Добірка наукової літератури з теми "Avoiding cones conditions"

The advanced technique of shock-kinematic analysis of the bit roller cone interaction with rock in the process of oil and gas wells drilling is proposed. Preliminary investigations of the interaction of the roller cone bits with rock were based on assumptions far from reality: the concept of the instantaneous axis of rotation of the roller cone constant contact with rock, the absence of slipping, as well as the tooth reforming and sinking into rock. The principle of the roller cones action is the gradual destruction of the surface of the bottomhole due to the cutting-crushing chipping of rock with a bit tooth.The axial roller cone is considered, and the original method of planes projection is used to determine the regulation of tooth motion, taking into account: bit roller cones slipping along the surface of the bottomhole; phases of roller cone tooth sinking into rock; real change in the distance of the axis of rotation of the roller cone to the surface of the bottomhole due to tooth penetration into the rock; the substantiation of the conditions for avoiding the roller cone tooth entering to the previously obtained hole in the process of bottomhole crushing. Besides the moment of the drill string inertia, the moments of roller cones inertia are additionally taken into account under the condition of the oblique impact of the tooth on the rock.The technique allows to calculate the volume of the disintegrated rock on the bottomhole, both taking into account and without taking into account rock chipping and tooth forming. The obtained dependencies allow us to select transmitted ratios from the drill string to the crowns of the roller cones under the condition of avoiding the roller cone tooth to the previously obtained hole during rock destruction on the bottomhole. It allows increasing the efficiency of drilling by roller cones.

The lane change of vehicles for avoiding hitting a sudden obstacle represents a significant and unique problem for traffic accident experts. Most mathematic models for determining the lane change distance are based on theoretical research studies and a lot of simplifications and approximations. In order to analyse the influence of different drivers and vehicles on a manoeuvre, an experimental research study of lane change was carried out at the test track which enables repeatability in the same conditions. The drivers were instructed to drive through the test track at a maximum speed without displacing the traffic cones. Based on the statistical analyses of the successful lane change manoeuvres an empirical model for the calculation of lane change distance for obstacle avoidance was formed. This model can be applied in the procedure of traffic accident reconstructions as well as within the development of the concept of modern intelligent vehicles.

Zero-dimensional/one-dimensional computational fluid dynamics codes are used to simulate the performance of complete internal combustion engines. In such codes, the operation of a turbocharger compressor is usually addressed employing its performance map. However, simulation of engine transients may drive the compressor to work at operating conditions outside the region provided by the manufacturer map. Therefore, a method is required to extrapolate the performance map to extended off-design conditions. This work examines several extrapolating methods at the different off-design regions, namely, low-pressure ratio zone, low-speed zone and high-speed zone. The accuracy of the methods is assessed with the aid of compressor extreme off-design measurements. In this way, the best method is selected for each region and the manufacturer map is used in design conditions, resulting in a zonal extrapolating approach aiming to preserve accuracy. The transitions between extrapolated zones are corrected, avoiding discontinuities and instabilities.

Both efficiency and cavitation performance of the hydrofoil are the key technologies to design the tidal current turbine. In this paper, the hydrofoil efficiency and lift coefficient were improved based on particle swarm optimization method and XFoil codes. The cavitation performance of the optimized hydrofoil was also discussed by the computational fluid dynamic. Numerical results show the efficiency of the optimized hydrofoil was improved 11% ranging from the attack angle of 0-7? compared to the original NACA63-818 hydrofoil. The minimum pressure on leading edge of the optimized hydrofoil dropped above 15% at the high attack angle conditions of 10?, 15?, and 20?, respectively, which is benefit for the hydrofoil to avoiding the cavitation.

Architectural heritage masonry buildings located in seismic areas are highly prone to suffer damage under seismic loading, due to their structural features. In this study, the Salares medieval tower, which is placed in the province of Malaga (Spain) - a zone with high seismic hazard in the Iberian Peninsula- is adopted as a case study. This is a precious heritage building which exhibits severe damages, such as depth cracks and inclination. Owing to those reasons detailed seismic and dynamic analyses are crucial for its preservation. The present work is arranged in three sections that deal with seismic hazard analysis, selection of real acceleration time-histories representative of the site, and dynamic response by means of numerical models. In order to obtain the design earthquake at the specific location, different parameters were analyzed, namely the region seismic activity, the geotechnical and geological conditions at the site and the acceptable risk level. Hazard analysis was performed following deterministic and probabilistic methods. As far as the seismic input is concerned, real accelerogram representative of the 1884 Andalusia earthquake were selected. It was a destructive earthquake that caused catastrophic damages near the analyzed structure. The accelerograms thus obtained were used as input for subsequent non-linear dynamic analyses on three-dimensional finite element models. Different cracking capable constitutive models were considered in order to predict local and global collapse mechanisms. Moreover, the suitability of each model was discussed when crushing, high plastic deformation or response under cyclic loading are concerned. The aforementioned studies yield significant results in order to perform a comprehensive safety assessment under ground motion effects. Thus, regarding the seismic input, the obtained accelerogram provides a relevant application aimed at revising the maximum acceleration and the response spectra of the Codes, as seismic code recommendations are limited in those issues. Furthermore, the dynamic structural response via numerical approach, allows determining damage propagation and collapse probability as a main step to select appropriate repair measures. The followed method could be used to assess and improve the structural strength of similar architectural heritage buildings located in active seismic areas.

Character recognizers have generally focused on printed text on paper with an emphasis on generality rather than speed. This makes the proposed algorithms not applicable in the context of the very high-speed industrial validation of expiration codes printed on the metal surface of a can. The extreme demands of speed and the adverse effects of lighting and movement, among other things, make it necessary to develop an original and specific strategy. The strategy presented in this paper first selects which of the segmented shapes of a printed can are the best candidates for comparison with expected characters. This is followed by a technique based on the comparison of templates (templates matching), which we call “morphologies”, and are represented as bitmaps to take advantage of the hardware capabilities of general-purpose processors. The use of templates has the advantage of avoiding the construction of a feature vector. In an acquisition test in a real industrial plant, we have been able to successfully treat 438 cans in 44 s, with only one validation error in one character, achieving a compromise between speed and quality that is sufficient for industrial validation in the conditions cited.

INTRODUCTION: Oral conditions such as dental caries, periodontal diseases, tooth loss and trauma affect millions of people globally. These conditions can be prevented when detected early, thereby avoiding adverse outcomes. The prevalence of oral conditions has been reported in most provinces. However, there is a paucity of data in KwaZulu-Natal. AIM AND OBJECTIVE: This study aimed to determine the prevalence of oral conditions at public health facilities in two health districts in KwaZulu-Natal, South Africa. MATERIALS AND METHODS: A cross-sectional analytical study design was used to determine the nature of oral conditions treated in dental facilities in the eThekwini and uMgungundlovu districts, in KwaZulu-Natal. The study was conducted over a 5-month period (November 2018 - April 2019). After clinicians examined the patients they entered the data in the patients clinical records and selected information (routine medical history questions as well as 16 possible diagnosis codes) were entered into a data extraction template. The data were analyzed using statistical software SPSS. RESULTS: Dental caries was the most prevalent oral condition at 66.4% followed by periodontal disease at 11.7%, trauma at 7.3% and lastly tooth loss at 5.9% CONCLUSION: These findings contribute to knowledge on the prevalence of these oral conditions found in the province.

This thesis contains the work done by Paolo Gidoni during the doctorate programme in Matematical Analysis at SISSA, under the supervision of A. Fonda and A. DeSimone. The thesis is composed of two parts: "Avoiding cones conditions and higher dimensional twist" and "Directional friction in bio-inspired locomotion".

The trauma experienced by queer children and adolescents resulting from the societal stigmatizing of their sexuality may produce the post-traumatic conditions of avoidance, numbing, and dissociation. These conditions in turn may enable rich forms of musical expressiveness. The music of the pop duo, Pet Shop Boys, sometimes comes close to bringing a post-traumatic numbness into music itself. It is as though, in their case, the magic of dissociated musical expression has failed to offer its lifeline to the traumatized subject. This may sound like an artistic failure. But it can also be heard as a demystification, a refusal of the socially accepted queer expressiveness that succeeds only by avoiding the material that most needs expression.

Economy and mankind are inextricably interlinked. Just as the economy or the production of material wealth is unimaginable without a man, so human existence and development are impossible without the wealth created in the economy. Shortly, both the goal and the means of achieving and realization of the economy are still the human resources. People have long ago noticed that it was the economy that created livelihoods, and the delays in their production led to the catastrophic events such as hunger, poverty, civil wars, social upheavals, revolutions, moral degeneration, and more. Therefore, the special interest of people in understanding the regulatory framework of the functioning of the economy has existed and exists in all historical epochs [A. Sisvadze. Economic theory. Part One. 2006y. p. 22]. The system of economic disciplines studies economy or economic activities of a society. All of them are based on science, which is currently called economic theory in the post-socialist space (the science of economics, the principles of economics or modern economics), and in most countries of the world - predominantly in the Greek-Latin manner - economics. The title of the present book is also Modern Economics. Economics (economic theory) is the science that studies the efficient use of limited resources to produce and distribute goods and services in order to satisfy as much as possible the unlimited needs and demands of the society. More simply, economics is the science of choice and how society manages its limited resources. Moreover, it should be emphasized that economics (economic theory) studies only the distribution, exchange and consumption of the economic wealth (food, beverages, clothing, housing, machine tools, computers, services, etc.), the production of which is possible and limited. And the wealth that exists indefinitely: no economic relations are formed in the production and distribution of solar energy, air, and the like. This current book is the second complete updated edition of the challenges of the modern global economy in the context of the coronary crisis, taking into account some of the priority directions of the country's development. Its purpose is to help students and interested readers gain a thorough knowledge of economics and show them how this knowledge can be applied pragmatically (professionally) in professional activities or in everyday life. To achieve this goal, this textbook, which consists of two parts and tests, discusses in simple and clear language issues such as: the essence of economics as a science, reasons for origin, purpose, tasks, usefulness and functions; Basic principles, problems and peculiarities of economics in different economic systems; Needs and demand, the essence of economic resources, types and limitations; Interaction, mobility, interchangeability and efficient use of economic resources. The essence and types of wealth; The essence, types and models of the economic system; The interaction of households and firms in the market of resources and products; Market mechanism and its elements - demand, supply and price; Demand and supply elasticity; Production costs and the ways to reduce them; Forms of the market - perfect and incomplete competition markets and their peculiarities; Markets for Production Factors and factor incomes; The essence of macroeconomics, causes and importance of origin; The essence and calculation of key macroeconomic indicators (gross national product, gross domestic product, net national product, national income, etc.); Macroeconomic stability and instability, unemployment, inflation and anti-inflationary policies; State regulation of the economy and economic policy; Monetary and fiscal policy; Income and standard of living; Economic Growth; The Corona Pandemic as a Defect and Effect of Globalization; National Economic Problems and New Opportunities for Development in the conditions of the Coronary Crisis; The Socio-economic problems of moral obsolescence in digital technologies; Education and creativity are the main solution way to overcome the economic crisis caused by the coronavirus; Positive and negative effects of tourism in Georgia; Formation of the middle class as a contributing factor to the development of tourism in Georgia; Corporate culture in Georgian travel companies, etc. The axiomatic truth is that economics is the union of people in constant interaction. Given that the behavior of the economy reflects the behavior of the people who make up the economy, after clarifying the essence of the economy, we move on to the analysis of the four principles of individual decision-making. Furtermore, the book describes how people make independent decisions. The key to making an individual decision is that people have to choose from alternative options, that the value of any action is measured by the value of what must be given or what must be given up to get something, that the rational, smart people make decisions based on the comparison of the marginal costs and marginal returns (benefits), and that people behave accordingly to stimuli. Afterwards, the need for human interaction is then analyzed and substantiated. If a person is isolated, he will have to take care of his own food, clothes, shoes, his own house and so on. In the case of such a closed economy and universalization of labor, firstly, its productivity will be low and, secondly, it will be able to consume only what it produces. It is clear that human productivity will be higher and more profitable as a result of labor specialization and the opportunity to trade with others. Indeed, trade allows each person to specialize, to engage in the activities that are most successful, be it agriculture, sewing or construction, and to buy more diverse goods and services from others at a relatively lower price. The key to such human interactions is that trade is mutually beneficial; That markets are usually the good means of coordination between people and that the government can improve the results of market functioning if the market reveals weakness or the results of market functioning are not fair. Moroever, it also shows how the economy works as a whole. In particular, it is argued that productivity is a key determinant of living standards, that an increase in the money supply is a major source of inflation, and that one of the main impediments to avoiding inflation is the existence of an alternative between inflation and unemployment in the short term, that the inflation decrease causes the temporary decline in unemployement and vice versa. The Understanding creatively of all above mentioned issues, we think, will help the reader to develop market economy-appropriate thinking and rational economic-commercial-financial behaviors, to be more competitive in the domestic and international labor markets, and thus to ensure both their own prosperity and the functioning of the country's economy. How he/she copes with the tasks, it is up to the individual reader to decide. At the same time, we will receive all the smart useful advices with a sense of gratitude and will take it into account in the further work. We also would like to thank the editor and reviewers of the books. Finally, there are many things changing, so it is very important to realize that the XXI century has come: 1. The century of the new economy; 2. Age of Knowledge; 3. Age of Information and economic activities are changing in term of innovations. 1. Why is the 21st century the century of the new economy? Because for this period the economic resources, especially non-productive, non-recoverable ones (oil, natural gas, coal, etc.) are becoming increasingly limited. According to the World Energy Council, there are currently 43 years of gas and oil reserves left in the world (see “New Commersant 2007 # 2, p. 16). Under such conditions, sustainable growth of real gross domestic product (GDP) and maximum satisfaction of uncertain needs should be achieved not through the use of more land, labor and capital (extensification), but through more efficient use of available resources (intensification) or innovative economy. And economics, as it was said, is the science of finding the ways about the more effective usage of the limited resources. At the same time, with the sustainable growth and development of the economy, the present needs must be met in a way that does not deprive future generations of the opportunity to meet their needs; 2. Why is the 21st century the age of knowledge? Because in a modern economy, it is not land (natural resources), labor and capital that is crucial, but knowledge. Modern production, its factors and products are not time-consuming and capital-intensive, but science-intensive, knowledge-intensive. The good example of this is a Japanese enterprise (firm) where the production process is going on but people are almost invisible, also, the result of such production (Japanese product) is a miniature or a sample of how to get the maximum result at the lowest cost; 3. Why is the 21st century the age of information? Because the efficient functioning of the modern economy, the effective organization of the material and personal factors of production largely depend on the right governance decision. The right governance decision requires prompt and accurate information. Gone are the days when the main means of transport was a sailing ship, the main form of data processing was pencil and paper, and the main means of transmitting information was sending letters through a postman on horseback. By the modern transport infrastructure (highways, railways, ships, regular domestic and international flights, oil and gas pipelines, etc.), the movement of goods, services and labor resoucres has been significantly accelerated, while through the modern means of communication (mobile phone, internet, other) the information is spreading rapidly globally, which seems to have "shrunk" the world and made it a single large country. The Authors of the book: Ushangi Samadashvili, Doctor of Economic Sciences, Associate Professor of Ivane Javakhishvili Tbilisi State University - Introduction, Chapters - 1, 2, 3, 4, 5, 6, 9, 10, 11,12, 15,16, 17.1,18 , Tests, Revaz Shengelia, Doctor of Economics, Professor of Georgian Technical University, Chapters_7, 8, 13. 14, 17.2, 17.4; Zhuzhuna Tsiklauri - Doctor of Economics, Professor of Georgian Technical University - Chapters 13.6, 13.7,17.2, 17.3, 18. We also thank the editor and reviewers of the book.

Implementation of finite element method (FEM) needs special cares, particularly for essential boundary conditions that have an important effect on symmetry and number of unknowns in the linear systems. Moreover, avoiding numerical integration and using (off-line) calculated element integrals decrease the computational cost significantly. In this chapter we briefly present theoretical topics of FEM. Instead we focus on what is important (and how) to carefully implement FEM for equations that can be the core of a numerical simulator for a diffusion–advection-reaction problem. We consider general 2D and 3D domains, high contrast and heterogeneous diffusion coefficients and generalize the method to nonlinear parabolic equations. Although we use Matlab codes to simplify the explanation of the proposed method, we have implemented it in C++ to reveal the efficiency and examples are presented to admit it.

The term biometrics was defined to suggest any measurable biological and biomedical metrics that can be used to identify and confirm the uniqueness of individuals. In this chapter, we would like to introduce an emerging area of biometrics, MedMetrics, that combines patient and drug information managed in coded passports to keep medical information accessible, safe and fraud-resistance. Medmetics includes medical and biological biometrics of patients based on their electronic health records, International Classification of Disease codes, Anatomical Therapeutic Chemical codes, Defined Daily Doses, time-series test results, and personalizsed biological data. By combining the blockchain technology, Medimetrics enables sensitive data sharing in between different clinical settings, allowing monitoring patients’ health and care, as well as avoiding identification-related medical mistakes or frauds. MedMetrics Blockchain Passport can be used to identify patients and confirm their previous health conditions without the right of modifying or removing previous records. Medmetrics can revolutionary change the user demographic, shift safety restrictions, define new user applications, and encourage ethical AI regulations in medical science and health care. This chapter will discuss these directions and provide insights into the next generation of biometrics in medical science and health care.

Abstract The use of tracers as a diagnostic tool, represent a valid method, widely applied during waterflooding operations in the oil and gas industry, to gather information on the reservoir salient features. The main purpose of this work is the investigation of novel molecules, potentially applicable as inter-well tracers, with peculiar properties compared to standard products, such as the presence of fluorescence units which allows a more efficient detection. Moreover, the combined presence of chemical units sensitive to oil or other features of the formation, could allow the estimation of hydrocarbon content and porous media structure. The different tracer molecules under testing have been evaluated through a series of coreflooding tests on core plugs saturated with brine and at residual oil saturation, resembling reservoir conditions. The detection of the chemical species was performed by use of fluorescence spectroscopy directly on the fluids flushed out of the core, avoiding any complex handling of the solution. The method is potentially applicable to on-line detection directly on site. Different low molecular weight polymeric products with fluorescent properties were prepared for testing with the aim to evaluate their performance compared to standard tracers. In a preliminary screening procedure, the possible adsorption of the molecules on rock powder surface was evaluated. Only molecules showing a negligible adsorption were selected for the full testing. Then the products were solubilized in brine and injected in Berea core plugs or slim tubing at different fluid saturation (fully brine and at residual oil saturation). The production curves obtained were compared to a passive tracer (NaI) previously injected and the retention time difference was evaluated. Consistent differences in the production curves were observed among the products, revealing their potential use in formation characterization. The method allowed the evaluation of the travelling performance inside the cores of the different potential tracers. In particular, the different affinity to oil presence, correlated to the peculiar molecular lipophilicity revealed a potential application as partitioning tracers. The measurement of the bulk partition coefficients, represented by the concentration of the tracers between the two phases (K = Coil/Cwater) allowed estimation of the oil present and results were in reasonable agreement with the experimentally measured oil content (Sor). A limit observed in proper application of the tracer procedures is often associated to the efficiency in detection in production fluids. The classes of products applied show a more efficient detection phase, which is critical in tracers’ campaign, allowing a more precise evaluation of the production curves suitable for better modelling and parameter estimation. The conditions of application (e.g fluids, temperature, and lithology) should be nevertheless carefully evaluated in a lab examination before use in the field.

Abstract This paper highlights the solution, execution, and evaluation of the first 12.25″ application of hybrid bit on rotary steerable system in S-Shape directional application to drill interbedded formations with up to 25 % chert content in UAE land operations. The main challenge that the solution overcame is to drill through the hard chert layers while avoiding trips due to PDC bit damage nor drilling hour's limitation of TCI bit while improving the overall ROP and achieving the directional requirement. The solution package has demonstrated a superior ROP over rollercone bits, as well as improved PDC cutter durability and lower reactive torque leading to better steerability and stability which will be detailed in this paper. A significant contributor to such success was utilizing a new hybrid bit technology which incorporates the dual cutting mechanisms of both polycrystalline Diamond Compact (PDC) and rollercone bits. This allows a more efficient drilling by bringing the durability of the crushing action of rollercone to drill through hard interbedded lithology and the effectiveness of the shearing action of PDC cutters to improve ROP without sacrificing the toughness of the cutting structure edge. The proposed solution in combined with continues proportional rotary steering system managed to drill 4,670 ft through heterogeneous formation with chert nodules, with an average ROP of 38.29 ft\hr improving ROP by 15% and eliminating extra trips of utilizing roller cone bits to be able to drill though the chert nodules and avoid the PDC bit damage. Leading reduction in cost per foot by 35 %. Additionally, the hybrid bit exceed the expectation achieving 878 thousand of revolutions, with effective bearing and with the drilling cutting structure in a very good condition. Furthermore, the directional objectives were met with high quality directional drilling avoiding wellbore tortuosity. Such success was established through application analysis, specific formations drilling roadmaps and optimized drilling parameters in order to improve the overall run efficiency. The combination of roller cone and PDC elements in a hybrid bit designed to deliver better efficiency and torque stability significantly increased performance drilling the section in one single run, proven that heterogeneous formations can be drill.

The stringent structural requirements posed on aircraft engines, especially the high pressure turbine blades, result from the diversity of the extreme operational conditions they are subjected to. The accurate life assessment of the blades under these conditions therefore demands accurate analytical tools and techniques, and also an elaborate understanding of the operational conditions. Given the drive to reduce cost related to experimental testing, numerical approaches are often adopted to aid in the initial design stages. With recent advancement in numerical modelling, the simultaneous integration of the various numerical codes of fluid flow and structural analysis (otherwise known as fluid-structure interaction) is projected to provide reliable input into fatigue life prediction programs. This study adopts the numerical method of fluid-structure interaction to investigate the fatigue properties of the Aachen turbine test case. A load-time history obtained for the high stress monitor position is superimposed on that from a quasi-static FE solution, and used as input into a fatigue estimation tool. The low cycle fatigue (LCF) is estimated using the Basquin-Coffin-Manson correlation with corrections for mean stress and multi-axial fatigue effects. An FFT analysis of the fluctuating aerodynamic loads show signals with significant high frequency content. There is noticeable increased energy signal at the rotor inlet as compared to stator inlet. The stator inlet signals, however, are characterized by multiple resonances of frequency with lower energy content. By avoiding the resonances, the fatigue analysis predicts a safe design with a safety factor level of 3 for the rotor.

Steam generator tube rupture (SGTR) incidents, such as those, which occurred in various operating pressurized, water reactors in the past, are serious operational concerns and remain among the most risk-dominant events. Although considerable efforts have been spent to understand tube degradation processes, develop improved modes of operation, and take preventative and corrective measures, SGTR incidents cannot be completely ruled out. Under certain conditions, high releases of radionuclides to the environment are possible during design basis accidents (DBA) and severe accidents. The severe accident codes’ models for aerosol retention in the secondary side of a steam generator (SG) have not been assessed against any experimental data, which means that the uncertainties in the source term following an unisolated SGTR concurrent with a severe accident are not currently quantified. The accident management (AM) procedures aim at avoiding or minimizing the release of fission products from the SG. The enhanced retention of activity within the SG defines the effectiveness of the accident management actions for the specific hardware characteristics and accident conditions of concern. A sound database on aerosol retention due to natural processes in the SG is not available, nor is an assessment of the effect of management actions on these processes. Hence, the effectiveness of the AM in SGTR events is not presently known. To help reduce uncertainties relating to SGTR issues, an experimental project, ARTIST (AeRosol Trapping In a Steam generaTor), has been initiated at the Paul Scherrer Institut to address aerosol and droplet retention in the various parts of the SG. The test section is comprised of a scaled-down tube bundle, a full-size separator and a full-size dryer unit. The project will study phenomena at the separate effect and integral levels and address AM issues in seven distinct phases: Aerosol retention in 1) the broken tube under dry secondary side conditions, 2) the near field close to break under dry conditions, 3) the bundle far-field under dry conditions, 4) the separator and dryer under dry conditions, 5) the bundle section under wet conditions, 6) droplet retention in the separator and dryer sections and 7) the overall SG (integral tests). Prototypical test parameters are selected to cover the range of conditions expected in severe accident as well as DBA scenarios. This paper summarizes the relevant issues and introduces the ARTIST facility and the provisional test program which will run between 2003 and 2007.

Abstract Utilization of neural networks to solve physical problems has been receiving wide attention recently. These neural networks are commonly named physics-informed neural network (PINN), in which the physics are employed through the governing partial differential equations (PDEs). Traditional PINNs suffer from unstable performance when dealing with flow problems in highly heterogeneous domains. This work presents the applicability of the extended PINN (XPINN) method in solving heterogeneous problems. XPINN can create a full solution model to the solution of the governing PDEs by training the neural network on the PDEs and its constraints such as boundary and initial conditions, and known solution points. The heterogeneous problem is solved by performing domain decomposition, which divides the original heterogeneous domain into various homogeneous sub-domains. Each sub-domain incorporates its own PINN structure. The different PINNs are connected through interface conditions, allowing for information to communicate across the interfaces. These conditions include pressure and flux continuities. Various heterogeneous scenarios are implemented in this study to investigate the robustness of the proposed method. We demonstrate the accuracy of the XPINN model by comparing it with the ground truth solved from high-fidelity simulations. Results show a good match in terms of pressure and velocity with errors of less than 1%. Different interface conditions were tested, and it was observed that without the inclusion of pressure and flux continuities, the solver does not converge to the solution of interest. Sensitivity analysis was performed to explore the effects of the neural network architecture, the weights given to each loss term, and the number of training iterations. Results show that wide and shallow networks performed well due to avoiding the gradient vanishing issue that comes with deeper networks. In addition, balanced weights produced better accuracy in general. Moreover, more training iterations improved the accuracy of the results but at lower rates in later training stages. This paper presents XPINN to solve fluid flow in heterogeneous media. We demonstrate the robustness and accuracy of the proposed XPINN model by comparing it with the ground truth solutions in multiple heterogeneous cases. The model shows good potential and can be readily implemented in reservoir characterization workflow.

Abstract With the great improvement of computer performance, multi-physics and high-fidelity reactor numerical simulation has attracted widespread attention. The development of a three-dimensional fine-mesh coupled neutronics and thermal-hydraulics procedure mainly using the free open source C++ library OpenFOAM is presented in this research. The coupling codes are allowed to solve the coupled neutronic and thermal-hydraulic problem within the same one procedure for both steady-state and transient conditions, avoiding the data transmission between different programs. The coupling strategy among two physical fields is implemented in the same fully three-dimensional and fine mesh system, which eliminates numerical errors caused by the mapping of the grid. For the thermal-hydraulics, the built-in solid-fluid coupling conjugate heat transfer solver is applied for the calculation of the fluid mass, momentum, and energy equations, together with the solid energy equation to obtain the temperature distribution. The neutron diffusion equation is solved iteratively via the developed three-dimensional multi-group multi-region neutron diffusion solver to get the power distribution. The macroscopic cross-sections are pre-generated by the Monte Carlo code OpenMC and fitted as functions of temperature added in the neutron diffusion solver. The temperature distribution obtained by thermal-hydraulics calculation will change the macroscopic cross-sections and then impact the neutron diffusion calculation, while the power distribution gained from the neutronic calculation is transferred to the thermal-hydraulics calculation and is used as the heat source term. This coupling methodology are tested on a 3 × 3 PWR fuel pins model. The results show that all physical fields conform correct distribution regularity, illustrating the feasibility of the coupling methodology.

Abstract Subsurface uncertainty, inadequate offset wells correlation, and high investment cost are some of the biggest drilling challenges in any frontier environment or wild cat exploration wells. These challenges comes with inherent risk on people, environment, assets, and reputation. Mitigating these risks through contingency in the detailed well planning phase as well maximizing operational uptime and efficiency during the well delivery phase, greatly impact the outcome of the well. Digital tools and automation have been a cornerstone in the industry's latest tools to reduce personnel on the rig, as well as minimize downtime and inefficiency. A collaboration of experts between an Operator and Service company was formed during the well planning phase to evaluate the feasibility of an automation platform for a holistic drilling advisory platform that facilitates real time decision making based on downhole and surface data. An offset well study in the area showed that nearby wells experienced recurrence incidents of wellbore instability and downhole pore pressure uncertainty. Modeling iterations for dynamic and static drilling were simulated during pre-planning phase and optimized in real time based on actual downhole and surface data information. Real time models were compared against dynamic models such as Torque and Drag, Hole Cleaning, Pore pressure, ECD (Equivalent Circulating Density), ESD (Equivalent Static Density), and tripping speed (Swab, Surge, etc.). An automated directional drilling tool was run and compared to decisions made by the directional driller to improve the tool's decision-making process for predictive well trajectory parameters. Based on the resultant models, proactive advice was given to the rig in real-time to optimize the input parameters and reduce negative impact to well operation. For example, the practical, real-time visualization helped quickly identify a decreasing pore pressure trend and avoided resultant high overbalance while drilling the 17.5 in. × 22 in. section. The early warning alert allowed swift real time reaction sent to the rig, with mud weight subsequently decreased to 9.2 ppg, avoiding a potential risk of differential sticking stuck pipe incident due to high mud overbalance. Torque and Drag monitoring throughout the well accurately identified few instances of deviation from the trend and models, which detected an early sign of deteriorating wellbore condition which eventually led to a temporary stuck pipe event. Nevertheless, the pipe was freed, which demonstrate that the real time advisory helps in minimizing and avoiding the severe impact of the stuck pipe on the drilling operation. Automated advisory effectively delivered alerts on tight spots while drilling and casing running resulting in a faster 9-5/8 in. liner running in the deviated section. Tripping advisory mode and Real-time modelling of the swab-surge limits successfully allowed the team to avoid critical areas or swabbing events, which increased tripping speed where an opportunity was available and reduced tripping speed when risk of swab/surge was high avoiding well control/well loss events. The automated directional drilling tool increases in accuracy as the dogleg increased. The intelligent advice from the model got closest to the decisions taken by the directional driller, the closer the well got to the planned trajectory. These resulted in improvement and feedback for the pre-planning model such as target radius allowance, formation properties, and optimum drilling parameters. This work takes the first steps towards drilling automation and digital integration of insights and operation. The collaboration between operator and service company resulted in a successful deployment of an automation platform as a solution to manage and mitigate risks as well as optimize drilling operations in exploration wells.

A cold flow static rig test and computational fluid dynamics (CFD) analyses have been performed to verify the benefits of a modified “deflector” design to the blade air cooling feed system. The area of interest is the broach passage which is a space between the bottom of the blade fixing and the blade disk. Cooling flow enters into this region from the disk cavity and then exits upward into the blade internal cooling passages. Steady Navier-Stokes analyses of the cold flow static rig geometries were performed using the in-house code NS3D and the commercial code CFX v5.6. Due to the setup of the experimental rig, the numerical domain model with appropriate boundary conditions had to be carefully selected. Unstructured grids including wall prism layers combined with mesh adaptation were employed for both CFD codes on the baseline geometry. The commercial adaptation code OPTIMESH was used for NS3D while CFX employed its internal grid adaptation tool. No grid adaptation was necessary for the modified geometry. The pressure and mass flow measurements for the baseline and modified blade broach geometries demonstrated a reduction in losses for the new design. The CFD flow visualization showed the presence of a strong vortex in the broach for the baseline case with an accompanying low pressure zone. The modified broach design deflects the flow thus avoiding the formation of the strong vortex and low pressure zone. The CFD pressure distributions predicted the trends qualitatively. Quantitative comparisons of the CFD pressure distributions along broach walls were reasonable for the new design. For the baseline geometry, the CFD pressure drop is higher than measurements indicate. Modeling issues associated with a screen in the rig set-up is thought to be the source of the difference.

Abstract The variable geometry turbines (VGT) technology has been proved as beneficious for diesel engines turbocharging, becoming the standard for passenger car diesel engines when high boosting pressure and short transient response are pursued. It has not been until recent times that OEMs and turbocharger manufacturers are able to explore the advantages of VGTs in petrol engines. The high exhaust gases temperature and the low boost pressure prevented the introduction of petrol VGTs up to now. In modern direct injection petrol engines relevant fuel consumption benefits have been obtained from significant to moderate boosting pressure (thanks to downsizing strategies). This benefit joint with the advances in materials and turbocharger cooling technologies have fostered exploring the limits of VGT technology in petrol engines. Consequently, the 1-D and gas-dynamic modelling of turbocharged petrol engines for matching, benchmarking or analysis purposes has become a significantly more complex task. The reason is the energy loop interaction between VGT, petrol engine and compressor; which makes that all relevant system variables (boosting pressure, back-pressure, VGT inlet gas temperature, residuals, volumetric efficiency, etc) are coupled among them. In this case, a proper simulation strategy of the whole system with existing 1-D gas-dynamic codes, i.e.: avoiding excessive use of spurious-non-physical fitting coefficients, has not been enough explored either described in the literature yet. In addition, proper models of the turbocharger (both compressor and VGT) are more relevant now, since the VGT mechanism is a new variable with a first order influence. It can be destabilizing or tricking the whole system, depending on the engine operative conditions and turbo-model quality. In this paper, a systematic methodology, with physical perspective, for calibrating 1D codes of petrol engines with VGTs is clearly described. The methodology can be easily followed by other engineers or researchers in their modelling activities. In addition, the importance of the turbocharger sub-model for achieving successfully previous objectives is depicted. Standard characteristic maps used as look-up tables are shown to be a poor source of information when compared with pre-processed adiabatic and extrapolated maps. The focus is kept in low end torque at full load steady state and transient tip-in, for being the most challenging situations. Being, low-end torque simulation in steady state the baseline point for the transient simulation.