analyzed individually as well as collectively. It is observed that in the case of Constant Property Solutions (CPS) {S_{\mathit{gen},\mathit{tot}}} is maximum at the macro-level; however, in the case of combined k(T) and \mu (T) variations it is maximum at the micro-level. The Bejan number (\mathit{Be}) and irreversibility distribution ratio (φ) are also calculated for asserting the dominance of frictional irreversibility and conduction heat transfer irreversibility. Additionally, the optimum diameter ({D^{\ast }}) corresponding to the optimum number of channels is calculated at minimum total entropy generation. It is observed that {D^{\ast }} is minimum for k(T) variation followed by CPS, \mu (T) variation, and combined k(T) and \mu (T) variations.

Speech Recognition by Dynamic Time Warping Assisted SVM Classifier

Speech recognition using sustenance vector machine assisted by Dynamic time warping (DTW) method is proposed. The input training datas are collected from 40 speakers for five unique words. Every one of the information was gathered in a profoundly acoustic and commotion confirmation condition. Mel recurrence cepstrum coefficients (MFCC's) are represented as constant property of the signal. First and second derivatives of MFCC are used for dynamic properties. Subsequent to deciding element vectors, an adjusted DTW technique is proposed for highlight coordinating. Support Vector Machine (SVM) as well as Radial basis function (RBF) are used to categorize. The model is tried for multiple speakers and a good detection rate is obtained.

Effect of wall-mounted V-baffle position in a turbulent flow through a channel

Purpose The purpose of this paper is to carry out a numerical study on the dynamic and thermal behavior of a fluid with a constant property and flowing turbulently through a two-dimensional horizontal rectangular channel. The upper surface was put in a constant temperature condition, while the lower one was thermally insulated. Two transverse, solid-type obstacles, having different shapes, i.e. flat rectangular and V-shaped, were inserted into the channel and fixed to the top and bottom walls of the channel, in a periodically staggered manner to force vortices to improve the mixing, and consequently the heat transfer. The flat rectangular obstacle was put in the first position and was placed on the hot top wall of the channel. However, the second V-shaped obstacle was placed on the insulated bottom wall, at an attack angle of 45°; its position was varied to find the optimum configuration for optimal heat transfer. Design/methodology/approach The fluid is considered Newtonian, incompressible with constant properties. The Reynolds averaged Navier–Stokes equations, along with the standard k-epsilon turbulence model and the energy equation, are used to control the channel flow model. The finite volume method is used to integrate all the equations in two-dimensions; the commercial CFD software FLUENT along with the SIMPLE-algorithm is used for pressure-velocity coupling. Various values of the Reynolds number and obstacle spacing were selected to perform the numerical runs, using air as the working medium. Findings The channel containing the flat fin and the 45° V-shaped baffle with a large Reynolds number gave higher heat transfer and friction loss than the one with a smaller Reynolds number. Also, short separation distances between obstacles provided higher values of the ratios Nu/Nu0 and f/f0 and a larger thermal enhancement factor (TEF) than do larger distances. Originality/value This is an original work, as it uses a novel method for the improvement of heat transfer in completely new flow geometry.