Search results

1 – 10 of 39
To view the access options for this content please click here
Article

Zhaoju Qin, Chenheng Yuan, Yanpeng Yuan and Yuanyuan Huang

A free-piston engine (FPE) is an unconventional engine that abandons the crank system. This paper aims to focus on a numerical simulation for the lubricating…

Abstract

Purpose

A free-piston engine (FPE) is an unconventional engine that abandons the crank system. This paper aims to focus on a numerical simulation for the lubricating characteristics of piston rings in a single-piston hydraulic free-piston engine (HFPE).

Design/methodology/approach

A time-based numerical simulation program was built using Matlab to define the piston motion of the new engine. And a lubrication mode of piston rings was built which is based on the gas flow equation, hydrodynamic lubrication equation and the asperity contact equation. The piston motion and the lubrication model are coupled, and then the finite difference method is used to obtain the piston rings lubrication performances of the FPE. Meanwhile, the lubrication characteristics of the new engine were compared with those of a corresponding conventional crankshaft-driven engine.

Findings

The study results indicate that compared with the traditional engine, the expansion stroke of the HFPE is longer, and the compression stroke is shorter. Lubrication oil film of the new engine is thicker than the traditional engine during the initial stage of compression stroke and the final stage of the power stroke. The average friction force and power of the hydraulic free piston engine are slightly lower than those of the traditional engine, but the peak friction power of the FPE is significantly greater than that of the traditional engine. With an increase in load, the friction loss power and friction loss efficiency decrease, and with a decrease in equivalence ratio, the friction power loss reduces, but the friction loss efficiency decreases first and then increases.

Research limitations/implications

In this paper, only qualitative analysis was performed on the tribological difference between conventional crankshaft engine and HFPE, instead of a quantitative one.

Practical implications

This paper contributes to the tribological design method of HFPE.

Social implications

No social implications are available now, as the HFPE is under the development phase. However, the authors are positive that their work will be commercialized in the near future.

Originality/value

The main originality of the paper can be introduced as follows: the lubrication and friction characteristics of the new engine (HFPE) were investigated and revealed, which have not been studied before; the effect of the HFPE’s special piston motion on the tribological characteristics was considered in the lubrication simulation. The results show that compared with the traditional crankshaft engine, the new engine shows a different lubrication performance because of its free piston motion.

Details

Industrial Lubrication and Tribology, vol. 69 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

To view the access options for this content please click here
Article

K.S. Reddy, En Xie and Yuanyuan Huang

Drawing attention to the significant number of unsuccessful (abandoned) cross-border merger and acquisition (M&A) transactions in recent years, the purpose of this paper…

Abstract

Purpose

Drawing attention to the significant number of unsuccessful (abandoned) cross-border merger and acquisition (M&A) transactions in recent years, the purpose of this paper is to analyze three litigated cross-border inbound acquisitions that associated with an emerging economy – India, such as Vodafone-Hutchison and Bharti Airtel-MTN deals in the telecommunications industry, and Vedanta-Cairn India deal in the oil and gas exploration industry. The study intends to explore how do institutional and political environments in the host country affect the completion likelihood of cross-border acquisition negotiations.

Design/methodology/approach

Nested within the interdisciplinary framework, the study adopts a legitimate method in qualitative research, that is, case study method, and performs a unit of analysis and cross-case analysis of sample cases.

Findings

The critical analysis suggests that government officials’ erratic nature and ruling political party intervention have detrimental effects on the success of Indian-hosted cross-border deals with higher bid value, listed target firm, cash payment, and stronger government control in the target industry. The findings emerge from the cross-case analysis of sample cases contribute to the Lucas paradox – why does not capital flow from rich to poor countries and interdisciplinary M&A literature on the completion likelihood of international takeovers.

Practical implications

The findings have several implications for multinational managers who typically involve in cross-border negotiations. The causes and consequences of sample cases would help develop economy firms who intend to invest in emerging economies. The study also offers some implications of M&A for telecommunications and extractive industries.

Originality/value

Although a huge amount of extant research investigates why M&A fail to create value to the shareholders during the public announcement and post-merger stages, there is a significant dearth of research on the causes and consequences of delayed or abandoned national and international deals. The paper fills this knowledge gap by discussing an in-depth cross-case analysis of Indian-hosted cross-border acquisitions.

Details

Journal of Organizational Change Management, vol. 29 no. 6
Type: Research Article
ISSN: 0953-4814

Keywords

To view the access options for this content please click here
Article

Zhaohui Huang and Yuanyuan Song

This paper presents a robust numerical model for dealing with temporary instabilities which occur in the numerical analysis of steel structures under fire conditions. The…

Abstract

This paper presents a robust numerical model for dealing with temporary instabilities which occur in the numerical analysis of steel structures under fire conditions. The model adopts the combined static-dynamic solution procedure to model ‘snap-through’ behaviour of industrial steel portal frame in fire. This new method allows solution procedure automatically switch between static and dynamic approaches, with the objective mainly for overcoming a transitory stage of instability in structural modelling. The current model is computationally very efficient compared to conducting full dynamic analysis of the structures for the whole duration of fire. The method could easily be applied for modelling composite and reinforced concrete buildings under fire conditions. The snap-through instability of the pitched portal frame has been modelled successfully by the new procedure. The method could provide a very useful modelling tool for the perform-based fire safety design of industrial buildings, as a much more realistic alternative to the highly simplified design methods which are currently in use.

Details

Journal of Structural Fire Engineering, vol. 3 no. 3
Type: Research Article
ISSN: 2040-2317

Keywords

Content available

Abstract

Details

Journal of Organizational Change Management, vol. 29 no. 6
Type: Research Article
ISSN: 0953-4814

Content available

Abstract

Details

Open House International, vol. 45 no. 4
Type: Research Article
ISSN: 0168-2601

To view the access options for this content please click here
Article

Xu Huang and Yuanyuan Gu

Compared to other areas in China, Chaoshan region in Guangdong province has a more developed clan system set within a rural landscape. This paper aims to explore the…

Abstract

Purpose

Compared to other areas in China, Chaoshan region in Guangdong province has a more developed clan system set within a rural landscape. This paper aims to explore the relationship between the social structure (family–clan) and spatial form (housing settlement) of clan-organized rural China to understand the spatial form represented by “family and clan.”

Design/methodology/approach

By examining Dongli village and Huayao village, this paper outlines the typical path of spatial representation: dwelling of individual’s core family → mansion of the big family → settlement of a single clan → co-settlement of several clans. Moreover, it identifies three critical elements of the spatial representation: prototype (the spatial representation of the etiquette system); order (a hierarchical space set by the patriarchal system); and boundary (constructed on both physical and mental facts).

Findings

All elements indicate that descendants of migrants from the North maintain their self-identity and discipline clan members by planning the ideal space.

Research limitations/implications

The findings contribute to the ongoing discussions regarding how local cultural and historical experiences can influence renewed designs of traditional settlement areas (Aksulu and Eryildiz, 2003) and how digital means can facilitate updating designs of traditional buildings (Han et al., 2017). Such planning and design should involve greater public participation, considering the impact on residents’ daily lives (Pandya, 2005).

Originality/value

This paper contributes to the understanding of the relationship between cultural values and the spatial form of residential settlements in Chinese history.

To view the access options for this content please click here
Article

Yu Li, K.S. Redding and En Xie

Given that several publicly announced international merger and acquisition deals have been abandoned in recent years, the purpose of this paper is to present a synthesis…

Abstract

Purpose

Given that several publicly announced international merger and acquisition deals have been abandoned in recent years, the purpose of this paper is to present a synthesis of influential articles that examine organizational characteristics of cross-border acquisition transactions. The synthesis is framed through general traits and resources, learning and prior acquisition experience, and top-level management and governance attributes. Specifically, the paper conceptualizes key organizational attributes influencing the propensity of cross-border negotiations, and the most common characteristics and post-deal effects by illustrating several case examples from around the world.

Design/methodology/approach

Owing to fairness and integrity principles of the literature survey studies, the paper adopts an exploratory review design to present a synthesis of several influential articles published in strategy, international business and corporate finance journals. Since case method and storytelling are the best qualitative approaches to conceptualizing extant theoretical contributions, a number of case examples—successful, delayed and abandoned—from around the world have been discussed by leveraging the case information from archival sources.

Findings

Drawing on resource-based view, organizational learning, upper echelons and agency theory perspectives, the paper underscores three observations. First, organizational characteristics such as firm age, firm size, ownership structure, slack resources, marketing resources, technological intensity, export intensity and business group affiliation have different impacts on the propensity of publicly announced cross-border deals. Second, firm’s prior acquisition experience and firm’s acquisition experience in the target country have positive or moderating effects on the success of a cross-border merger. Third, top-level management characteristics such as CEO foreign nationality and CEO international career experience, and governance characteristics such as board size, the number of independent directors and directors with overseas experience, have mixed effects on the incidence of cross-border acquisitions.

Practical implications

The paper puts forth several recommendations for top-level managers participating in cross-border acquisition negotiations, such as learning from peers in the same industry, learning from predecessors in the target country and learning from failure negotiations in the same industry and other industries.

Originality/value

Nested within the organizational, international business strategy and corporate finance literature, the paper presents a synthesis of influential publications that study organizational characteristics affecting the propensity of cross-border acquisitions. The cases discussed in this paper are unique examples from around the world.

To view the access options for this content please click here
Article

Weiwei Wu, Xiaodiao Huang, Yuanyuan Li, Chenggang Fang and Xianhui Jiang

The screw extruder is applied in cement-three-dimensional (3D) printing. The cement paste flow in 3D printing is the typical Herschel–Bulkley fluid. To understand the flow…

Abstract

Purpose

The screw extruder is applied in cement-three-dimensional (3D) printing. The cement paste flow in 3D printing is the typical Herschel–Bulkley fluid. To understand the flow in the channel, the improved lattice Boltzmann method (LBM) is proposed.

Design/methodology/approach

For Herschel–Bulkley flow, an improved LBM is presented to avoid the poor stability and accuracy. The non-Newtonian effect is regard as a special forcing term. The Poiseuille flow is taken to discuss the detailed process of the method. With the method, the analytical solution and numerical solution are obtained and compared. Then, the effect of the initial yield stress on the numerical solution is both explored by the shear-thickening fluid and the shear-thinning fluid. Moreover, the variations of the relative errors under different lattice nodes and different power-law indexes are analyzed. Finally, the method is applied into the simulation of the flow in the extruder of cement-3D printing.

Findings

The results show that the improved method is effective for Herschel–Bulkley fluids, which can simulate the flow in the extruder stably and accurately.

Practical implications

The simulation can contribute to understand the cement paste flow in the screw extruder, which helps to optimize the structure of the extruder in the following periods.

Originality/value

The improve method provide a new way to analyze the flow in the extruder of cement-3D printing. Also, in the past research, LBM for Herschel–Bulkley fluid is ignored, whereas the study can provide the reference for the numerical simulation.

Details

Rapid Prototyping Journal, vol. 25 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

To view the access options for this content please click here
Article

Guomin Wang, Yuanyuan Wu, Haifu Jiang, Yanjie Zhang, Jiarong Quan and Fuchuan Huang

The purpose of this paper is to use the wavelet neural network and genetic algorithm to study the effects of polyalphaolefin, TMP108 and OCP0016 on the kinematic…

Abstract

Purpose

The purpose of this paper is to use the wavelet neural network and genetic algorithm to study the effects of polyalphaolefin, TMP108 and OCP0016 on the kinematic viscosity, viscosity index and pour point of lubricating oil.

Design/methodology/approach

Wavelet neural network is used to train the known samples, test the unknown samples and compare the obtained results with those obtained with a traditional empirical formula.

Findings

It is found that the wavelet neural network prediction value is closer to the experimental value than the traditional empirical formula calculation value.

Originality/value

The results show that the wavelet neural network can be used to study the physical and chemical indexes of lubricating oil.

Details

Industrial Lubrication and Tribology, vol. 72 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

To view the access options for this content please click here
Article

Wei Wei, Jun Chang, Qingjie Huang, Qiang Wang, Yuanyuan Liu and Zengguang Qin

As measurement results of optical gas sensors are constantly affected by the pressure of a target gas, approaches must be taken to modify the results. The purpose of this…

Abstract

Purpose

As measurement results of optical gas sensors are constantly affected by the pressure of a target gas, approaches must be taken to modify the results. The purpose of this paper is to compare the traditional measurement method with the new measurement system. At the same time, measurement results of the two systems under different pressures are presented for comparison of the detection performance.

Design/methodology/approach

A theoretical model of line shape function and its impact on the measured results is presented, which is based on direct absorption and wavelength modulation spectroscopy (WMS) for gas concentration detection under different pressures. Methods of linear fitting and result modification have been illustrated and compared. A new testing system with the result modification method used for water vapor concentration detection under different pressures between 1 and 7 atm is applied. With an additional pressure sensor placed in the gas cell and calibration performed, relationships between the amplitude of the second harmonic and concentration of the target gas under different pressures can be obtained.

Findings

Amplitude detection can be used for concentration detection regardless of the change in pressure for the method of direct absorption. Although, WMS with second harmonic detection is not enough. Two methods are presented and compared with WMS under different pressures. Moreover, the result modification method shows better performance as computation is significantly reduced.

Originality/value

The comparison between linear fitting and the result modification method with WMS under different pressures is firstly presented. At the same time, a new testing system with better performance for water vapor concentration detection under different pressures is presented as well.

Details

Sensor Review, vol. 37 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

1 – 10 of 39