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The velocity head is usually neglected in the energy equation for a pipeline junction when one-dimensional (1D) hydraulic transient flow is solved by method of characteristics. The purpose of this paper is to investigate the effect of velocity head on filling transients in a branched pipeline by an energy equation considering velocity head.

An interface tracking method is used to locate the air–water interface during pipeline filling. The pressured pipe flow is solved by a method of characteristics. A discrete gas cavity model is included to permit the occurrence of column separation. A universal energy equation is built by considering the velocity head. The numerical method is provisionally verified in a series pipeline and the numerical results and experimental data accord well with each other.

The numerical results show that some differences in filling velocity and piezometric head occur in the branched pipeline. These differences arise because the velocity head in the energy equation can become an important contributor to the hydraulic response of the system. It is also confirmed that a local high point in the profile is apt to experience column separation during rapid filling. Significantly, the magnitude of overpressure and cavity volume induced by filling transients at the local high point is predicted to increase with the velocity in the pipes.

The velocity head in the energy equation for a pipeline junction could play an important role in the prediction of filling velocity, piezometric head and column separation phenomenon, which should be given more attention in 1D hydraulic transient analysis.

Tip leakage vortex flow (TLV) is a common flow phenomenon in the axial-flow hydraulic machinery. High-efficiency simulation of TLV is still not an easy task because of the complex turbulent vortex-cavitation interactions. As an important basis of CFD, turbulence model directly affects the efficient computation of TLV. The purpose of this paper is to evaluate the newly developed MST turbulence model in predicting the TLV flows.

By using the MST turbulence model and the ZGB cavitation model, numerical simulations of the TLV generated by a NACA0009 hydrofoil were performed under the cavitation-free and cavitation conditions, and the results were compared with the available experimental data.

The important features of TLV are well captured by the MST-based simulation scheme, and the problem of under-predicting the cavitating TLV tube is well solved. Turbulent viscosity is reasonably adjusted in the TLV core regions, and the LES-like mode is activated, which is beneficial to obtain more turbulent information on the same URANS grids. The requirements of grid size and time step of the MST model are much lower than that of the LES method, thereby weighing a good balance between the simulation accuracy and computation cost.

The MST turbulence model is suitable for the high-efficiency simulation of the TLV flows, which can lay a good foundation for efficient engineering computations of the cavitating TLV in the axial-flow hydraulic machinery.

Rotating stall is an unsteady flow phenomenon that causes instabilities and low efficiency in pumps. The purpose of this paper is to investigate the rotating stall characteristics and unsteady behavior of stall cells in a centrifugal pump impeller at low flow rates.

A developed large eddy simulation with dynamic mixed nonlinear model is performed to evaluate the unsteady flow in a centrifugal pump impeller. The rotating stall flow field through the centrifugal pump impeller is analyzed under three typical flow rates. Frequency spectrum analysis are carried out on the series of pressure fluctuation to get the rotating stall characteristics. The size and intensity of stall cells are also analyzed using time-averaged vorticity and static pressure.

The rotating stall cell first occurs in the suction side of the blade and exhibits an obvious life cycle including decay mergence, shedding, growing and development with a low frequency. With the decrease of flow rate, the amplitude of pressure fluctuations in the impeller tends to be larger, the propagated speed of stall cells and rotating stall frequency tends to be smaller, but the number of cells remains unchanged. The size of stall cells increases as the flow rate decreases, but intensity changes is very little.

The rotating stall characteristics in a centrifugal pump impeller under low flow rates are presented first using a developed large eddy simulation approach.

This study aims to focus on the grid connected inverter.

The grid connected inverter for harmonic suppression was designed, the topological structure of the inverter and the design of LCL filter were analyzed, then a PIR controller was proposed and finally simulation and experiment were carried out.

The simulation results showed that the distortion rates of the 5th, 7th and 11th harmonics under PIR control were 0.14%, 0.13% and 0.06%, respectively, which were significantly lower than that under PI control. The system test results also showed that the current waveform under PI control was rough and total harmonic distortion (THD) content was 3.8%; under PIR control, the grid connected current waveform was relatively smooth, with fewer spikes and burrs, and the THD content was 1.9%, indicating that the harmonics were effectively suppressed.

The experimental results verify that the inverter and PIR controller designed in this study are effective for harmonic suppression. This work makes some contributions to the improvement of the effect of harmonic suppression and promotion of the better application of grid connected inverter.

High speed axial flow pumps are widely used in aircraft fuel systems. Conventional axial flow pumps often generate radial secondary flows at partial-load conditions which influence the flow structure and form a “saddle-shaped” region in the Q-H curve that can destabilize the operation. Thus, the “saddle-shaped” Q-H region must be eliminated. The paper aims to discuss these issues.

The swept stacking method is often used for radial flow control in turbo-machinery impeller blade design. Hence, this study uses the swept stacking method to design a high speed axial flow pump. The detached eddy simulation method and experiments are used to compare the performance of a swept blade impeller in a high speed axial fuel pump with the original straight blade impeller. Both the pump performance and internal flow characteristics are studied.

The results show separation vortices in the impeller with the straight blade design at partial-load conditions that are driven by the rotating centrifugal force to gather near the shroud. The swept geometry provides an extra force which is opposite to the rotating centrifugal force that creates a new radial equilibrium which turns the flow back towards the middle of the blade which eliminates the vortices and the “saddle-shaped” Q-H region. The swept blade impeller also improves the critical cavitation performance. Analysis of the pressure pulsations shows that the swept blade design does not affect the stability.

This study is the initial application of swept blades for axial flow liquid pumps. The results show how the swept stacking changes the radial equilibrium of the high density, high viscosity flow and the effects on the mass transfer and pressure pulsations. The swept blade effectively improves the operating stability of high speed fuel pumps.

Large eddy simulation (LES) is widely used in prediction of turbulent flow. The purpose of this paper is to propose a new dynamic mixed nonlinear subgrid‐scale (SGS) model (DMNM), in order to improve LES precision of complex turbulent flow, such as flow including separation or rotation.

The SGS stress in DMNM consists of scale‐similarity part and eddy‐viscosity part. The scale‐similarity part is used to describe the energy transfer of scales that are close to the cut‐off explicitly. The eddy‐viscosity part represents energy transfer of the other scales between smaller than grid‐filter size and larger than grid‐filter size. The model is demonstrated through two examples; one is channel flow and another is surface‐mounted cube flow. The computed results are compared with prior experimental data, and the behavior of DMNM is analyzed.

The proposed model has the following characteristics. First, DMNM exhibits significant flexibility in self‐calibration of the model coefficients. Second, it does not require alignment of the principal axes of the SGS stress tensor and the resolved strain rate tensor. Third, since both the rotating part and scale‐similarity part are considered in the new model, flow with rotation and separation is easily simulated. Compared with the prior experimental data, DMNM gives more accurate results in both examples.

The SGS model DMNM proposed in the paper could capture the detail vortex characteristics more accurately. It has the advantage in simulation of complex flow, including more separations.

The purpose of this paper is to provide a structured literature review (SLR) and systematic insight into logistics outsourcing research, in order to identify gaps in knowledge, and provide future research direction in the logistics outsourcing discipline.

This paper identifies and synthesises information from academic journals and examines research designs and methods, data analysis techniques, geographic locations, industry engagements, year of publication, publishers, university and author affiliations. A collection of online databases from 1991 to 2016 were explored, using the keywords “third-party”, “logistics” and “outsourcing” in their title and/or abstract, to deliver an inclusive listing of journal articles in this discipline area. Based on this approach, a total of 263 articles were found and data were derived from a succession of variables.

There has been a significant increase and concentration by researchers over the past 25 years focussing on logistics outsourcing. A need to implement best practice has been universally identified, owing to increasing global supply chain complexity. This analysis shows that only seven literature reviews were published in the logistics outsourcing discipline. Additionally, this study revealed that 42 per cent of the work in this field was found to be survey based and this trend in research indicates the development of the structural equation modelling and multi-criterion decision-making methods. Investigations between 2010–2012 and 2015–2016 accounted for 151 of the total 263 articles published. Finally, reverse logistics is an area that requires special attention.

This paper is limited to a review of academic articles obtainable from online databases, containing the words “logistics” and “outsourcing” in the title and/or abstract. Additionally, only papers from high quality, peer-reviewed journals were evaluated. Other academic sources such as books and conference papers were not included in this study.

This review will provide an increased understanding of the existing state of current research, trends and future research directions in the logistics outsourcing discipline.

The rapid growth of m-commerce and mobile marketing has flooded the users with homogeneous contents that raise little user interest making the users' browsing pattern on these contents aimless free browsing. However, the interface that presents the mobile marketing contents triggers much user attention, especially the layout. Without significant usability defects, the layout poses influences on the user's aesthetic experience. Identifying the layout attributes that affect user aesthetic preference is critical to the design of mobile marketing interfaces since they influence users' interaction intention, cognitive process, and decision-making.

In this paper, 6 layout attributes that quantify the aesthetic design of the interface layout and 3 eye-movement indicators that connect to human aesthetic preference were identified through literature research. An eye-tracking experiment measuring the 3 eye-movement indicators on 6 pairs of interface layout materials corresponding to the 6 layout attributes was conducted. The experiment was designed to mimic the free browsing context in mobile marketing. The materials were divided into Liked/Disliked preference groups according to the response of the subjects. Analysis of indicators on materials between the L/D groups shows that the attributes of balance, centricity, density, simplicity, and symmetry affect user aesthetic preferences.

Analysis of the attribute value levels shows that balance, centricity, and density are responsible for addressing users' aesthetic preferences for a disliked interface layout. The study suggests an attribute set for quantitatively optimizing the aesthetic design of mobile marketing system interfaces and provides evidence for the visual attention and cognitive process under the free browsing context.

The study contributes to the field both theoretically and practically: (1) it provides support for optimizing the interface layout of mobile marketing systems quantitatively from the aesthetic perspective. (2) It promotes the cognitive attention theory by providing evidence for the cognitive process of interacting with mobile marketing interfaces from the perspective of visual attention and cognitive fluency. (3) It expands the objects of visual perception from traditional or symbolic artworks (such as logos) to the abstract visual stimuli of interface layout. (4) It suggests an optimization tool of five quantification layout attributes for mobile marketing businesses and platforms to aesthetically improve their marketing interfaces to improve user experiences.

The purpose of this paper is to investigate how customer pressure influences green innovation in the context of Chinese third-party logistics (3PL) providers, and especially the role of organizational culture in moderating this relationship.

Based on survey data collected from 165 3PL providers in China, hierarchical moderated regression analysis was conducted to test the hypotheses.

Customer pressure is an important driver of green innovation amongst 3PL providers. Flexibility-oriented organizational culture strengthens the effect of this driving force, while control-oriented organizational culture weakens this force. Green innovation significantly contributes to financial performance and flexibility orientation strengthens this contribution, while control orientation weakens it.

This research examines the contingency effect of organizational culture in helping to resolve inconsistencies in the relationship between customer pressure and green innovation. Although the inconsistencies cannot be resolved completely, the research opens an avenue to explore other contingency factors or the possibility of a non-linear relationship.

3PL firms could undertake green innovation to satisfy customers’ environmental requirements. To develop their green innovation initiatives, managers should allow their employees greater autonomy and design (or re-design) operations procedures and regulations to be more flexible, thus enabling the diffusion of green innovation and avoiding or reducing the potential influence of control-oriented organization culture.

The study considers the conditional effect of organizational culture to reconcile the mixed results in the literature regarding the relationship between customer pressure and green innovation of logistics service providers.