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Article
Publication date: 19 September 2008

G. Comini, C. Nonino and S. Savino

The purpose of this paper is to examine the modeling of simultaneous heat and mass transfer under dehumidifying conditions. Moist air cooling in tube‐fin exchangers is…

Abstract

Purpose

The purpose of this paper is to examine the modeling of simultaneous heat and mass transfer under dehumidifying conditions. Moist air cooling in tube‐fin exchangers is investigated using a finite element technique.

Design/methodology/approach

The model requires the solution of a conjugate problem, since interface temperatures must be calculated at the same time as temperature distributions in adjacent fluid and solid regions. The energy equation is solved in the whole domain, including the solid region, and the latent heat flux on the surfaces where condensation takes place is taken into account by means of an additional internal boundary condition.

Findings

Thermal performances for different Reynolds numbers of a typical two‐row tube‐fin exchanger are numerically analysed, for both in‐line and staggered arrangements of tubes. The results justify the great importance that the ratio between latent and overall rates of heat transfer has in the design of compact heat exchangers.

Practical implications

In this work, the capabilities of the proposed methodology to deal with industrial applications in the field of compact exchangers are outlined.

Originality/value

The paper presents an effective approach to the solution of conjugate conduction and convection problems with simultaneous heat and mass transfer. The formulation is completely general, even if the finite element method is used in the calculations.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 18 no. 7/8
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 June 2003

G. Comini, C. Nonino and S. Savino

By neglecting the influence of tubes, this paper adopts a simplified two‐dimensional approach to deal with laminar convection of air through wavy finned‐tube exchangers. Pressure…

Abstract

By neglecting the influence of tubes, this paper adopts a simplified two‐dimensional approach to deal with laminar convection of air through wavy finned‐tube exchangers. Pressure drop and heat transfer characteristics are investigated in the fully developed region of the flow channels between adjacent fins. The solutions are presented for several space ratios (height over length of a module) and two corrugation angles. They concern laminar flows both below and above the onset of the self‐sustained oscillations that precede the transition to turbulence. Fully developed velocity and thermal fields are computed by imposing anti‐periodic conditions at inlet/outlet sections of a single calculation cell. In the range of Reynolds numbers investigated, Nusselt numbers and friction factors first increase with space ratios (up to a value depending on the corrugation angle), then start decreasing with increasing space ratios.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 13 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 14 August 2007

G. Comini and S. Savino

Joint descriptions of both heat and mass transfer and thermodynamic aspects of air‐cooling applications cannot be easily found in the literature. Numerical analyses are a notable…

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Abstract

Purpose

Joint descriptions of both heat and mass transfer and thermodynamic aspects of air‐cooling applications cannot be easily found in the literature. Numerical analyses are a notable exception since suitable physical models and realistic boundary conditions are a prerequisite of accurate simulations. Thus, it is believed that the experience gained with numerical simulations might be of some help also to designers of air‐conditioning and drying systems. This paper seeks to address this issue.

Design/methodology/approach

In the text, the physical implications of governing equations and boundary conditions utilized in numerical simulations are extensively discussed. Particular attention is paid to the thermodynamically consistent definition of latent and sensible heat loads, and to the correct formulation of the heat and mass transfer analogy.

Findings

Comparisons of analytical and numerical results concerning forced flows of humid air over a cooled plate validate the assumptions made in numerical simulations, both for air‐conditioning applications (almost always characterized by low rates of mass convection) and drying applications (almost always characterized by high rates of mass convection).

Originality/value

Finally, with reference to the cold plate problem investigated here, the effects of the suction flow induced by condensation on the Nusselt number are quantified.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 17 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 3 August 2015

Carlo Nonino, Stefano Savino and Stefano Del Giudice

The purpose of this paper is to develop a simplified but accurate finite element procedure for the analysis of the conjugate conduction-convection heat transfer in cross-flow…

Abstract

Purpose

The purpose of this paper is to develop a simplified but accurate finite element procedure for the analysis of the conjugate conduction-convection heat transfer in cross-flow micro heat exchangers.

Design/methodology/approach

The velocity fields in single microchannels are calculated by solving the parabolised form of the momentum equations and later mapped onto the three-dimensional grid, corresponding to an appropriate portion of the micro heat exchanger, which is used for the solution of the energy equation in its elliptic form. To allow the use of finite elements elongated in the flow direction, layers of perpendicular microchannels can be meshed independently with grids that do not match at the common interface (domain decomposition).

Findings

An original and easy-to-implement method has been developed to deal with non-matching grids. Computed results show that increasing the number of microchannels per layer yields relative pressure drop increments that are larger than those displayed by the relative heat flow rates.

Research limitations/implications

The simplified procedure requires the assumption of constant thermophysical properties. The adopted domain decomposition technique yields non-symmetric system matrices.

Practical implications

The procedure can be very useful in the design of cross-flow micro heat exchangers.

Originality/value

The finite element procedure described in the paper requires only limited computational resources for the analysis of the conjugate conduction-convection heat transfer in cross-flow micro heat exchangers with a large number of microchannels per layer.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 25 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 5 August 2021

Noor Aishah Hassan, Suhaiza Zailani and Muhammad Khalilur Rahman

This study aims to investigate the effectiveness of integrated audit management and its impact on business sustainability for an emerging economy.

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Abstract

Purpose

This study aims to investigate the effectiveness of integrated audit management and its impact on business sustainability for an emerging economy.

Design/methodology/approach

Drawing on the dynamic capability and contingency theory, the authors investigated the factors on integrated audit management implementation using a sample of 104 certified Malaysian manufacturing firms. The collected data has been analysed using the partial least squares through the structural equation modelling technique.

Findings

The findings have revealed that human resource capability, technological capability and quality capability have a robust influence on the importance of the internal audit process, which, in turn, leads to integrated audit management effectiveness towards the outcome of business sustainability. The results have also indicated the mediating effect of the internal audit process on the research model.

Originality/value

The contribution from the empirical findings will provide productive insights to help manufacturing firms devise an effective integrated internal audit management system to ensure business sustainability and increase competitiveness advantages for an emerging economy.

Article
Publication date: 24 October 2021

Roberto Linzalone and Antonio Lerro

The concept of positional innovation – as one of the four innovation types of the Francis and Bessant’s “4P’s” model – is an effective product innovation strategy for producers of…

Abstract

Purpose

The concept of positional innovation – as one of the four innovation types of the Francis and Bessant’s “4P’s” model – is an effective product innovation strategy for producers of mature and credence goods as food products are. Despite the acknowledgement as one of the major industries worldwide, positional innovations about the food products are underexplored in the managerial literature. To fill this gap, this paper first develops a theoretical analysis of the concepts. Then, by adopting a case-study research methodology, it discloses the way a bakery small enterprise manages positional innovation. Theoretical and practical implications are finally introduced and discussed.

Design/methodology/approach

After a literature review about the role and the characteristics of the positional innovation, the paper presents a case study of definition and implementation of managerial actions and initiatives driven by positional innovation. The aim is not to report on an inductive study, but to use this example as a picture to clarify theory and show how the various conceptual issues may be operatively applied and provide more contextual insights.

Findings

It emerges how a small food enterprise manages positional innovation to survive and compete in the national and international markets; the positional innovation sources are tapped into culture, social responsibility, tradition and other territorial assets of tangible and intangible nature, effectively combined to innovate the product perception and/or the utility in a use context.

Originality/value

“Non-technological”, simple products, like food, are underexplored and rarely seen as relevant context to investigate along the strategic and innovation management literature. Nonetheless, positional innovation is a perspective that values and credits the innovation efforts of small food products, revealing interesting managerial concepts and inspiring entrepreneurs and managers for activating and sustaining new strategies of innovation for their businesses.

Details

Measuring Business Excellence, vol. 25 no. 4
Type: Research Article
ISSN: 1368-3047

Keywords

Article
Publication date: 1 September 2002

G. Comini, C. Nonino and S. Savino

The paper adopts a simplified two‐dimensional approach to deal with convective heat and mass transfer in laminar flows of humid air through wavy finned‐tube exchangers. The…

Abstract

The paper adopts a simplified two‐dimensional approach to deal with convective heat and mass transfer in laminar flows of humid air through wavy finned‐tube exchangers. The computational domain is spatially periodic, with fully developed conditions prevailing at a certain distance from the inlet section. Both the entrance and the fully developed flow region are investigated. In the fully developed region, periodicities in the flow, temperature and mass concentration fields are taken into account. The approach is completely general, even if the finite element method is used for the discretizations. In the application section, velocity, temperature, and mass concentration fields are computed first. Then apparent friction factors, Nusselt numbers, Colburn factors for heat and mass transfer, and goodness factors are evaluated both in the entrance and in the fully developed region.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 12 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 3 May 2016

Carlo Nonino and Stefano Savino

The purpose of this paper is twofold: to describe a relevant improvement to an in-house FEM procedure for the heat transfer analysis of cross-flow micro heat exchangers and to…

Abstract

Purpose

The purpose of this paper is twofold: to describe a relevant improvement to an in-house FEM procedure for the heat transfer analysis of cross-flow micro heat exchangers and to study the influence of microchannel cross-sectional geometry and solid wall thermal conductivity on the thermal performance of these microdevices.

Design/methodology/approach

The velocity field in each microchannel is calculated separately. Then the energy equation is solved in the whole computational domain. Domain decomposition and grids that do not match at the common interface are employed to make meshing more effective. Some flow maldistribution effects are taken into account.

Findings

The results show that larger thermal conductivities of the solid walls and rectangular cross-sectional geometries with higher aspect ratios allow the maximization of the total heat flow rate in the device. However, on the basis of the heat transfer per unit pumping power, the square cross-section could be the best option.

Research limitations/implications

The value of the average viscosity is assumed to be different in different microchannels, but constant within each of the microchannels.

Practical implications

The procedure can represent a valuable tool for the design of cross-flow micro heat exchangers.

Originality/value

In spite of requiring limited computational resources, the improved procedure can take into account flow maldistribution effects stemming from non-uniform microchannel temperatures.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 26 no. 3/4
Type: Research Article
ISSN: 0961-5539

Keywords

Book part
Publication date: 6 September 2021

Paul B. Lester

Despite the widespread attribution that stressful crucible experiences result in important individual developmental change within leaders, a deeper exploration of the mechanisms…

Abstract

Despite the widespread attribution that stressful crucible experiences result in important individual developmental change within leaders, a deeper exploration of the mechanisms of that change is warranted. Likewise, literature linking the crucible and individual change to social and organizational considerations, including how organizations can plan for and sponsor institutionalized crucibles, is sparse. Thus, the intent of this chapter is to begin to synthesize the crucible, cognitive development, and stress literatures to show important linkages, risks, and outcomes, then provide a basic blueprint of planning considerations for organizations that desire to establish their own crucible events that target leader development.

Details

Examining and Exploring the Shifting Nature of Occupational Stress and Well-Being
Type: Book
ISBN: 978-1-80117-422-0

Keywords

Article
Publication date: 10 April 2024

Adekunle Sabitu Oyegoke, Saheed Ajayi, Muhammad Azeem Abbas and Stephen Ogunlana

The lack of a proper register to store, match and display information on the adapted property has led to a waste of resources and prolonged delays in matching the disabled and…

Abstract

Purpose

The lack of a proper register to store, match and display information on the adapted property has led to a waste of resources and prolonged delays in matching the disabled and elderly people with appropriate properties. This paper presents the development of a Housing Adaptations Register with user-matching functionalities for different mobility categories. The developed system accurately captures and documents adapted home information to facilitate the automated matching of disabled/aged applicants needing an adapted home with suitable property using banding, mobility and suitability index.

Design/methodology/approach

A theoretical review was conducted to identify parameters and develop adaptations register construct. A survey questionnaire approach to rate the 111 parameters in the register as either moderate, desirable or essential before system development and application. The system development relied on DSS modelling to support data-driven decision-making based on the decision table method to represent property information for implementing the decision process. The system is validated through a workshop, four brainstorming sessions and three focus group exercises.

Findings

Development of a choice-based system that enables the housing officers or the Housing Adaptations Register coordinators to know the level of adaptation to properties and match properties quickly with the applicants based on their mobility status. The merits of the automated system include the development of a register to capture in real-time adapted home information to facilitate the automated matching of disabled/aged applicants. A “choice-based” system that can map and suggest a property that can easily be adapted and upgraded from one mobility band to the other.

Practical implications

The development of a housing adaptation register helps social housing landlords to have a real-time register to match, map and upgrade properties for the most vulnerable people in our society. It saves time and money for the housing associations and the local authorities through stable tenancy for adapted homes. Potentially, it will promote the independence of aged and disabled people and can reduce their dependence on social and healthcare services.

Originality/value

This system provides the local authorities with objective and practical tools that may be used to assess, score, prioritise and select qualified people for appropriate accommodation based on their needs and mobility status. It will provide a record of properties adapted with their features and ensure that matching and eligibility decisions are consistent and uniform.

Details

International Journal of Building Pathology and Adaptation, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2398-4708

Keywords

1 – 10 of 377