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Article
Publication date: 1 June 2000

A. Savini

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community…

1146

Abstract

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 19 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 22 July 2019

Behnam Rafiei, Hamed Masoumi, Mohammad Saeid Aghighi and Amine Ammar

The purpose of this paper is to analyze the effects of complex boundary conditions on natural convection of a yield stress fluid in a square enclosure heated from below (uniformly…

Abstract

Purpose

The purpose of this paper is to analyze the effects of complex boundary conditions on natural convection of a yield stress fluid in a square enclosure heated from below (uniformly and non-uniformly) and symmetrically cooled from the sides.

Design/methodology/approach

The governing equations are solved numerically subject to continuous and discontinuous Dirichlet boundary conditions by Galerkin’s weighted residuals scheme of finite element method and using a non-uniform unstructured triangular grid.

Findings

Results show that the overall heat transfer from the heated wall decreases in the case of non-uniform heating for both Newtonian and yield stress fluids. It is found that the effect of yield stress on heat transfer is almost similar in both uniform and non-uniform heating cases. The yield stress has a stabilizing effect, reducing the convection intensity in both cases. Above a certain value of yield number Y, heat transfer is only due to conduction. It is found that a transition of different modes of stability may occur as Rayleigh number changes; this fact gives rise to a discontinuity in the variation of critical yield number.

Originality/value

Besides the new numerical method based on the finite element and using a non-uniform unstructured grid for analyzing natural convection of viscoplastic materials with complex boundary conditions, the originality of the present work concerns the treatment of the yield stress fluids under the influence of complex boundary conditions.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 April 1992

S. BRANDON and J.J. DERBY

A finite element method for the analysis of combined radiative and conductive heat transport in a finite axisymmetric configuration is presented. The appropriate…

Abstract

A finite element method for the analysis of combined radiative and conductive heat transport in a finite axisymmetric configuration is presented. The appropriate integro‐differential governing equations for a grey and non‐scattering medium with grey and diffuse walls are developed and solved for several model problems. We consider axisymmetric, cylindrical geometries with top and bottom boundaries of arbitrary convex shape. The method is accurate for media of any optical thickness and is capable of handling a wide array of axisymmetric geometries and boundary conditions. Several techniques are presented to reduce computational overhead, such as employing a Swartz‐Wendroff approximation and cut‐off criteria for evaluating radiation integrals. The method is successfully tested against several cases from the literature and is applied to some additional example problems to demonstrate its versatility. Solution of a free‐boundary, combined‐mode heat transfer problem representing the solidification of a semitransparent material, the Bridgman growth of an yttrium aluminium garnet (YAG) crystal, demonstrates the utility of this method for analysis of a complex materials processing system. The method is suitable for application to other research areas, such as the study of glass processing and the design of combustion furnace systems.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 2 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Open Access
Article
Publication date: 13 September 2019

Juana Du and Rong Wang

The purpose of this paper is to examine innovative practices and emphasize the mechanism of knowledge transfer across knowledge boundaries. By comparing and discussing the…

2762

Abstract

Purpose

The purpose of this paper is to examine innovative practices and emphasize the mechanism of knowledge transfer across knowledge boundaries. By comparing and discussing the emerging boundary issues in knowledge transfer among small- and medium-sized enterprises (SMEs) registered in the incubation centers in China, this paper identified the main knowledge transfer approach and several contextual and organizational factors impacting knowledge transfer.

Design/methodology/approach

The authors conduct 39 semi-structured in-depth interviews with employees working within business incubation centers in China. The study uses thematic analysis for data analysis.

Findings

Our results contribute to the literature of knowledge transfer and in particular to our understanding of boundary conditions and knowledge transfer approaches in emerging economies. The results also highlight several contextual and organizational factors which impact knowledge transformation across the pragmatic boundary in the context of China.

Practical implications

First, organizations need to establish an effective process with tools to accommodate novelty; second, organizations should be aware of the impact of entrepreneurial orientation on innovative performance; and third, it will help organizations if they adopt and integrate information-rich media in managing innovative practices.

Originality/value

This research highlights the impact of contextual and organizational factors of SMEs on knowledge transfer in emerging markets and chooses incubation centers as study subjects, which is an organizational context that has not been thoroughly studied due to its unique nature and emerging complexity.

Details

New England Journal of Entrepreneurship, vol. 22 no. 1
Type: Research Article
ISSN: 2574-8904

Keywords

Article
Publication date: 9 August 2022

Chunyun Zhang, Jie Mei, Yushuai Bai, Miao Cui, Haifeng Peng and X. W. Gao

The purpose of this study is to simultaneously determine the constitutive parameters and boundary conditions by solving inverse mechanical problems of power hardening…

Abstract

Purpose

The purpose of this study is to simultaneously determine the constitutive parameters and boundary conditions by solving inverse mechanical problems of power hardening elastoplastic materials in three-dimensional geometries.

Design/methodology/approach

The power hardening elastoplastic problem is solved by the complex variable finite element method in software ABAQUS, based on a three-dimensional complex stress element using user-defined element subroutine. The complex-variable-differentiation method is introduced and used to accurately calculate the sensitivity coefficients in the multiple parameters identification method, and the Levenberg–Marquardt algorithm is applied to carry out the inversion.

Findings

Numerical results indicate that the complex variable finite element method has good performance for solving elastoplastic problems of three-dimensional geometries. The inversion method is effective and accurate for simultaneously identifying multi-parameters of power hardening elastoplastic problems in three-dimensional geometries, which could be employed for solving inverse elastoplastic problems in engineering applications.

Originality/value

The constitutive parameters and boundary conditions are simultaneously identified for power hardening elastoplastic problems in three-dimensional geometries, which is much challenging in practical applications. The numerical results show that the inversion method has high accuracy, good stability, and fast convergence speed.

Article
Publication date: 2 September 2014

Yanzhong Wang and Bin Wei

The purpose of this study is to investigate wet multi-disc brake temperature field and optimal oil supply under continuous braking condition. The oil supply of wet multi-disc…

Abstract

Purpose

The purpose of this study is to investigate wet multi-disc brake temperature field and optimal oil supply under continuous braking condition. The oil supply of wet multi-disc brake has a direct impact on the drivability and fuel economy for tracked vehicles. Too small flow will result in the higher temperature and failure of brake while excessive one will lead to slow engagement increasing disengaged torque and the transmission efficiency could decline notably. The optimal oil supply and brake temperature field were obtained in this research.

Design/methodology/approach

This article investigated on the heat dissipation capability and optimal oil supply of the brake by the means of CFX model. The working condition was continuous braking and the lubricating and cooling factors were included in the model.

Findings

That the complex trends with increased oil flow is inconsistent with the traditional formula in which the effects of grooves were neglected. The fitting curve of optimal oil supply can predict various needed oil flow in various rotating speed and it provides a theoretical guidance for oil supply design.

Originality/value

Traditional empirical formula of heat transfer coefficient and Reynolds equation solved by different methods could be difficult to deal with the complex boundary conditions of wet multi-disc brake. CFX model can solve the problem of complex boundary condition. The optimal oil supply curve can provide a theoretical guidance for oil supply design.

Details

Industrial Lubrication and Tribology, vol. 66 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 12 February 2024

Azmeera Sudheer Kumar, Subodh Kumar, Prashant Kumar Choudhary, Ankit Gupta and Ashish Narayan

The purpose is to explore the free vibration behaviour of elastic foundation-supported porous functionally graded nanoplates using the Rayleigh-Ritz approach. The goal of this…

82

Abstract

Purpose

The purpose is to explore the free vibration behaviour of elastic foundation-supported porous functionally graded nanoplates using the Rayleigh-Ritz approach. The goal of this study is to gain a better knowledge of the dynamic response of nanoscale structures made of functionally graded materials and porous features. The Rayleigh-Ritz approach is used in this study to generate realistic mathematical models that take elastic foundation support into account. This research can contribute to the design and optimization of advanced nanomaterials with potential applications in engineering and technology by providing insights into the influence of material composition, porosity and foundation support on the vibrational properties of nanoplates.

Design/methodology/approach

A systematic methodology is proposed to evaluate the free vibration characteristics of elastic foundation-supported porous functionally graded nanoplates using the Rayleigh-Ritz approach. The study began by developing the mathematical model, adding material properties and establishing governing equations using the Rayleigh-Ritz approach. Numerical approaches to solve the problem are used, using finite element methods. The results are compared to current solutions or experimental data to validate the process. The results are also analysed, keeping the influence of factors on vibration characteristics in mind. The findings are summarized and avenues for future research are suggested, ensuring a robust investigation within the constraints.

Findings

The Rayleigh-Ritz technique is used to investigate the free vibration properties of elastic foundation-supported porous functionally graded nanoplates. The findings show that differences in material composition, porosity and foundation support have a significant impact on the vibrational behaviour of nanoplates. The Rayleigh-Ritz approach is good at modelling and predicting these properties. Furthermore, the study emphasizes the possibility of customizing nanoplate qualities to optimize certain vibrational responses, providing useful insights for engineering applications. These findings expand understanding of dynamic behaviours in nanoscale structures, making it easier to build innovative materials with specific features for a wide range of industrial applications.

Originality/value

The novel aspect of this research is the incorporation of elastic foundation support, porous structures and functionally graded materials into the setting of nanoplate free vibrations, utilizing the Rayleigh-Ritz technique. Few research have looked into this complex combo. By tackling complicated interactions, the research pushes boundaries, providing a unique insight into the dynamic behaviour of nanoscale objects. This novel approach allows for a better understanding of the interconnected effects of material composition, porosity and foundation support on free vibrations, paving the way for the development of tailored nanomaterials with specific vibrational properties for advanced engineering and technology applications.

Details

International Journal of Structural Integrity, vol. 15 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 May 1999

Bozidar Sarler and Jure Mencinger

The axisymmetric steady‐state convective‐diffusive thermal field problem associated with direct‐chill, semi‐continuously cast billets has been solved using the dual reciprocity…

Abstract

The axisymmetric steady‐state convective‐diffusive thermal field problem associated with direct‐chill, semi‐continuously cast billets has been solved using the dual reciprocity boundary element method. The solution is based on a formulation which incorporates the one‐phase physical model, Laplace equation fundamental solution weighting, and scaled augmented thin plate splines for transforming the domain integrals into a finite series of boundary integrals. Realistic non‐linear boundary conditions and temperature variation of all material properties are included. The solution is verified by comparison with the results of the classical finite volume method. Results for a 0.500[m] diameter Al 4.5 per cent Cu alloy billet at typical casting conditions are given.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 9 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 27 April 2022

Deborah M. McPhee and Francine K. Schlosser

The authors contribute to scholarship on motivation for late-career transition, by examining how older executives drew on individual ambidexterity (IA) in the stigmatized…

Abstract

Purpose

The authors contribute to scholarship on motivation for late-career transition, by examining how older executives drew on individual ambidexterity (IA) in the stigmatized, Canadian-licensed recreational cannabis industry.

Design/methodology/approach

The methodology utilizes a qualitative method, utilizing semi-structured interviews with 15 late-career executives. Inductive examination of data uncovered subthemes related to motivations for late-career transition, exploring and exploiting competencies, and known and unknown boundary conditions.

Findings

Motivations explained the impetus to join, while ambidexterity allowed executives to employ explorative and exploitive competencies to weather boundary conditions. Late-career transitioning to a stigmatized emerging industry presents an unprecedented mode of bridging employment for older workers.

Research limitations/implications

This small exploratory study of a nascent industry is limited in its generalization across different contexts but relevant to others in cannabis and other emerging industries. Increased focus on Human resources management (HRM) related research on late-career transition due to limited studies and IA.

Practical implications

Cannabis can be a risky employment venture for older workers that may affect future job prospects due to stigmatized views or present devastating financial risk. Older workers with knowledge, experience and skill remain relevant utilizing IA and their ability to manage difficult boundary conditions. Older experienced workers can bridge novel new opportunities before retiring.

Originality/value

The authors incorporated IA, expanding on literature related to boundary conditions in the late-career transition of executives into stigmatized recreational Cannabis. The authors introduce a new mode of bridge employment for late-career workers.

Details

Career Development International, vol. 27 no. 3
Type: Research Article
ISSN: 1362-0436

Keywords

Article
Publication date: 12 April 2023

Shutao Li, Xin Bao, Jingbo Liu, Fei Wang and Dong Wang

When explicit integral analysis is performed on a numerical model with viscoelastic artificial boundary elements, an instability phenomenon is likely to occur in the boundary

Abstract

Purpose

When explicit integral analysis is performed on a numerical model with viscoelastic artificial boundary elements, an instability phenomenon is likely to occur in the boundary area, reducing the computational efficiency of the numerical calculation and limiting the use of viscoelastic artificial boundary elements in the explicit dynamic analysis of large-scale engineering sites. The main purpose of this study is to improve the stability condition of viscoelastic artificial boundary elements.

Design/methodology/approach

A stability analysis method based on local subsystems was adopted to analyze and improve the stability conditions of three-dimensional (3D) viscoelastic artificial boundary elements. Typical boundary subsystems that can represent the localized characteristics of the overall model were established, and their analytical stability conditions were derived with an analysis based on the spectral radius of the transfer matrix. Then, after analyzing the influence of each physical parameter on the analytical-stability conditions, a method for improving the stability condition of the explicit algorithm by increasing the mass density of the artificial boundary elements was proposed.

Findings

Numerical wave propagation simulations in uniform and layered half-space models show that, on the premise of ensuring the accuracy of the viscoelastic artificial boundary, the proposed method can effectively improve the numerical stability and the efficiency of the explicit dynamic calculations for the overall system.

Originality/value

The stability improvement method proposed in this study are significant for improving the applicability of viscoelastic artificial boundary elements in explicit dynamic calculations and the calculation efficiency of wave analysis at large-scale engineering sites.

Details

Engineering Computations, vol. 40 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

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