bluuebunny/crossref_metadata_2025 huggingface dataset:
Decision support tool for blank selection in workshop machining processes
Authors: Quintana G. , Ciurana J. , G‐Romeu M. L.
Published: March 2008

Purpose

Nowadays there is a trend in industry to optimize processes through computerization. In the field of machining, computer assistance is available to design and describe the product, analyze and simulate its behaviour, describe the manufacturing conditions and generate the corresponding orders. These are the CAD, CAM and computer aided process planning systems. However, there are no computer applications for machining processes that offer assistance to determine the characteristics of the blank. This task is usually done by workshop operators, numerical control programmers, process planners or other professionals whose knowledge and, especially, experience allow them to carry it out. This paper aims to present a computer application that provides assistance to select the characteristics of the blanks used in machining processes.

Design/methodology/approach

The methodology applied consists of studying the methods experts use to choose blanks, analyzing the variety of parts that are currently machined in the workshops, designing the application and then implementing and validating it.

Findings

The system developed calculates the characteristics of the blank and optimizes the decision according to the experience, knowledge and methods of the experts. This application can carry out calculations for any of the parts that are usually manufactured in a workshop. The solutions that the programme offers can be developed using current‐cutting techniques or the profiles that suppliers sell in the market. The paper includes a case study to demonstrate how the tool is used. Implementation of this computer application brings the present industry closer to production optimization and computerization of the processes (computer integrated manufacturing).

Originality/value

This is the first time the knowledge and the reasoning methods of experts have been analyzed and implemented in a computer tool that gives assistance to determine the characteristics of the blank.
The comparative body model in material and geometric nonlinear analysis of space R/C frames
Authors: Trogrlic Boris , Mihanovic Ante
Published: March 2008

Purpose

This paper aims to present a new numerical model for the stability and load‐bearing capacity computation of space reinforced‐concrete (R/C) frame structures. Both material and geometric nonlinearities are taken into account. The R/C cross‐sections are assumed to undergo limited distortion under torsional action.

Design/methodology/approach

A simple, global discretization using beam‐column finite elements is preferred to a full, global discretization using 3D elements. This is more acceptable from a practical point of view. The composite cross‐section is discretized using 2D elements to apply the fiber decomposition procedure to solve the material and geometrical nonlinear behavior of the cross‐section under biaxial moments and axial forces. A local discretization of each beam element based on the comparative body model (i.e. a prismatic body discretized using brick elements, element by element, during the incremental‐iterative procedure) allows determining the torsional constant of the cross‐section under limited warping. The classical global iterative‐incremental procedure is then used to solve the resulting material and geometric nonlinear problem.

Findings

It has been noticed that, in case of a limited distortion of the cross‐section, the torsional constant of homogeneous (linear elastic) materials is greater than the one obtained from the Saint‐Venant theory. However, due to low‐tensile strength of concrete materials, the torsional constant decreases significantly after an early loading phase, primarily due to the lack of reinforcing flanges.

Research limitations/implications

The current study does not cover the torsion analysis of R/C cross‐section with stirrups. Besides, the bond‐slip effect between concrete and steel reinforcement is not taken into account, nor is the local buckling of the beam flanges and rebar.

Practical implications

This new numerical model has been implemented in a computer program for effectively computing the nonlinear stability and load bearing capacity of space R/C frames.

Originality/value

The authors believe that the comparative body model should bring a new approach to the solution of torsion problems with limited distortion of cross‐sections in material and geometric nonlinear analysis of space R/C frames.
Consumer ethnocentrism in the German market
Authors: Evanschitzky Heiner , v. Wangenheim Florian , Woisetschläger David , Blut Markus
Published: March 2008

Purpose

International marketing researchers have long been concerned with determining whether consumers are predisposed towards a preference for domestic products, as opposed to foreign products. The purpose of this paper is to assess such a domestic‐country bias (DCB) in the German market.

Design/methodology/approach

This study empirically investigates DCB across six countries and 14 product categories in the Germany market. By so doing, it replicates an earlier study conducted in the UK. Ordered logit analysis was employed as well as multidimensional unfolding to present results.

Findings

As in the study conducted in the UK, there is in general a strong DCB in the German market. However, it differs largely across the 14 product categories. Results indicate that consumer preference rankings can best be explained by a combination of demographic variables and country‐of‐origin effects.

Practical implications

Results indicate that domestic firms in Germany can well rely on a safeguarding effect when marketing their products. At the same time, managers from foreign countries cannot rely on consumer ethnocentrism as a reliable indicator of the inclination of consumers to downgrade their products.

Originality/value

This study confirms some findings from the UK. However, results from Germany indicate that at least economic competitiveness of the country‐of‐origin plays a role in determining respondents' judgments. This study underlines the value of replication studies in cross‐cultural settings in particular.
Consumers' need for uniqueness: short‐form scale development and cross‐cultural validation
Authors: Ruvio Ayalla , Shoham Aviv , Makovec Brenčič Maja
Published: March 2008

Purpose

The purpose of this paper is to develop and validate cross‐culturally a short‐form, consumers' need for uniqueness (CNFU) scale. The length of the original scale (31 items) might have hindered its diffusion in research when questionnaire length and respondent fatigue are major considerations.

Design/methodology/approach

The paper uses survey‐based data from Israel, Slovenia, and the Palestinian Authority and uses a combination of statistical techniques, such as EFA, CFA, and structural equation modeling.

Findings

In general, support was found for the cross‐cultural reliability and validity of the new, short‐form CNFU scale.

Research limitations/implications

Future research can use the short‐form scale with additional confidence in its cross‐cultural reliability and validity.

Practical implications

First, since CNFU appears not to be culturally bound, marketers can identify cross‐country segments of high‐CNFU individuals and use standardized marketing campaigns to reach them. Second, marketers of unique products can use the antecedents identified in this study to develop and encourage CNFU. Third, the findings can be used to design advertising campaigns such as by emphasizing the social context of consumption of high‐uniqueness products.

Originality/value

An original and first presentation of a cross‐cultural validation of a parsimonious CNFU scale.
The impact of national stereotypes on the country of origin effect
Authors: Chattalas Michael , Kramer Thomas , Takada Hirokazu
Published: March 2008

Purpose

The purpose of this paper is to advances a conceptual framework in which the impact of national stereotype dimensions on country of origin (COO) effects is explicitly modeled and decomposed.

Design/methodology/approach

This paper proposes that the perceived warmth and perceived competence dimensions of national stereotypes underlie COO effects. The conceptual framework posits research propositions on the potential interactions of these dimensions with product type (such as hedonic versus utilitarian and high‐ versus low‐contact services), while the effects of consumer characteristics (such as cultural orientation, expertise, involvement, and ethnocentrism) are explored.

Findings

The Stereotype Content Model is a useful tool in exploring the relationship between national stereotypes and COO‐based evaluations as it represents a major theoretical advance in the systematic study of stereotype contents.

Practical implications

The advanced conceptual framework holds significant practical implications for the international marketing strategies of corporations as well as nations.

Originality/value

This paper proposes an original conceptualization and testable research propositions regarding the relationship between national stereotype contents and COO‐based consumer evaluations of products.
Effect of brand extension strategies on brand image
Authors: Martinez Eva , Polo Yolanda , de Chernatony Leslie
Published: March 2008

Purpose

The purpose of this paper is to propose and test a model that shows how extending a brand affects the overall brand image. The relations between the relevant variables in brand extension strategies in the UK and Spanish markets are analysed to determine if the brand extension strategies have the same effect on brand image.

Design/methodology/approach

An empirical study was conducted in the UK and Spain using structural equation analysis. Two pre‐tests were conducted to select the brands and the extensions.

Findings

Results show that the brand extension strategy dilutes the brand image in both markets. It is found that brand image before extension and fit has positive effects on brand image after extension. The concurrence between the models studied in the two markets suggests that UK and Spanish consumers respond similarly to brand extensions.

Research limitations/implications

The study was only conducted in two countries. Researchers are encouraged to test the model in more countries.

Practical implications

Results suggest that a firm which has a good brand image before the extension will be less at risk when it launches a new product onto the market with the same brand name. Its best market will be those consumers who already know the brand's products and who at the same time perceive a better image of it. The firm should not forget that the closer the extended product is to its core market, the more positive will be its acceptance by consumers, which will translate into a better image evaluation.

Originality/value

The study analyses how extending a brand may affect the parent brand image in global brand.
An organizational learning model for vocational education in the context of TQM culture
Authors: Lam M.Y. , Poon Gary K.K. , Chin K.S.
Published: March 2008

Purpose

The purpose of this paper is to try to establish a relationship between organizational learning capability (OLC) and TQM culture (TC) based on a case study of a leading vocational education institution of Hong Kong, and to develop an organizational learning transformation model for vocational education in the context of TQM culture.

Design/methodology/approach

The linkage between OLC and TC constructs is established and confirmed statistically by a structured questionnaire survey. Key TC constructs are then identified and prioritized using analytic hierarchy process (AHP) based interview, focus group, and ethnographic study to formulate an empirical TQM culture based OL transformation model for vocational education. Finally, the validity and effectiveness of the model is verified through an actual implementation case.

Findings

Strong positive correlation is found between the OLC and TC constructs, while shared vision, long‐term focus, and teacher involvement are identified to be the key TC constructs that can have significant impact on OLC in vocational education. It also confirms that rules orientation prohibits the creation of TQM culture, while innovative leadership does nurture its formation. An empirical TQM culture based OL transformation model for vocational education is formulated and subsequently tested through an implementation case. The result confirms that the model can effectively facilitate a transition of a traditional vocational education institution towards a learning organization for organizational excellence.

Originality/value

Although the evolutionary development and theory supports for TQM and Organizational Learning (OL) are distinct, they appear to have more in common than they have in distinctiveness. However, there is little synergy developed between these two fields so far both in academia and industry. The paper establishes a theoretically informed and statistically confirmed organizational learning transformation model for vocational education in the context of TQM culture.
Main quality programs characteristics in large size Brazilian companies
Authors: Helena Boarin Pinto Silvia , Monteiro de Carvalho Marly , Lee Ho Linda
Published: March 2008

Purpose

The purpose of this paper is to identify the relationships as to complementarities and redundancies of the main quality programs in large Brazilian companies by a comparative and critical analysis of their implementation in those companies.

Design/methodology/approach

In the paper the survey methodology was utilized. The data collection was done from “Ranking Valor 1000” list, which comprises the 1,000 largest Brazilian companies; the assumption was that in these companies the embryos of the emerging models in quality management were to be found. The data collected from questionnaires were analyzed through statistical methods.

Findings

The findings showed that the large organizations in Brazil have been investing in quality programs.

Research limitations/implications

This paper presents the limitations which are inherent to the research method applied, that is, the results should not be generalized because the collected data are not originated in a probabilistic sample.

Practical implications

The paper shows that the companies where the Six Sigma program was implemented are those with the strongest tradition in the market; the companies that most invested in quality by adopting these programs were successful according to the quality performance indicators as well as concerning the return on investment; and the main causes of failure in the quality programs analyzed in this study were shortage of financial resources for the proper implementation of the programs and the fragile support given by the company management.

Originality/value

This paper may prove to be significantly helpful to a better and deeper understanding of the factors influencing the quality programs adopted by Brazilian companies.
The value of quality improvements
Authors: Setijono Djoko , Dahlgaard Jens J.
Published: March 2008

Purpose

The purpose of the paper is to present a proactive quality costs measurement methodology, which describes the value of quality improvements and the implication of this value on customers' perception regarding the value of the product.

Design/methodology/approach

By describing the perceived customer value in a dynamic term, it becomes possible to derive an analytical model that recognizes the implication of a company's efforts to improve design quality and conformance quality on product value as perceived by the customers. Quality costs as a performance indicator of improved design quality and conformance quality (as the results of prevention and appraisal activities) can be expressed in terms of value (i.e. a trade‐off between benefits and sacrifices), where the benefits of the improvement include higher product quality and reduction of failure costs. The sacrifices include the costs to perform improvement activities (i.e. prevention and appraisal costs). Expressing quality costs in this way thus establishes a link between a producer's efforts to improve quality and the way customers perceive the value of the product. The developed methodology of proactive quality cost measurement has been applied for collecting, measuring, and reporting quality costs in a Swedish wood‐flooring manufacturing company.

Findings

Transforming quality cost measurements into value provides a better explanation regarding the effect of prevention and appraisal activities on the quality improvement indicators. Thus, the value of quality improvements is a measure of return on quality improvements (ROQI), which indicates whether the quality improvement efforts gave higher, fair, or lower return.

Originality/value

This paper develops and discusses a model of customer value by accommodating its relative nature, and presents a proactive way of measuring quality costs (i.e. value‐oriented and customer‐oriented).
The impact of the setting of air‐jet looms on the fabric quality: an investigation
Authors: Brun Alessandro , Corti Donatella , Pozzetti Alessandro
Published: March 2008

Purpose

The purpose of the paper is to provide a methodology aimed at improving the setting up of air‐jet looms by clarifying the function which links different important variables involved in the setting procedure and by proposing a method to measure the quality of fabrics depending on the factor values.

Design/methodology/approach

The proposed procedure is based on the use of a load sensor: the tension profile received from it is used to analyse the weft behaviour and, sometimes, to predict any quality problems. Because of the high number of variables influencing the set up, the factorial experiments have been used to develop the setting procedure. Numerical results have been analyzed by means of a regression analysis and an ANOVA analysis.

Findings

Relationships among different variables and their influence on the quality of the fabric have been derived thanks to the use of a load sensor.

Research limitations/implications

So far, the proposed procedure has been developed for air‐jet looms and for a limited set of fabrics, but it could be adapted in other situations as well.

Practical implications

Use of the proposed procedure allows practitioners to reduce cost and time of the setting up of air jet looms. High productivity of air jet looms could be thus better exploited also for producing small batches of products.

Originality/value

The combination of the load sensor and the statistical analysis allowed the development of a systematic setting procedure for air‐jet looms.
An overview on reliability, availability, maintainability and supportability (RAMS) engineering
Authors: Saraswat S. , Yadava G.S.
Published: March 2008

Purpose

The purpose of this paper is to provide an overview of RAMS engineering in industry and research.

Design/methodology/approach

A range of research articles (1988‐2005) covering RAMS engineering is discussed to provide a practical and theoretical overview of RAMS engineering in industry and research.

Findings

The paper provides information about the current scenario and also about the past scenario of RAMS engineering in research and industry.Research limitations/implications– This paper reviews much of the literature on RAMS engineering. The literature is collected from major journals and conference proceedings, the period covered is from 1988 to 2005. The authors have tried to make it reasonably comprehensive, but those papers which are not included were either inadvertently overlooked or considered peripheral to this survey. In the present work the authors have only considered those articles which have included two or more aspects of RAMS.Practical implications– The paper is a very useful source of information for researchers working in the area of RAMS engineering.Originality/value– This paper offers help to researchers in understanding the current and past status of RAMS.
Vision by design: a reflexive approach to enterprise regeneration
Authors: Finkelstein Sydney , Harvey Charles , Lawton Thomas
Published: March 2008

Purpose

This paper aims to introduce a strategic visioning method called vision by design and to use the example of Harley‐Davidson's corporate regeneration to illustrate how the method works in practice. This approach conceives visioning as a practical tool of management whose power stems from the facilitation of strategic conversations among stakeholders and the reflexive engagement of business leaders in past‐present‐future thinking.

Design/methodology/approach

The paper presents a four‐dimensional visioning model that facilitates exploration of both the internal and external contexts of the business. The advantage of the approach lies in breaking down vision into its component parts, lending simplicity and structure to the visioning process. The study employs a case study of the turnaround of Harley‐Davidson to illustrate this method.

Findings

The paper finds that, in undertaking corporate regeneration, Harley‐Davidson's senior management recognized the need for a vision that was comprehensive, inclusive and dynamic, but also realistic and grounded in the history and present circumstances of the business. The visioning process at the company was transformational because it ignited a strategic conversation that went beyond the boardroom to include employees, customers, partners and financiers.

Originality/value

The vision by design method adds value by simplifying the visioning process and focusing on a series of transitions, whereby the emerging vision is rooted squarely in business realities. As the picture of a regenerated enterprise is built up, both internal and external contexts are scrutinized, ensuring that the future vision is consistent and complete, attractive externally and deliverable internally.
Driving renewal: the entrepreneur‐manager
Authors: Chakravarthy Bala , Lorange Peter
Published: March 2008

Purpose

Strategic renewal requires both a top‐down and bottom‐up effort. Top management sets the broad vision for the firm and specifies the scope and pace of renewal. However, it is the firm's entrepreneur‐managers who shape its renewal strategies and take responsibility for their implementation. This paper aims to profile the skills, personal traits and experiences of successful entrepreneur‐managers.

Design/methodology/approach

The paper uses field research.

Findings

The paper finds that entrepreneur‐managers are in part corporate entrepreneurs. They are outward‐focused, cognizant of changes in their business environment and the new opportunities that these may bring. They are willing to experiment with new business models and to explore new capabilities. But they are also operating managers interested in scaling up an entrepreneurial idea and in delivering results. They have a few special personality traits. They are not risk averse and are action oriented. They are also supremely self‐confident. These traits allow entrepreneur‐managers to take risks, persist despite failures and learn from their mistakes. However, more than special traits, it is experience that grooms entrepreneur‐managers in a firm. Entrepreneur‐managers are typically not new comers to the organization. Their long tenure helps with networking inside the firm. They also have an established track record of performing well. That buys them the freedom to operate outside the usual confines of the organization and enjoy the trust that is needed to take risks on behalf of the firm.

Research limitations/implications

Like in any field‐based study, the sample size is a limitation. However, for the modest goal that this paper has set for itself, i.e. profiling the entrepreneur‐manager, this is not a severe limitation.

Practical implications

The paper provides a profile for identifying and nurturing entrepreneur‐managers. As it argues, they are the drivers of strategic renewal within the firm.

Originality/value

Prior empirical and theoretical research on intrapreneurship has focused more on creating distinct new corporate ventures. This article suggests that the real power of intrapreneurship is to help connect the future of the firm with its current core businesses. Intrapreneurship is about leverage and build, more so than transform, to use the three types of renewal strategies that are offered in this article.
The DNA of Innovation
Authors: Dobni C. Brooke
Published: March 2008

Purpose

A survey by Gary Hamel's company (Strategos) identified that over 80 percent of senior managers agreed that innovation creates a strong source of competitive advantage, and 90 percent indicated that innovation is highly valued. Yet these same companies rated themselves poorly at innovation. This paper sets out to consider behaviors and traits that will help organizations to successfully innovate.

Design/methodology/approach

Recent articles have attempted to use the concept of scientific DNA as a metaphor to describe characteristics of an organization. Many of these are descriptive and refer to basic core activities that managers need to concern themselves with. This article presents an analogy of DNA for the business perspective. There are certain behaviors and traits – call them innovation genes – that are foundational to innovation. It is believed that the sequence presented is this paper represents the basic building blocks for organizational innovation.

Findings

The paper finds that the innovation DNA sequence includes employee centric traits of knowledge management, cluster management, value management, and alignment. The context shaping innovation includes employee constituency and empowerment. The outcomes include strategic architecture to support innovation, innovation mapping of strategic initiatives, and value creation. There are competitive and positioning advantages of innovation DNA that promote a sustainable competitive advantage.

Originality/value

Embedding innovation DNA into the organization's fabric elevates organizations to being innovative in everything they do ‐ from knowledge management to value creation, and execution. Its application is universal as it elevates the least common denominator respecting how employees think and act; behaviors which lend life to innovation. As a result, the innovation imperative will only be as good as the organization's lowest common denominator in this respect.
Predicting changes in industry structure
Authors: Jackson Stuart E.
Published: March 2008

Purpose

Previous Reaching for value columns, have looked at companies and industries in historical terms. (How did smart companies use strategic market positioning (SMP) to make acquisitions and other investments? How did less smart companies pick the wrong growth path?) This column aims to consider how the basis of competition in an industry can change over time, with big implications for many of those operating in the industry today. A challenge for business strategists is to know when the time is right to launch new business models that go against established business practices. Too late and they risk ceding first‐mover advantage to competitors; too early and they risk launching businesses that fail to yield expected operating benefits and financial returns. This paper seeks to usesthe example of the healthcare industry to examine how changing operating models and market forces are likely to influence the future competitive landscape for US healthcare providers.

Design/methodology/approach

In this paper, different sectors of the US healthcare industry are considered and what has caused some sectors to be dominated by national or global‐scale competitors while others continue to be served by thousands of local‐scale providers are examined. To illustrate the points the recent emergence of retail clinics, such as RediClinic, owned by national pharmacy companies and attempts by hospital organizations such as HCA and Mayo to build national‐scale businesses are considered.

Findings

The paper finds that just because an industry sector has been operating one way for many years does not mean that the basis of competition can never change. Companies that can identify when new technology or other factors have made the conditions right for a newer, more efficient way of doing business can unlock value and leapfrog competitors by launching new product or service offerings and building the right capabilities and scale for the new environment.

Originality/value

By looking in detail at current and future benefits of scale in the healthcare industry, the paper provides valuable insights into how to understand and predict when major discontinuities in the structure of an industry sector are likely to.
State of the art of numerical modeling for induction processes
Authors: Lavers J.D.
Published: March 2008

Purpose

To provide a selective bibliography for researchers and graduate students who have an interest in induction processes applied to the electromagnetic processing of materials.

Design/methodology/approach

The objective is to provide references that identify seminal, early work, and references that represent the current state of the art. References are listed in categories that cover the broad range of induction modeling and application issues.

Findings

A brief overview of the key areas in induction processing of materials is provided, but greater emphasis and space is devoted to the references provided.

Research limitations/implications

The middle years of each topic area are not covered.

Practical implications

A very comprehensive coverage of material is provided to those with an interest in induction processing of materials.

Originality/value

This paper fulfils an identified information/resources need.
Dynamic melting model for small samples in cold crucible
Authors: Bojarevics V. , Pericleous K.
Published: March 2008

Purpose

A small size cold crucible offers possibilities for melting various electrically conducting materials with a minimal wall contact. Such small samples can be used for express contamination analysis, preparing limited amounts of reactive alloys or experimental material analyses. Aims to present a model to follow the melting process.

Design/methodology/approach

The presents a numerical model in which different types of axisymmetric coil configurations are analysed.

Findings

The presented numerical model permits dynamically to follow the melting process, the high‐frequency magnetic field distribution change, the free surface and the melting front evolution, and the associated turbulent fluid dynamics. The partially solidified skin on the contact to the cold crucible walls and bottom is dynamically predicted. The segmented crucible shape is either cylindrical, hemispherical or arbitrary shaped.

Originality/value

The model presented within the paper permits the analysis of melting times, melt shapes, electrical efficiency and particle tracks.
Numerical studies of the melting process in the induction furnace with cold crucible
Authors: Umbrasko A. , Baake E. , Nacke B. , Jakovics A.
Published: March 2008

Purpose

Aims to present recent activities in numerical modeling of cold crucible melting process.

Design/methodology/approach

3D numerical analysis was used for electromagnetic problem and 3D large eddy simulation (LES) method was applied for fluid flow modeling.

Findings

The comparative modeling shows, that higher H/D ratio of the melt is more efficient when total power consumption is considered, but this advantage is held back by higher heat losses through the crucible walls. Also, calculations reveal that lower frequencies, which are energetically less effective, provide better mixing of the melt.

Originality/value

3D electromagnetic model, which allows to take into account non‐symmetrical distribution of Joule heat sources, together with transient LES fluid flow simulation gives the opportunity of accurate prediction of temperature distribution in the melt.
Strategy of coupling to model physical phenomena within molten glass bath heated by direct induction
Authors: Jacoutot Laetitia , Sauvage Emilien , Gagnoud Annie , Fautrelle Yves , Brun Patrice , Lacombe Jacques
Published: March 2008

Purpose

This paper aims to report on a vitrification process based on direct induction that has been developed by the French Atomic Energy Commission (CEA, France). This process is characterized by currents directly induced inside the molten glass and by the cooling of all the crucible walls. In addition, a mechanical stirring device is used to homogenize the molten glass. This paper presents a global modelling of coupled phenomena that take place within the glass bath.

Design/methodology/approach

Electromagnetic, thermal and hydrodynamic phenomena are modelled. The aim of this study is to develop strategy of coupled modelling between these aspects. The thermohydrodynamic calculations are achieved with the Fluent software (distributed by Fluent France) and the electromagnetic aspects are solved by the OPHELIE program based on integral methods (developed in EPM laboratory).

Findings

Two configurations are considered: the first deals with thermal convection in an unstirred bath and the second takes into account the mechanical stirring.

Research limitations/implications

The main limitation is that repartition of the Joule power density within the molten glass is supposed to be not perturbed by the intrusive elements like the thermocouples or the stirrer. This assumption allows us to perform only axisymmetric calculations of induction effect.

Originality/value

This paper present different strategy of coupling the thermohydrodynamic and direct induction phenomena taken place in the molten glass.
Modelling of EM glass convection
Authors: Cepīte D. , Jakovičs A. , Halbedel B. , Krieger U.
Published: March 2008

Purpose

To develop the mathematical model, which allows predicting the temperature and flow distribution of an opaque glass melt with the temperature‐dependent properties in case it is generated by electromagnetic and thermal convection. Analysis has been done for geometry of the model crucible with the immersed rod electrodes. Numerical analysis is used as a tool for finding out the parameters of the system, which allow getting desiderated homogeneity of temperature field by EM action.

Design/methodology/approach

ANSYS CFX software is implemented for coupling of EM, thermal and HD processes in the modelled system. Usability of non‐inductive approximation is shown using a full harmonic analysis in ANSYS.

Findings

External magnetic field can impact the temperature distribution in the whole volume of the melt significantly, it relocates the hottest zones and changes the maximal temperature in the melt. Qualitative agreement between the numerical and experimental results has been obtained. Dependence of the potential difference between the electrodes on the velocity and temperature range has been examined. Impact of different thermal boundary conditions has been analysed.

Research limitations/implications

Effects analysed in the publication occur in each conducting media subjected to the impact of simultaneous electrical and magnetical field. The main limitation is non‐transparency of the melt.

Practical implications

The purpose is to develop a mathematical tool for parameter optimisation of real glass melting furnace.

Originality/value

In the present model temperature dependent properties of the melt have been taken into account, which has been neglected in previous models.
Magneto‐thermal‐motion coupling in transverse flux heating
Authors: Tudorache Tiberiu , Fireteanu Virgiliu
Published: March 2008

Purpose

This paper aims to deal with the 3D finite element analysis of metallic sheets heating in translating motion through the air gap of an inductor of transverse flux type.

Design/methodology/approach

This study presents two finite element based motion coupling techniques used to analyze the transient temperature field of moving metallic sheets heated by induction.

Findings

The numerical results obtained by the two different magneto‐thermal – translating motion coupling techniques proposed in this paper are in good agreement with each other being validated also by experimental measurements.

Practical implications

The proposed numerical techniques can be used for the design and optimization of transverse flux induction heating systems.

Originality/value

An original solution to improve the transversal thermal profile of the metallic sheet based on the magnetic shielding is proposed and analyzed. The numerical results of the thermal field are validated by experimental measurements.
Skin effect in toroidal conductors with circular cross‐section
Authors: Aliferov A. , Lupi S.
Published: March 2008

Purpose

The paper deals with the current density distributions in toroidal conductors of circular cross‐section.

Design/methodology/approach

A review of the analytical solutions existing in the literature only for the case of very thin skin depth is presented.

Findings

Results are given for different aspect ratios of torus. The accuracy of these analytical solutions is verified by comparison with numerical results. Finally, a set of numerical results are given for the same aspect ratios but different penetration depths of the electromagnetic wave in the conducting material.

Originality/value

The paper provides results for different penetration depths of electromagnetic wave in conducting material and different torus aspect ratios.
Numerical modeling of the controlled solidification process
Authors: Nagy Ştefan , Leuca Teodor , Mich‐Vancea Claudiu
Published: March 2008

Purpose

This paper aims to present a numeric modeling of the electromagnetic and thermal phenomena for the non‐ferromagnetic alloys casting equipment that control the solidification structure's formation.

Design/methodology/approach

The paper uses a numerical modeling program for the controlled solidification process modeling to allow visualization of the thermal field variation.

Findings

The probes cast using this method will have a uniform structure, without micro‐fissures. If the solid's part growth of the molten is controlled, we can stop the process that creates solidification centers, thus the material structure will be homogenous. A solution for this matter is given by the control of the solidification structure using forced heating of the liquid part with eddy currents and forced cooling of the solid part. The evolution of the area with eddy currents and the cooled one controls the phase transformation.

Originality/value

The paper presents a procedure to solve the coupled electromagnetic and thermal field problem in the casting systems techniques: solidification with controlled phase variation layer.
Thermal analysis of an eddy‐current heated piece by means of the FEM‐DBCI method
Authors: Aiello G. , Alfonzetti S. , Dilettoso E. , Salerno N.
Published: March 2008

Purpose

This paper aims to propose a hybrid method, called finite element method‐Dirichlet boundary condition iteration (FEM‐DBCI), for the computation of time‐harmonic eddy current problems inside a conductor heated by coils in 3D open‐boundary geometry.

Design/methodology/approach

The method assumes the electrical field as unknown on a mesh of tetrahedral edge elements. The heating power density inside the conductor is then computed and a steady‐state thermal analysis is performed on the same mesh of nodal tetrahedra to calculate the temperature distribution inside the heated piece, taking radiation and convection into account. A numerical example is also provided.

Findings

The method couples a differential equation for the interior problem in terms of the electric fields with an integral equation for the exterior one. The global algebraic system is efficiently solved in an iterative way.

Originality/value

The paper illustrates the computation of time‐harmonic eddy current problems inside a conductor heated by coils.
Shunt active power filter implementation for induction heating applications
Authors: Bojoi R. , Griva G. , Profumo F. , Cesano M. , Natale L.
Published: March 2008

Purpose

This paper aims to present the prototype of a 140 kVA shunt active power filter (APF) for current harmonics and fundamental reactive power compensation of a 200 kW induction heating system.

Design/methodology/approach

Design issues of the power components, of the switching ripple filter and of the digital control are addressed and discussed. The APF control algorithm has been implemented on the 16‐bit, fixed‐point, TMS320LF2407 A DSP controller. The current control is based on proportional‐sinusoidal signal integrators with good performance in current harmonic elimination and power factor compensation.

Findings

The experimental tests, performed in real industrial environment for a 200 kW induction heating plant, show that the performance goals are fulfilled.

Practical implications

The sinusoidal signal integrators (for consistency with the other plural forms of acronyms) of the current controller are implemented in the rotating reference frame aligned with the voltage vector at the point of common connection. This allows the compensation of two harmonics with a single SSI, thus halving the computational effort of the DSP.

Originality/value

In industrial induction heating, the need for harmonic and reactive power compensation lasts a few seconds per minute, making passive solutions not suitable. The presented APF is a valid solution for this application, where only a few tailored implementations are available on the market.
Three‐dimensional eddy current analysis in unbounded domains by a DEM‐BEM formulation
Authors: Alotto Piergiorgio , Gruosso Giambattista , Moro Federico , Repetto Maurizio
Published: March 2008

Purpose

To propose a novel 3D hybrid approach, based on a discrete formulation of Maxwell equations (the cell method – CM), suitable for solving eddy current problems in unbounded domains.

Design/methodology/approach

Field equations for magnetodynamics are expressed directly in algebraic form thanks to the CM. The eddy current problem inside bulk conductors is formulated in terms of discrete modified vector potential, whereas magnetic scalar potential is used in order to model the free space. The CM is coupled to the boundary element method by using a surface boundary operator, which maps the surface magnetic fluxes to the surface magnetic scalar potentials. This leads to a unique set of linear equations to be solved in terms of discrete potentials. The eddy currents in bulk conductors are then obtained from discrete potentials.

Findings

It is shown that formulation of hybrid approaches can be simplified by expressing field equations directly in algebraic form without need of weighted residual techniques. An original strategy, based on Green's formula for the magnetic scalar potential, is proposed in order to couple conducting parts to the exterior domain.

Research limitations/implications

Conducting bodies with multiply connected parts cannot be modelled by the proposed approach, since it is based on the magnetic scalar potential. The resulting global matrix is partially dense and non‐symmetric; therefore, standard iterative solvers such as GMRES have to be used.

Practical implications

The proposed approach can be suitably used for analyzing eddy current problems involving models with high degree of complexity, large air domains and moving parts. These are typical of induction heating processes.

Originality/value

This paper proposes a new 3D hybrid approach, based on a discrete formulation of Maxwell equations. A novel coupling strategy relying on integral electromagnetic variables, i.e. magnetic fluxes and magnetic scalar potentials, is devised in order to solve uniquely for eddy currents inside conducting bodies.
Electromagnetic and thermal analysis of the induction heating of aluminum billets rotating in DC magnetic field
Authors: Araneo R. , Dughiero F. , Fabbri M. , Forzan M. , Geri A. , Morandi A. , Lupi S. , Ribani P.L. , Veca G.
Published: March 2008

Purpose

The paper aims to deal with the induction heating of metal billets rotating in a DC magnetic field.

Design/methodology/approach

The induced power distributions are analysed and the main heating parameters are estimated with reference to an infinitely long Al billet 200 mm diameter. The paper refers to the activity developed in the frame of a National Italian Project carried out by research groups of the Universities of Bologna, Padua and Roma “La Sapienza.”

Findings

The main process parameters have been evaluated for the heating up to 500°C of an Al billet 200 mm diameter.

Practical implications

This innovative technology appears to be very promising for improving the efficiency of the through heating of high‐conductivity metals (e.g. copper, aluminum) before hot working, by using superconducting magnets.

Originality/value

The paper analyses the induction heating of a infinitely long billet rotating in a uniform DC magnetic field.
DC induction heating of aluminum billets using superconducting magnets
Authors: Fabbri Massimo , Morandi Antonio , Luigi Ribani Pier
Published: March 2008

Purpose

To analyse the heating process of an aluminum billet rotating in a static magnetic field produced by superconducting coils.

Design/methodology/approach

The idea is to force the billet to rotate in a static magnetic field produced by a DC superconducting magnet. Since, a static superconducting magnet has no losses, the efficiency of the system is the efficiency of the motor used. In order to evaluate the temperature distribution arising from the field profile produced by a given coil configuration, a numerical model, based on an equivalent electric network with temperature‐dependent parameters, is used.

Findings

The main heating parameters, i.e. heating time, total power injected and temperature difference, are evaluated for different values of angular velocity and magnetic field. The field profile suitable to meet the specifics of an industrial heating process in terms of temperature homogeneity and heating time is determined. Starting form this profile the layout of the magnet is arrived at and some considerations on the operating condition of the superconducting windings are reported.

Research limitations/implications

The mechanical stress in the billet due to weight, centrifugal effects, applied torque and resonance is examined by taking into account the weakening of the material properties with the increase of temperature and the practical limits of the heating process are evaluated.

Practical implications

DC induction heating of aluminum billet using superconducting magnets can be done fulfilling the specifics of the industrial processes.

Originality/value

A high‐efficiency induction heater for aluminum billets using superconducting coils in a novel scheme is investigated.