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Article
Publication date: 22 May 2007

Huanxin Lai, Yuying Yan and Keqi Wu

This paper aims to develop a numerical method for analysing the time‐dependent conjugate heat and fluid flows inside and around single bubbles rising in a hot liquid.

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Abstract

Purpose

This paper aims to develop a numerical method for analysing the time‐dependent conjugate heat and fluid flows inside and around single bubbles rising in a hot liquid.

Design/methodology/approach

The procedure combines the moving mesh method for flows in time‐dependent geometries and the zoned calculation algorithm for conjugate viscous flows. A moving axisymmetric boundary‐fitted mesh is used to track the deformable gas‐liquid interface, while conjugate flows in both gas and liquid sides are calculated by a two‐block zoned method. The interfacial stresses are employed to calculate the velocity value and to decide the time‐dependent bubble shape simultaneously. Governing equations for the rising velocity and acceleration of the bubble are derived according to the forces acting on the bubble.

Findings

A calculating procedure for time‐dependent conjugate heat and fluid flows inside and around a rising single bubble has been developed. The algorithm has been verified, and can be employed for further analysing heat, mass and momentum transfer phenomena and their relevant mechanisms.

Originality/value

The paper developed a method to obtain high fidelity results for the heat and fluid flow details in the vicinity of a time‐dependent moderately deformable rising bubble; the physically zero‐thickness of a gas‐liquid interface is guaranteed. The governing equations for the time‐dependent rising velocity and acceleration are derived.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 17 no. 4
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 1 October 2006

Y.Y. Yan and W.Z. Li

The paper aims at studying numerically a vapour bubble growth in uniformly superheated liquid.

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Abstract

Purpose

The paper aims at studying numerically a vapour bubble growth in uniformly superheated liquid.

Design/methodology/approach

Time dependent mathematical and numerical models are developed. Based on the Stefan boundary condition, the rate of heat transfer at the vapour‐liquid interface and the rate of bubble growth are calculated.

Findings

It is found that, at the initial stage of bubble growth, both the growth rate and the mean Nusselt number at bubble interface have the maximum values, then they decrease with time; the rate of bubble growth also has a significant effect on bubble deformation; the growth tends to keep the bubble at its initial shape. In addition, the growth and deformation of a vapour bubble have much influence on temperature propagation in the vicinity of the bubble‐liquid interface; the temperature wake at the rear of the bubble occurs at high Reynolds number but does not appear at low Reynolds number.

Originality/value

The paper is based on the authors' original work, focusing on the behaviour of a vapour bubble in uniformly superheated liquid–an issue of importance in the field of boiling and two phase flow.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 16 no. 7
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 8 August 2008

Y.Q. Zu, Y.Y. Yan, W.P. Shi and L.Q. Ren

The main objective of this work is to develop a boundary treatment in lattice Boltzmann method (LBM) for curved and moving boundaries and using this treatment to study numerically…

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Abstract

Purpose

The main objective of this work is to develop a boundary treatment in lattice Boltzmann method (LBM) for curved and moving boundaries and using this treatment to study numerically the flow around a rotating isothermal circular cylinder with/without heat transfer.

Design/methodology/approach

A multi‐distribution function thermal LBM model is used to simulate the flow and heat transfer around a rotating circular cylinder. To deal with the calculations on the surface of cylinder, a novel boundary treatment is developed.

Findings

The results of simulation for flow and heat transfer around a rotating cylinder including the evolution with time of velocity field, and the lift and drag coefficients are compared with those of previous theoretical, experimental and numerical studies. Excellent agreements show that present LBM including boundary treatment can achieve accurate results of flow and heat transfer. In addition, the effects of the peripheral‐to‐translating‐speed ratio, Reynolds number and Prandtl number on evolution of velocity and temperature fields around the cylinder are tested.

Practical implications

There is a large class of industrial processes which involve the motion of fluid passing rotating isothermal circular cylinders with/without heat transfer. Operations ranging from paper and textile making machines to glass and plastics processes are a few examples.

Originality/value

A strategy for LBM to treat curved and moving boundary with the second‐order accuracy for both velocity and temperature fields is presented. This kind of boundary treatment is very easy to implement and costs less in computational time.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 18 no. 6
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 7 September 2012

Yuying Xie, Liu Zheng and H.L. Amy Lau

The purpose of this study is to investigate reporting incentives for accounting conservatism in the context of asset and equity tunnelling and to provide empirical evidence that…

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Abstract

Purpose

The purpose of this study is to investigate reporting incentives for accounting conservatism in the context of asset and equity tunnelling and to provide empirical evidence that accounting conservatism can be reported for opportunistic reasons rather than efficiency reasons.

Design/methodology/approach

A cross‐sectional analysis of data from the period 2002 to 2004 is conducted.

Findings

This study provides empirical evidence that firms undertaking asset or equity tunnelling transactions report higher conservatism than firms undertaking other kinds of connected transactions. Further tests document a positive association between accounting conservatism and the private benefits gained by controlling shareholders from asset and equity tunnelling.

Originality/value

Contrary to the prevalent view that accounting conservatism signifies better quality accounting and benefits financial statement users, this study shows that accounting conservatism is influenced by institutional factors and the incentives of financial statement preparers. Researchers should exercise caution in interpreting higher accounting conservatism as an indication of better accounting information quality, especially in cross‐country research involving different institutions.

Details

Pacific Accounting Review, vol. 24 no. 2
Type: Research Article
ISSN: 0114-0582

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Article
Publication date: 10 August 2023

Yuying Wang and Guohua Zhou

As the complexity and uncertainty of megaprojects make it difficult for traditional management models to address the difficulties, this paper aims to design a performance…

120

Abstract

Purpose

As the complexity and uncertainty of megaprojects make it difficult for traditional management models to address the difficulties, this paper aims to design a performance incentive contract through IT applications, thereby promoting the formation of an information-based governance mechanism for megaprojects and facilitating the transformation and upgrading of the construction management model of megaprojects to informatisation.

Design/methodology/approach

This paper introduced IT applications into the performance assessment and used the proportion of IT applications replacing traditional manual management as a variable. It analysed different replacement ratios to obtain the optimal solution for the change of contractors behaviours and promote the optimal performance incentive for the informatisation in megaprojects.

Findings

The results show that under the condition of the optimal replacement ratio, achieving the optimal state of a mutual win-win situation is possible for the benefit of both sides. The counter-intuitive finding is that the greater the replacement ratio is not, the better, but those other constraints are also taken into account.

Originality/value

This study enriched the research of the performance configuration incentive from a practical perspective. It extended the research framework of IT incentive mechanisms in the governance of megaprojects from a management theory perspective. It clarified the role of IT applications in incentive mechanisms and the design process of optimal incentive contracts under different performance incentive states. The incentives made the contractors work harder to meet the owner's requirements, and it could improve the efficiency of megaprojects, thus better achieving megaproject objectives.

Details

Kybernetes, vol. 53 no. 12
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 25 October 2024

Luning Zang, Wenxiao Xiong, Yuying Liu and Ting Dai

To investigate the impact of cognition, emotion and other factors on positive customer engagement behaviors and to identify the differential formation processes and dynamic…

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Abstract

Purpose

To investigate the impact of cognition, emotion and other factors on positive customer engagement behaviors and to identify the differential formation processes and dynamic changes in these behaviors.

Design/methodology/approach

We used cognitive appraisals and coping theory as well as justice theory, to analyze comment data from the Xiaomi Community with natural language processing and binary logistic regression.

Findings

Our results indicate that cognition and emotion are unnecessary for positive customer engagement. Users expressing different cognitions and emotions exhibit varied positive engagement behaviors. The behavioral dimension was the most frequently combined, followed by the affective and cognitive dimensions. Managers should adopt material or spiritual incentives to encourage users with positive emotions and cognition to become loyal. Additionally, addressing comments with distributive justice cognition can promote positive customer engagement.

Originality/value

This study clarifies the complex interplay between cognition, emotion and customer engagement behaviors, providing actionable insights for brand managers to foster customer loyalty and positive customer engagement.

Details

Asia Pacific Journal of Marketing and Logistics, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-5855

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Article
Publication date: 18 October 2024

Yuying Wang and Guohua Zhou

The suppliers of experimental resources required in megaprojects are driven by short-term interests, presuming that participation in the digital platform would only increase their…

31

Abstract

Purpose

The suppliers of experimental resources required in megaprojects are driven by short-term interests, presuming that participation in the digital platform would only increase their inputs and fail to rapidly expand their revenue, resulting in their insufficient motivation to participate. This paper aims to design effective incentives for these suppliers exhibiting the aforementioned behaviour to drive them to participate and actively share their resources on the platform.

Design/methodology/approach

This paper develops incentives for applying the digital platform for experimental resource sharing by using a reverse induction approach to model and solve an incomplete information game. It compares the traditional experiment management mode and the new mode of applying the digital platform, taking the degree of sharing experimental resources on the platform as the variable and constructing three incentive models. By analysing these different degrees of sharing and the different experimental and informatisation capabilities of the suppliers, it could obtain the optimal incentive scheme for changes in sharing behaviour.

Findings

The results show that the designed incentives could increase the participation of suppliers in the platform and the number of their shared resources and make the benefits of both the supplier and the demand side reach the optimal state of a win-win situation. However, a higher degree of sharing by suppliers does not yield better results. In addition, the incentive coefficients for this degree should be set based on the suppliers’ different experimental and informatisation capabilities and the ratio of input cost-sharing, so as to avoid blind inputs from both supply and demand.

Originality/value

This study fills the research gap regarding incentives of the digital platform of experimental resource-sharing for megaprojects; it contributes to the body of knowledge by providing a quantitative perspective of understanding the experimental resource-sharing behaviour that motivates the usage of the digital platform. Furthermore, it reveals the incentive mechanism for application in different scenarios, and quantitative analysis is conducted to provide practical insights into promoting the new experiment management mode in megaprojects for more effective incentivisation.

Details

Engineering, Construction and Architectural Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0969-9988

Keywords

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Article
Publication date: 30 March 2021

Yuying An, Guangbiao Xu and Hua Shen

To have a better understanding of the heat transfer mechanisms in a sleeping bag and to investigate the factors influencing thermal resistance of a down sleeping bag.

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Abstract

Purpose

To have a better understanding of the heat transfer mechanisms in a sleeping bag and to investigate the factors influencing thermal resistance of a down sleeping bag.

Design/methodology/approach

The mechanism of heat transfer in a sleeping bag was discussed in this paper. The thermal resistances of 24 samples were investigated. Besides, the relation between fill weight and thermal resistance, and that between the air permeability of fabric and thermal resistance, as well as that between down filling rate and thermal resistance were analyzed.

Findings

The results showed that thermal resistances of samples varied from 0.35 to 0.8 m2 K/W. The fill weight was the most important factor of thermal resistance of sleeping bag and the relation between fill weight and thermal resistance matched well with cubic function. A multiple regression formula was proposed, which with thermal resistance as a dependent variable and with air permeability of fabric, down filling rate, fill weight as independent variables.

Originality/value

Thermal properties of a sleeping bag were analyzed through simplified basic unit under simplified environment conditions, which was necessary for building the first stage of systematic study of thermal performance of a sleeping bag.

Details

International Journal of Clothing Science and Technology, vol. 33 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

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Article
Publication date: 31 May 2022

Ye Li, Xue Bai, Bin Liu and Yuying Yang

In order to accurately forecast nonlinear and complex characteristics of solar power generation in China, a novel discrete grey model with time-delayed power term (abbreviated as

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Abstract

Purpose

In order to accurately forecast nonlinear and complex characteristics of solar power generation in China, a novel discrete grey model with time-delayed power term (abbreviated as TDDGM(1,1,tα) is proposed in this paper.

Design/methodology/approach

Firstly, the time response function is deduced by using mathematical induction, which overcomes the defects of the traditional grey model. Then, the genetic algorithm is employed to determine the optimal nonlinear parameter to improve the flexibility and adaptability of the model. Finally, two real cases of installed solar capacity forecasting are given to verify the proposed model, showing its remarkable superiority over seven existing grey models.

Findings

Given the reliability and superiority of the model, the model TDDGM(1,1,tα) is applied to forecast the development trend of China's solar power generation in the coming years. The results show that the proposed model has higher prediction accuracy than the comparison models.

Practical implications

This paper provides a scientific and efficient method for forecasting solar power generation in China with nonlinear and complex characteristics. The forecast results can provide data support for government departments to formulate solar industry development policies.

Originality/value

The main contribution of this paper is to propose a novel discrete grey model with time-delayed power term, which can handle nonlinear and complex time series more effectively. In addition, the genetic algorithm is employed to search for optimal parameters, which improves the prediction accuracy of the model.

Details

Grey Systems: Theory and Application, vol. 13 no. 1
Type: Research Article
ISSN: 2043-9377

Keywords

Available. Content available
Book part
Publication date: 23 June 2016

Abstract

Details

Essays in Honor of Aman Ullah
Type: Book
ISBN: 978-1-78560-786-8

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