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Rising energy costs and potential scarcity are driving energy reduction initiatives in manufacturing companies. The reduction in energy use is complementary to the classic lean production philosophy and the lean and green literature implies that reducing energy waste supports lean objectives. The purpose of this paper is to examine this perceived positive correlation and identify the impact level of energy reduction of lean product flow.

To achieve this, published case studies and practices from interview were gathered and categorised against a waste management hierarchy.

Energy reduction activities implicitly reduce waste which is compatible with the lean waste objective, however, when applying the waste hierarchy principle to energy efficiency practice, lean product flow is progressively constrained or compromised towards the lower levels of the hierarchy.

The hierarchical classification seeks to communicate how reported energy efficiency improvements will/will not impact on flow. The research focuses on the modification of existing discrete part production facilities towards greater energy efficiency and neglects alternative production technologies and new build. The results suggest that as manufacturers seeking to be more energy efficient move away from preventative actions to more reduce and reuse actions then production flexibility could become restricted and the design of production facilities make re-think the fast, linear and short flow of product.

Examples of industrial practices are provided to show the implications of energy reduction practice on production flow.

Categorises the relationship between classic lean and industrial low-energy initiatives to provide insight to how higher energy cost could impact on production.

The purpose of this study is to determine the cavitation flow characteristics of the high-pressure differential control valve. The relationship between cavitation, flow coefficient and spool angle is obtained. By analyzing the relationship between different spool angles and energy loss, the energy loss at different spool angles is predicted.

A series of numerical simulations were performed to study the cavitation problem of a high-pressure differential control valve using the RNG k–e turbulence model and the Zwart cavitation model. The flow states and energy distribution at different spool angles were analyzed under specific working conditions.

The cavitation was the weakest when the spool angle was 120° or the outlet pressure was 8 MPa. The pressure and speed fluctuations of the valve in the throttle section were greater than those at other locations. By calculating the entropy production rate, the reason and location of valve energy loss are analyzed. The energy loss near the throttling section accounts for about 92.7% of the total energy loss. According to the calculated energy loss relationship between different regions of the spool angle, the relationship between any spool angle and energy loss in the [80,120] interval is proposed.

This study analyzes the cavitation flow characteristics of the high-pressure differential control valve and provides the law of energy loss in the valve through the analysis method of entropy. The relationship between spool angle and energy loss under cavitation is finally proposed. The research results are expected to provide a theoretical basis for the optimal design of valves.

The purpose of this study is to investigate the coherent structures of pulsed opposing jets by large eddy simulation (LES) model and proper orthogonal decomposition (POD) snapshot method. Flow pulsation as an active flow control method is considered for the enhancement of transport phenomena in impinging jets. The effect of flow pulsation parameters such as pulsation signal shape and frequency on the vortical coherent structures, the energy content of primary modes and their variation are studied numerically.

In this study, flow field of turbulent pulsating opposing jets has been simulated using LES. The result of the simulation in different time steps (snapshots) are stored and POD is applied on the snapshots. In this study, the POD method and calculation of spatial modes has been done using OpenFOAM, and time coefficients have been calculated using a MATLAB code.

The results of this study show that the flow excitation has a great effect on the coherent structure formation and the energy containment of fundamental modes of the flow. When the flow was excited by a harmonic sinusoidal or step function, the turbulent kinetic energy accumulated in the set of primary modes. On the other hand, the pulsed opposing jets had more regularity compared to the steady jets. The shapes, patterns and energy values of dominant modes depended on the inlet pulsation signal. An increase in pulsation frequency leads to an augmentation in energy content of the primary modes.

The predictions may be extended to include various pulsation conditions such as: various amplitudes, Reynolds number and aspect ratio.

The results of this study are a valuable source of information for active control of transport phenomena in opposing jet configurations which is used in different industrial applications such as cooling, combustion, reactors, heating and drying processes.

In this study, the coherent structures and energy content of primary modes was studied for the first time by LES model and POD snapshot method and a comprehensive discussion on numerical results is provided.

China is a major energy import powerhouse, its trade deals have significant impact on international energy trade and global energy markets. The purpose of this paper is to explore the role of energy in China’s preferential trade agreements (PTAs) and their impact on Chinese imports of oil, gas and coal.

An extended trade gravity model framework is applied to explore the dynamics of China’s annualized energy import flows from the 22 economies that have PTAs with it for the period 1995–2015.

The effect of PTAs on trade patterns varies across the product groups and agreement clauses. The dominant factor affecting trade flows of coal, crude oil and oil products is the average tariff level. Its impact is less significant for gas imports, which are more affected by policy arrangements represented by a PTA variable. The depth and scope of a PTA do not affect Chinese energy imports patterns.

This paper is focused on exploring the effect of China’s trade and foreign relations strategies on its energy imports through the prism of its PTAs. Estimating the direct impact of China’s initiatives in the areas of trade, investment, security, culture, etc., on its trade flows of energy products and other product groups using the methodological framework proposed in this study would contribute to better understanding of the issue.

The findings can assist both China and energy exporting countries that target Chinese market in better understanding the drivers of trade flows of energy products and design their PTA strategies accordingly.

This study applies the trade gravity model framework to assess the impact of specific components of preferential trade agreements – tariff reduction and depth and scope of agreement – on energy trade flows differentiated by product group.

The conception of a heat function, just like the stream function used in a laminar two dimensional incompressible flow field visualization, has been introduced to visualize the convective heat transfer or the flow of energy around a sphere when the sphere is either being cooled or heated by a stream of fluid flowing around it. The heat function is developed in a spherical polar coordinate and is used to generate the heat lines around the sphere. The heat lines essentially show the magnitude and direction of energy transfer around the sphere with and without the existence of a finite radial velocity at the surface. The steady state hydrodynamic field around the sphere is numerically obtained up to a maximum Reynolds number of 100 and the corresponding thermal field has been obtained by solving the steady state energy equation. The field properties thus obtained are utilized to form the heat function, which becomes an effective tool for visualization of convective heat transfer.

Aims to use simple ratios as sustainability indicators to evaluate the environmental intensity in local regions and industrial sectors. These ratios could be compared across regions and industrial sectors to give a comprehensive evaluation of sustainability.

A total of 16 industrial categories (agriculture, mining, food, fiber, pulp, chemical, coal and petrol, cement, steel, metal, non‐ferrous metals, construction, energy supply, transport, service, and commercial) were considered, using data from the national physical distribution census, the national and prefectural input‐output tables, and the comprehensive energy statistics for Japan in 1995. The objective environmental load items were carbon dioxide, nitric oxide, sulfuric oxide, and suspended particulate matter emissions.

The regions included all 47 Japanese prefectures and the data for each prefecture considered 16 industrial categories based on the national physical distribution census and national input‐output tables for 1995. The ratio of the primary energy supply to the total material input for service industries ranged from 0.1 to 0.5 TOE/10³ ton for the 47 prefectures.

Not all the variations in these sustainability indicators have yet been examined and there are probably other complicated relationships between sustainability and regional or industrial characteristics. More effort needs to be put into estimating eco‐efficiency or eco‐intensity, considering recycled energy or material utilization in order to develop a practical method of evaluating regional or industrial sustainability.

Several life cycle approaches used to quantify environmental efficiency related to energy and material flows were investigated as applications of life cycle tools in emerging markets, including the service industry and public sector.

The novelty of the investigation lies in analyzing detailed energy flow characteristics and in combining energy flow and material flow. Another objective of this paper is to present a current case‐study experience in one type of eco‐intensity analysis for Japanese service industries.

This paper considers a perspective on particulate matter as being formed from closed loops of waveform energy flow, consistent with observations by de Broglie, Schrödinger and others and supported by recent research findings. It demonstrates that all experimentally verified findings of special relativity may be derived directly from such a model. It further shows a clear form of auto‐adaptive behaviour exhibited by such structures.

A generalised closed‐loop energy flow model is analysed from first principles.

Motion‐dependent time dilation, invariance of the measured speed of light, the Lorentz transformation, mass‐energy equivalence (E=mc²) and speed‐related increase in apparent mass all follow naturally from this structure. Given this view of matter objective invariance of the speed of light relative to all inertial states of motion is an unnecessary and insupportable assumption. A unique objective rest frame (subject to Hubble expansion of space) is identified. All elementary sub‐atomic particles owe their longevity to a non‐destructive state‐change response to energy input, referred to as “motion”. A radically new perspective on time is presented. A possible causal explanation for particle‐antiparticle asymmetry is identified.

Closed timelike curves are not a possibility. Further implications for all fields of physics are very extensive.

There is no conflict between superluminal technologies and causality. Over and above this, possible practical implications are too extensive to be enumerated.

The paper is totally original and of significant potential value in various respects.

Aging of the oil wells leads to a decrease in reservoir pressure and also to an increase in the water, gas and abrasive particles content. Therefore, there is a need for the oil pumps exploitation characteristics improvements. This paper aims to generate a valuable numerical model which will provide a useful tool to study various cases.

Computational fluid dynamics (CFD) analysis of the generation of so-called coherent structures of eddies and turbulence in the peripheral area of the vortex rotor mounted at the back side of centrifugal rotor was undertaken. After detailed analysis of the influence of the used turbulence models on the results, a hybrid turbulent model Detached Eddies Simulation (DES) was chosen as the most suitable.

Numerical control volume method with unsteady solver and DES turbulence model was proven to be valuable tool for flow analysis in the centrifugal pumps. Having in mind that DES turbulence model consumes much less computational time than large eddies turbulence model, this is a very useful fact that resulted from this research.

The proven numerical model is robust and reliable enough to become a standard method in simulating flow and other physical phenomena occurring in centrifugal pumps and similar turbo machines. This makes it possible to easily research different factors that influence their performances.

Comprehensive experimental and CFD study was performed which made it possible to conduct detailed validation and verification of described CFD model.

This paper aims to figure out the relationship between energy consumption flow from a new perspective of embodied energy inventory index (EEII) and regional economic growth.

The input-output approach has been applied to calculate embodied energy inventory (EEI) and EEII using the data of 25 economies. Meanwhile, cluster analysis and panel data modeling were applied to carry out detailed research.

The results of cluster analysis show that there is a roughly negative relationship between EEII and gross domestic product (GDP) per capita, although there are some exceptions, such as Russia and Taiwan (Province of China). Panel data model results provide further evidence that there is a negative relationship between EEII and GDP per capita. Population is an important productive factor in the regional economic development. The study showed a positive relationship between EEII and population. Therefore, energy consumption flow is closely related to regional economic development.

The value of this paper is to use EEI and EEII to comprehensively clarify the energy consumption flow. The advantage of EEII is that it can reflect the energy embodied in fixed assets and infrastructure.

This paper is aimed to study natural convection in enclosures with curved (concave and convex) side walls for porous media via the heatline-based heat flow visualization approach.

The numerical scheme involving the Galerkin finite element method is used to solve the governing equations for several Prandtl numbers (Pr_m) and Darcy numbers (Da_m) at Rayleigh number, Ra_m = 10⁶, involving various wall curvatures. Finite element method is advantageous for curved domain, as the biquadratic basis functions can be used for adaptive automated mesh generation.

Smooth end-to-end heatlines are seen at the low Da_m involving all the cases. At the high Da_m, the intense heatline cells are seen for the Cases 1-2 (concave) and Cases 1-3 (convex). Overall, the Case 1 (concave) offers the largest average Nusselt number ( Nur¯) at the low Da_m for all Pr_m. At the high Da_m, Nur¯ for the Case 1 (concave) is the largest involving the low Pr_m, whereas Nur¯ is the largest for Case 1 (convex) involving the high Pr_m.

Thermal management for flow systems involving curved surfaces which are encountered in various practical applications may be complicated. The results of the current work may be useful for the material processing, thermal storage and solar heating applications

The heatline approach accompanied by energy flux vectors is used for the first time for the efficient heat flow visualization during natural convection involving porous media in the curved walled enclosures involving various wall curvatures.