bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parallel computation of two‐dimensional laminar inert and chemically reactive multi‐species gas flows
Authors: Ess P.R. , Allen C.B. 
Published: January 2007

PurposeA computational fluid dynamics code for the calculation of laminar hypersonic multi‐species gas flows in chemical non‐equilibrium in axisymmetric or two‐dimensional configuration on shared and distributed memory parallel computers is presented and validated. The code is designed to work efficiently in combination with an automatic domain decompositioning method developed to facilitate efficient parallel computations of various flow problems.Design/methodology/approachThe baseline implicit numerical method developed is the lower‐upper symmetric Gauss‐Seidel scheme, which is combined with a sub‐iteration scheme to achieve time‐accuracy up to third‐order. The spatial discretisation is based on Roe's flux‐difference splitting and various non‐linear flux limiters maintaining total‐variation diminishing properties and up to third‐order spatial accuracy in continuous regions of flow. The domain subdivision procedure is designed to work for single‐ and multi‐block domains without being constrained by the block boundaries, and an arbitrary number of processors used for the computation.FindingsThe code developed reproduces accurately various types of flows, e.g. flow over a flat plate, diffusive mixing and oscillating shock induced combustion around a projectile fired into premixed gas, and demonstrates close to linear scalability within limits of load imbalance.Research limitations/implicationsThe cases considered are axisymmetric or two‐dimensional, and assume laminar flow. An extension to three‐dimensional turbulent flows is left for future work.Originality/valueResults of a parallel computation, utilising a newly developed automatic domain subdivision procedure, for oscillating shock‐induced combustion around a projectile and various other cases are presented. The influence of entropy correction in Roe's flux‐difference splitting algorithm on diffusive mixing of multi‐species flows was examined.
Numerical simulation of heat and fluid flow in basic pulse tube refrigerator
Authors: Koshimizu Takao , Kubota Hiromi , Takata Yasuyuki , Ito Takehiro 
Published: January 2007

PurposeTo clarify the physical working principle of refrigeration in basic pulse tube refrigerators (BPTRs).Design/methodology/approachA numerical simulation was performed. Transient compressible NS equation was solved utilizing the TVD scheme coupled with energy equation.FindingsThe periodic flow and temperature field were obtained. The movement of the gas particles and heat transfer between the gas particles and wall were analyzed. These numerical results explained the mechanism of surface heat pumping (SHP) which is known as the working principle of refrigeration in BPTR.Research limitations/implicationsPulse tube refrigerator (PTR) is classified into the third generation. BPTR is the first generation. It is needed to clarify the working principle of refrigeration in the second and third generation by analyzing heat and fluid flow in the tube.Practical implicationsA very useful source of information to understand the physical working principle of refrigeration in BPTR.Originality/valueThe mechanism of SHP was shown by analyzing the heat exchange between the gas particles and pulse tube wall.
A model of heat transfer dynamics of coupled multiphase‐flow and neutron‐radiation
Authors: Pain C.C. , Gomes J.L.M.A. , Eaton  , de Oliveira C.R.E. , Goddard A.J.H. 
Published: January 2007

PurposeTo present dynamical analysis of axisymmetric and three‐dimensional (3D) simulations of a nuclear fluidized bed reactor. Also to determine the root cause of reactor power fluctuations.Design/methodology/approachWe have used a coupled neutron radiation (in full phase space) and high resolution multiphase gas‐solid Eulerian‐Eulerian model.FindingsThe reactor can take over 5 min after start up to establish a quasi‐steady‐state and the mechanism for the long term oscillations of power have been established as a heat loss/generation mechanism. There is a clear need to parameterize the temperature of the reactor and, therefore, its power output for a given fissile mass or reactivity. The fission‐power fluctuates by an order of magnitude with a frequency of 0.5‐2 Hz. However, the thermal power output from gases is fairly steady.Research limitation/implicationsThe applications demonstrate that a simple surrogate of a complex model of a nuclear fluidised bed can have a predictive ability and has similar statistics to the more complex model.Practical implicationsThis work can be used to analyze chaotic systems and also how the power is sensitive to fluctuations in key regions of the reactor.Originality/valueThe work presents the first 3D model of a nuclear fluidised bed reactor and demonstrates the value of numerical methods for modelling new and existing nuclear reactors.
Particle number per cell and scaling factor effect on accuracy of DSMC simulation of micro flows
Authors: Shu C. , Mao X.H. , Chew Y.T. 
Published: January 2007

PurposeThis paper aims to give some guidance on the selection of particle numbers per cell and the number of molecules per particle in the micro flow simulation by using DSMC method.Design/methodology/approachThe numerical investigation is performed to study the effects of particle number per cell and the scaling factor of real molecules to a simulated particle on accuracy of DSMC simulation of two‐dimensional micro channel flows in the “slip flow” and “transition flow” regimes.FindingsNumerical results show that both the particle number per cell and the scaling factor have effect on the accuracy of the DSMC results from the statistical error and the physical aspects. In the “slip flow” regime, a larger value of scaling factor can be used to obtain accurate results as compared to the “transition flow” regime. However, in the “transition flow” regime, much less number of particles in each cell can be used to generate accurate DSMC results as compared to the “slip flow” regime.Research limitations/implicationsThe present work is limited to the two‐dimensional case.Practical implicationsThe results of this paper are very useful for the two‐dimensional micro flow simulation by DSMC.Originality/valueThe work in this paper is original and provides guidance on micro flow simulation.
Numerical investigation of heat transfer on film cooling with shaped holes
Authors: Zhang X.‐Z. , Hassan I. 
Published: January 2007

PurposeTo develop a reliable methodology and procedure of simulating the jet‐in‐crossflow using the current turbulence models and numerically investigate the cooling performance of a new scheme for the engines of next generation.Design/methodology/approachA new advanced film cooling scheme is proposed based on the literature survey and a systematic methodology developed to successfully predict the right level of heat transfer in the CFD simulation of film cooling.FindingsThe proposed cooling scheme gives considerable lower heat transfer coefficient at the centerline in the near hole region than the traditional cylindrical hole, especially at a high blowing ratio when traditional cylindrical hole undergoes liftoff.Research limitations/implicationsThe number of cooling holes in the computational domain is limited by the speed of the computers used.Practical implicationsThe new methodology can be used to numerically test new cooling schemes in the design of turbine blades and to provide useful information/data under actual working conditions to design engineers.Originality/valueThis paper provides some useful information on the simulation of film cooling in terms of the performance of different turbulence models and wall treatments and also sends some valuable messages regarding the design of cooling scheme of turbine blades to the technical community.
Modelling of strongly swirling flows in a complex geometry using unstructured meshes
Authors: Wang Junye , Priestman Geoffrey H. , Tippetts John R. 
Published: January 2007

PurposeSeeks to examine the performance of conventional turbulence models modelling strongly swirling flows within a Symmetrical Turn up Vortex Amplifier, with adjustment of the turbulence model constants to improve agreement with experimental data.Design/methodology/approachFirst, the standard k‐ε model and the Reynolds Stress Model (RSM) were used with standard values of model constants, using both the first order upwind and the quadratic upstream interpolation for convective kinetics (QUICK) schemes. Then, the swirling effect was corrected by adjusting the model coefficients.FindingsThe standard RSM with the QUICK did produce better predictions but still significantly overestimated the experimental data. Much improved simulation was obtained with the systematic adjustment of the model constants in the standard k‐ε model using the QUICK. The physical significance of the model constants accounted for changes of the eddy viscosity, and the production and destruction of k and ε.Research limitations/implicationsMore industrial cases could benefit from this simple and useful approach.Originality/valueThe constant adjustment is regular and directed, based on the eddy viscosity and the production and destruction of k and ε. The regularity of the effect of the model constants on the solutions makes it easier to quickly adjust them for other industrial applications.
Neuro‐genetic optimization of micro compact heat exchanger
Authors: Lee H.W. , Teng Y.J. , Azid I.A. , Seetharamu K.N. 
Published: January 2007

PurposeThis paper seeks to introduce an optimization method for maximizing the effectiveness of the micro compact heat exchanger (MHE) under various geometrical parameters.Design/methodology/approachOptimization is realized using the neuro‐genetic methodology which combines the application of artificial neural network (ANN) together with genetic algorithms (GA). The analyses are divided into two main sections; the first being the modeling and prediction using finite element method, the second being the neuro‐genetic optimization. Initial results obtained from the finite element modeling are utilized for training in ANN. Subsequently, optimization is done using GA, once a well trained ANN is achieved.FindingsANN accurately predicts the effectiveness of the MHE and compares well with those obtained from the finite element simulation. Optimization shows a significant improvement in the maximum effectiveness of the MHE achievable for the given range of input parameters. Additionally, computational effort has been minimized and simulation time has been drastically reduced.Research limitations/implicationsThis analysis is valid for constant fluid properties and for steady‐state conditions. Additionally, optimization is limited to the range of the trained input parameters.Practical implicationsThis paper is very useful for practical design of various types of heat exchangers.Originality/valueThis paper will be useful for the design of the MHE where its performance can be analyzed for a given range of geometries with minimal effort. This methodology will also be applicable for other types of heat exchangers.
Numerical simulation of two‐dimensional laminar mixed‐convection in a lid‐driven cavity using the mixed finite element consistent splitting scheme
Authors: Wong Jeff C.‐F. 
Published: January 2007

PurposeThe purpose of this paper is to propose an efficient/robust numerical algorithm for solving the two‐dimensional laminar mixed‐convection in a lid‐driven cavity using the mixed finite element (FE) technique.Design/methodology/approachA numerical algorithm was based on the so‐called consistent splitting scheme, which improved the numerical accuracy of the primitive variables. In order to obtain a stable solution, two choices of mixed FEs, the Taylor‐Hood and Crouzeix‐Raviart types, were used. Two mesh layouts were considered; uniform and non‐uniform.FindingsTo verify that the proposed scheme had a second‐order accuracy, some numerical results are presented and compared with the known solution. The answer was confirmative. Numerically accurate solutions were obtained for a fixed Prandtl number, Pr=0.71, for a range of the Reynolds number, Re from 100 to 3,000, and for a range of the Richardson number, Ri from 0.001 to 100. The results from these calculations, using the mixed FE consistent splitting scheme, agreed with the existing ones.Research limitations/implicationsFurther extensions of this work could include the influence of various choices of Reynolds numbers, Prandtl numbers and Richardson numbers, and the effect of aspect ratio.Originality/valueThe present work was the first to apply a mixed FE in association with the consistent splitting scheme to the mixed convection problem.
Work/life balance: senior management champions or laggards?
Authors: Drew Eileen , Murtagh Eamonn M. 
Published: January 2007

PurposeThis paper seeks to examine the experience of, and attitudes towards, work/life balance (WLB) by female and male senior managers in a major Irish organisation for which WLB is now a strategic corporate objective.Design/methodology/approachBoth quantitative and qualitative data were collected using an electronic questionnaire survey designed to obtain the views of female and male managers on strategies that would contribute to a better gender balance, promote diversity and raise leadership capacity in the organisation. Work/life balance emerged as a major issue in impeding the career progression of female managers. All female managers and a sample of male managers were surveyed. This paper concentrates on the responses of the two senior management grades below Executive Director on the issue and strategies to promote work/life balance. Additional qualitative data were drawn from interviews (with eight women and five men) and three focus group sessions with all male, all female and mixed gender groups.FindingsThe greatest obstacle to achieving WLB is seen as the “long hours” culture in which availing oneself of flexible options (e.g. working from home/reduced hours/flexitime) is incompatible with holding a senior management post. Many of the senior men have followed the “breadwinner” model by being able to delegate family and caring activities to their wives. This option has not been possible for the majority of women in senior posts. Hence, men seek WLB to resolve commuting/working time issues. Women want to avail themselves of more flexible arrangements for family/quality of life reasons. Both men and women in senior management recognise that their own careers would be seriously jeopardised by taking up WLB arrangements.Originality/valueIn the absence of role models willing to display any contrary behaviour there is a pragmatic need to align corporate policy and practice with prevailing and future family structures and demonstrate, by senior management example, how WLB can work and provide assistance for managers/staff who seek to avail themselves of it. WLB policies are not enough in themselves to ensure take‐up and acceptance. It will require trust, courage and a range of interventions to champion WLB, not just at management level.
Women, work, and Islam in Arab societies
Authors: Sidani Yusuf 
Published: January 2007

PurposeThis paper attempts to present varying discourses pertaining to women's work and how it is impacted by interpretations of Islam.Design/methodology/approachCurrent discourses from various viewpoints are presented including Muslim scholars on the one hand and active feminists on the other. Personalities are presented as being representative of the debate that has been going on pertaining to women in Arab societies.FindingsAttempts that aim at categorizing Arab thought and activism into two camps, one is religious‐based adverse to women's causes, and the other being secular and supportive of their causes does not present a candid depiction of the different forces.Research limitations/implicationsPersonalities chosen represent specific case studies that, although thought to be representative, cannot realistically reflect all the multitudes of views expressed pertaining to the issues discussed. Future studies may cover other relevant personalities in the region.Practical implicationsDeveloping the status of women in Arab societies requires a major reassessment of Muslim history and traditions. The dialogue and debates going on among religious scholars and feminists should be continuously communicated, discussed and exposed. Readers and mangers would benefit from understanding the complexity of issues and diversity of views presented.Originality/valueThis paper offers a window into the world of women's work and participation in Arab societies and how such participation is impacted by Islam, or its interpretations thereof. In addition to the English sources, this paper offers an opportunity for the reader to get a glimpse of the debate that has been going on in Arabic (especially when it comes to the little known religious discourse).
Exploring gender differences in leaders' occupational self‐efficacy
Authors: Schyns Birgit , Sanders Karin 
Published: January 2007

PurposeThis study focuses on gender differences in the relationship between transformational leadership and leader's occupational self‐efficacy. The aim is to explain how female and male leaders develop their self‐efficacy. This knowledge is important for leaders as well as organizations (e.g. human resources departments).Design/methodology/approachA total of 58 leaders were asked to indicate their transformational leadership as well as their occupational self‐efficacy, and 113 followers to indicate these leaders' transformational leadership. Hypotheses were examined using regression analyses.FindingsWe found no significant relationship between self‐rated transformational leadership and occupational self‐efficacy for women, although we did find a positive relationship for men. No interaction effect with respect to leaders' occupational self‐efficacy could be found between leaders' gender and follower‐rated transformational leadership.Research limitations/implicationsWhereas the relationship between transformational leadership and occupational self‐efficacy was examined for men and women, we could not examine the processes that lead to the differences.Practical implicationsKnowing that female and male leaders differ in the relationship between transformational leadership and occupational self‐efficacy can help organizations to seek ways to build up their occupational self‐efficacy. This is especially important when considering that occupational self‐efficacy is related to performance in organizations.Originality/valueThe paper employs both leader and follower evaluations on leaders' transformational leadership to explore the relationship between transformational leadership and occupational self‐efficacy. The paper sheds light on the different processes involved in establishing occupational self‐efficacy.
Organisational practices supporting women's career advancement and their satisfaction and well‐being in Turkey
Authors: Burke Ronald J. , Koyuncu Mustafa , Fiksenbaum Lisa 
Published: January 2007

PurposeThe purpose of this study is to examine the relationship of the perceived presence of organisational practices designed to support women's career advancement and their work attitudes and satisfaction and their psychological well‐being.Design/methodology/approachData were collected from 286 women in managerial and professional jobs working in a large Turkish bank, a 72 percent response rate. Five organisational experiences were considered: negative attitudes towards women, equal treatment, support, career barriers and male standards.FindingsWomen reporting more supportive organisational experiences and practices were more engaged in their work, more job and career satisfied, and indicated greater levels of psychological well‐being.Research limitations/implicationsData were collected at one point in time making it difficult to determine causality. It is important to replicate the study in other industries and countries to verify the generalizability of the conclusions.Practical implicationsIdentifies career supports and obstacles and offers guidance for organisations interested in supporting women's career advancement.Originality/valueThis study contributes to understanding of the role of work life experiences in women's work satisfaction and psychological well‐being.
A neuro‐fuzzy theoretic approach to safety control at crude oil exploration platforms
Authors: Oke S.A. , Johnson A.O. , Omogoroye O.O. 
Published: January 2007

PurposeThe purpose of this paper is to present a new approach in viewing the control of safety at crude oil exploration platforms.Design/methodology/approachThe approach utilized in this work is the fusion of artificial neural network and fuzzy logic. The approach is adopted in view of the better presentation of solutions to the safety control problem that neuro‐fuzzy exhibits. It is better than the individual application of either artificial neural network or fuzz logic to the problem at hand. The model captures uncertainties and imprecision that are prevalent in the quantification or data gathering stage of safety control measurement.FindingsIt was demonstrated that the application of neuro‐fuzzy is feasible. The results seem applicable to similar settings with similar system characteristics.Practical implicationsSince more confidence is obtained with the use of this more effective tool, there is improvement in decision making based on reliance on the model. Thus, the improved quality of decision made would positively affect lives of workers at the oil platforms or the materials or equipment used for exploration purposes.Originality/valueThe work is original in that it is the first time the neuro‐fuzzy methodology would be applied to offshore oil platform safety control.
Worldwide security measures for shipping, seafarers and ports
Authors: Goulielmos Alexandros M. , Anastasakos Agisilaos A. 
Published: January 2007

PurposeTo inform readers comprehensively and sufficiently about the new (July 1, 2004) legal regime of SOLAS/ISPS code concerning security of ports and ships.Design/methodology/approachThe paper estimates the code's impact on vessels' security and on ships' ownership and control as well as on seafarers.FindingsThe maritime security measures costing $626 million (and $168 million per year) had to be seen as the third pillar of the international shipping policy and to facilitate instead of obstructing free flow of international sea transport.Research limitations/implicationsThe very recent implementation of ISPS code made this paper prognostic in nature.Originality/valueThis is the first account of the new regime and is of interest to shipowners and ports, US and EU seafarers.