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The purpose of this paper is to investigate oil-gas slug formation in horizontal straight pipe and its associated pressure gradient, slug liquid holdup and slug frequency.

The abrupt change in gas/liquid velocities, which causes transition of flow patterns, was analyzed using incompressible volume of fluid method to capture the dynamic gas-liquid interface. The validity of present model and its methodology was validated using Baker’s flow regime chart for 3.15 inches diameter horizontal pipe and with existing experimental data to ensure its correctness.

The present paper proposes simplified correlations for liquid holdup and slug frequency by comparison with numerous existing models. The paper also identified correlations that can be used in operational oil and gas industry and several outlier models that may not be applicable.

The correlation may be limited to the range of material properties used in this paper.

Numerically derived liquid holdup and holdup frequency agreed reasonably with the experimentally derived correlations.

The models could be used to design pipeline and piping systems for oil and gas production.

The paper simulated all the seven flow regimes with superior results compared to existing methodology. New correlations derived numerically are compared to published experimental correlations to understand the difference between models.

This paper aims to discuss the general principles behind the microwave sensing and demonstrates the potential of cavity microwave resonator device in real-time monitoring for: environmental monitoring with the focus on wastewater pollution, a system for oil/gas/water content evaluation in a dynamic pipeline, a system for real-time determination of bacteria concentration and a method for non-invasive glucose determination.

Microwave sensing is a rapidly developing technology which has been successfully used for various industrial applications including water level measurements, material moisture content, in construction industry for non-invasive evaluation of structures and even in the healthcare industry for non-invasive real-time monitoring of glucose in diabetic patients. Novel microwave cavities designed and tested for specific applications are presented.

The paper provides experimental results of testing the novel microwave sensing systems in a range of industrial and healthcare applications and discusses the potential of these systems for real-time monitoring of processes and parameters.

The concept of real-time microwave sensing was successfully tested, but further experiments are required to account for possible interference mechanisms before it can be used commercially on a large-scale.

It is suggested that a novel approach to wastewater monitoring, namely using specially designed microwave cavity sensors, could lead to a successful development of an advanced platform capable of providing for a real-time detection of water content with superior sensitivity. Also, a system for real-time multiphase fluid composition monitoring is reported, which is essential for sustainable oil industry operation.

The paper illustrated the potential of microwave sensing as a real-time monitoring platform for a broad spectrum of commercial applications, with a focus on system developed by the authors, namely, for the monitoring of a multiphase fluid flow in a dynamic oil pipeline, for real-time monitoring of nutrients concentration in wastewater and for healthcare industry, in particular for real-time non-invasive determination of the glucose levels and bacteria concentration.

This paper aims to present an efficient IMPES algorithm based on a global model order reduction method, proper orthogonal decomposition (POD), to achieve the fast solution and prediction of two-phase flows in porous media.

The key point of the proposed algorithm is to establish an accurate POD reduced-order model (ROM) for two-phase porous flows. To this end, two projection methods including projecting the original governing equations (Method I) and projecting the discrete form of original governing equations (Method II) are respectively applied to construct the POD-ROM, and their distinctions are compared and analyzed in detail. It is found the POD-ROM established by Method I is inapplicable to multiphase porous flows due to its failed introduction of fluid saturation and permeability that locate on the edge of grid cell, which would lead to unphysical results.

By using Method II, an efficient IMPES algorithm that can substantially speed up the simulation of two-phase porous flows is developed based on the POD-ROM. The computational efficiency and numerical accuracy of the proposed algorithm are validated through three numerical examples, and simulation results illustrate that the proposed algorithm displays satisfactory computational speed-up (one to two orders of magnitude) without sacrificing numerical accuracy obviously when comparing to the standard IMPES algorithm that without any acceleration technique. In addition, the determination of POD modes number, the relative errors of wetting phase pressure and saturation, and the influence of POD modes number on the overall performances of the proposed algorithm, are investigated.

1. Two projection methods are applied to establish the POD-ROM for two-phase porous flows and their distinctions are analyzed. The reason why POD-ROM is difficult to be applied to multiphase porous flows is clarified firstly in this study. 2. A highly efficient IMPES algorithm based on the POD-ROM is proposed to accelerate the simulation of two-phase porous flows. 3. Satisfactory computational speed-up (one to two orders of magnitude) and prediction accuracy of the proposed algorithm are observed under different conditions.

The purpose of this paper is to design an oil-air lubrication system with low temperature rise, vibration and noise simplifies the spindle configuration. The oil-air lubrication unit is a key component for high-speed grinding machine tools. The development of oil-air lubrication unit suitable for high/ultrahigh rotational speed is a daunting task owing to the lubrication challenges.

This paper emphasizes three main issues: the analysis of oil-air two-phase flow for tradition oil-air lubrication unit with the simulation method; the design of new oil-air lubrication unit for the high/ultrahigh-speed grinding machine tools and the comparative experiment research of tradition and new oil-air lubrication unit. The optimum structure parameters that create the optimum flow pattern and operating conditions resulting in low temperature increase, vibration and noise of oil-air lubricated spindle can be achieved by the simulation method and experiments.

The simulation and experimental results show that new oil-air lubrication unit lubricating a high speed electric spindle has a better performance with a small temperature increase and vibration, which means that our proposed method is an effective design method for oil-air lubrication system.

A design method suitable for high-speed oil-air lubrication unit is proposed. New oil-air lubrication unit is expected to apply for high/ultrahigh rotational speed grinding machine tools.

The purpose of this paper is to enhance the understanding about how energy supply chains work to build resilience against exogenous security threats and thereafter what support mechanisms should be introduced or improved by the European Union.

Five case studies and data collection from multiple sources is used to understand what exogenous security threats could lead to the disruption of oil and gas flows to Europe, how energy companies, from a supply chain perspective, are working to manage these threats and finally, how the EU may coordinate the security of the energy sector in collaboration with supply chain companies.

Results show that today, oil and gas supply chains have in place a good combination of disruption strategies, including portfolio diversification, flexible contracts, transport capacity planning and safety stocks. The most relevant security threats the companies fear, include hijacking of vessels (sea piracy), but also terrorism, and wars. Finally, the study highlights that the European Union has built a comprehensive portfolio of strategies to deal with scarcity of oil and gas resources. However, these approaches are not often synchronized with supply chain strategies.

The paper provides guidance for supply chain managers dealing with critical suppliers located in conflict environments. The paper recommends that supply chain managers fine tune their strategies in coordination with governmental actions in foreign politics, dependence reduction and crisis management. This may be achieved by closer communication with governments and potentially through the creation of a pan-European sector alliance.

Previous research discusses the topic of supply chain resilience and supply chain risk management. However, none of these studies report on exogenous security threats and disruption strategies of oil and gas supply chains. At the same time, previous research lacks detailed studies describing the interaction between governments and energy supply chains.

As a kind of NP-hard combinatorial optimization problem, pipe routing design (PRD) is applied widely in modern industries. In the offshore oil and gas industry, a semi-submersible production platform is an important equipment for oil exploitation and production. PRD is one of the most key parts of the design of semi-submersible platform. This study aims to present an improved ant colony algorithm (IACO) to address PRD for the oil and gas treatment system when designing a semi-submersible production platform.

First, to simplify PRD problem, a novel mathematical model is built according to real constraints and rules. Then, IACO, which combines modified heuristic function, mutation mechanism and dynamical parameter mechanism, is introduced.

Based on a set of specific instances, experiments are carried out, and the experimental results show that the performance of IACO is better than that of two variants of ACO, especially in terms of the convergence speed and swarm diversity. Finally, IACO is used to solve PRD for the oil and gas treatment system of semi-submersible production platform. The simulation results, which include nine pipe paths, demonstrate the practicality and high-efficiency of IACO.

The main contribution of this study is the development of method for solving PRD of a semi-submersible production platform based on the novel mathematical model and the proposed IACO.

The analysis of lubricating properties and efficiency is important for aviation high-speed gear. So far, the project of lubricating properties and efficiency are processing under the condition of a given lubricating state, which is still depending on practical experience. This paper aims to mostly focus on the analysis of given lubricating state but lost sight of the relevance of lubrication parameters and lubricating state, which not only makes the analysis of aviation high-speed gear transmission and efficiency fail to trace to practical situation but also has an adverse effect on the reliance and validity of the project.

Based on this, the numerical model of spraying oil and oil film spreading is established, and the quantitative relationship between spray lubrication parameters and spreading characteristics of oil film is studied. According to the geometric and mechanical conditions of meshing points and taking the influence of rich-oil/starved-oil lubrication and roughness of teeth surface into consideration, corrected film thickness under condition of elasto-hydrodynamic lubrication and lubricating state of mesh points are analyzed. On this basis, power consumption and efficiency of gear transmission are also calculated by figuring out the solid friction and oil friction separately.

Through the research of this thesis, the effect of friction power consumption and efficiency with lubrication parameters is discussed. The effect of lubrication parameters on friction power consumption and efficiency of gear is complex. With the increase of spreading film thickness and film length, the frictional power consumption is less and the efficiency is higher.

This work provides a systematic technological approach to lubrication design and efficiency calculation of aviation high-speed gear transmission, which has remarkable engineering significance for the accurate lubrication design of the aviation mechanical parts.

According to the “strategic focus and future orientation” principle of the integrated reporting (<IR>) framework, <IR> should provide information useful to support investors in assessing the future financial performance of organizations. This study aims to support the operationalization of this function by improving the forward-looking orientation of the integrated report.

Basing on the backward- and forward-looking disclosure in <IR> and the dynamic resource-based view (DRBV), this study develops an explorative case study building a quantitative simulation model based on an integrated report.

This study provides useful insights into how operationalizing the <IR> “future orientation” and obtaining more quantitative information on the organization’s capacity to create value in the future by applying DRBV and quantitative simulation modeling.

The article presents one case study to explore the method suggested to improve the <IR> forward-looking orientation. Additional case studies applying the same research design should be certainly useful to refine the method.

Supporting the <IR> forward-looking orientation, this study provides additional information for the decision-making process of investors, thus contributing to the efficient and productive allocation of capital.

Few studies have investigated forward-looking information in integrated reports, highlighting the existence of an “information gap” referred to such disclosure. Overcoming these previous results, the study provides useful insights on how to improve the <IR> forward-looking orientation.

Pricing of natural gas in India suffers from asymmetry because of the presence of limited suppliers having byzantine contracts. The oligopolistic market combined with price regulation results in welfare losses, and market failure. We argue that for the sake of long-term development of natural gas sector in fast developing economies like India, the long-run marginal cost (LRMC) seems to be the most suitable pricing policy. In the case analysis, we present a theoretical framework of calculating LRMC while acknowledging that the conditions necessary for a ‘first-best world’ rarely exist. We conclude that it is very much possible to gradually move from the existing ad-hoc pricing mechanism to a more robust LRMC regime that takes into account not just the production cost but also a scarcity premium as well as any externalities resulting from the natural-gas fuel cycle. The outcome based on our model compares very well with the one from the Rangarajan Committee's formula that got the government's nod recently for fixing of price of indigenously produced natural gas, to be effective from 01st April 2014.

This paper aims to design a single and double throat oil groove structure, which can reduce the drag torque of the wet clutch.

A three-dimensional simulation model was established herein using the computational fluid dynamics method. The influence of oil groove structure on the oil film flow field and the drag torque is obtained by a simulation.

Compared with the traditional radial oil groove, the results show that the single throat oil groove structure reduces the drag torque by about 24.59%; the double throat oil groove reduces the drag torque by about 47.27%. As the speed difference increases, the average temperature rise of the oil film of the double throat oil groove is 4°C lower than that of the single throat oil groove, indicating that it has good heat dissipation performance. The analysis results were verified by experimental results.

In this paper, the radial oil groove is taken as the reference object, and the structure of the oil groove is designed and improved. The simulation analysis and experiment verify the rule of the influence of the oil groove structure on the drag torque, which provides a new design idea for reducing the drag torque of wet clutch.