E. Dick and J. Steelant
A comparison of the accuracy of the central discretization scheme withartificial dissipation and the upwind flux‐difference TVD scheme has beenmade for the compressible…
Abstract
A comparison of the accuracy of the central discretization scheme with artificial dissipation and the upwind flux‐difference TVD scheme has been made for the compressible Navier‐Stokes equations for high Reynolds number flows. First, a comparison is made on two one‐dimensional model problems. Then the schemes are compared on flat plate boundary layer flow. It is shown that a central scheme basically has poor accuracy due to the isotropic nature of the artificial dissipation. An upwind scheme decomposes the flow into different components and adapts the dissipation to the velocity of the components. The associated ansitropic dissipation results in a good accuracy. It is further discussed how a central discretization scheme with artificial dissipation can be improved at the expense of the same complexity of an upwind scheme.
Details
Keywords
J. Steelant and E. Dick
The steady compressible Navier—Stokes equations coupled to thek—ε turbulence equations are discretized within avertex‐centered finite volume formulation. The convective fluxes…
Abstract
The steady compressible Navier—Stokes equations coupled to the k—ε turbulence equations are discretized within a vertex‐centered finite volume formulation. The convective fluxes are obtained by the polynomial flux‐difference splitting upwind method. The first order accurate part results directly from the splitting. The second order part is obtained by the flux‐extrapolation technique using the minmod limiter. The diffusive fluxes are discretized in the central way and are split into a normal and a tangential contribution. The first order accurate part of the convective fluxes together with the normal contribution of the diffusive fluxes form a positive system which allows solution by classical relaxation methods. The source terms in the low‐Reynolds k‐ε equations are grouped into positive and negative terms. The linearized negative source terms are added to the positive system to increase the diagonal dominance. The resulting positive system forms the left hand side of the equations. The remaining terms are put in the right hand side. A multigrid method based on successive relaxation, full weighting, bilinear interpolation and W‐cycle is used. The multigrid method itself acts on the left hand side of the equations. The right hand side is updated in a defect correction cycle.
Details
Keywords
Konrad Nering and Kazimierz Rup
For internal flows with small values of the Reynolds number, there is often at a considerable distance from the pipe inlet cross-section a change of the flow form from laminar to…
Abstract
Purpose
For internal flows with small values of the Reynolds number, there is often at a considerable distance from the pipe inlet cross-section a change of the flow form from laminar to turbulent. To describe this phenomenon of laminar-turbulent transition in the pipe, also parallel-plate channel flow, a modified algebraic intermittency model was used. The original model for bypass transition developed by S. Kubacki and E. Dick was designed for simulating bypass transition in turbomachinery.
Design/methodology/approach
A modification of mentioned model was proposed. Modified model is suitable for simulating internal flows in pipes and parallel-plate channels. Implementation of the modified model was made using the OpenFOAM framework. Values of several constants of the original model were modified.
Findings
For selected Reynolds numbers and turbulence intensities (Tu), localization of laminar breakdown and fully turbulent flow was presented. Results obtained in this work were compared with corresponding experimental results available in the literature. It is particularly worth noting that asymptotic values of wall shear stress in flow channels and asymptotic values of axis velocity obtained during simulations are similar to related experimental and theoretical results.
Originality/value
The modified model allows precision numerical simulation in the area of transitional flow between laminar, intermittent and turbulent flows in pipes and parallel-plate channels. Proposed modified algebraic intermittency model presented in this work is described by a set of two additional partial differential equations corresponding with k-omega turbulence model presented by Wilcox (Wilcox, 2006).
In recent years, the use of dating and hook up apps has become an increasingly socially acceptable and commonly used method of seeking romantic and sexual partners. This has seen…
Abstract
In recent years, the use of dating and hook up apps has become an increasingly socially acceptable and commonly used method of seeking romantic and sexual partners. This has seen a corresponding rise in media and crime reports of sexual harms facilitated through these services, including sexual harassment, unsolicited sexual imagery, and sexual assault. Emerging empirical research shows that experiences of sexual harms in this context are common and predominantly impact women and girls. The aim of this chapter is to examine the sociocultural and sexual norms that underpin online dating and which perpetuate a “rape culture” within which sexual harms become both possible and normalized. This chapter also considers how the discourses that minimize and legitimize sexual harms are encoded within the responses undertaken by dating and hook up apps to sexual harms. It is argued that together these norms and discourses may act to facilitate and/or prevent sexual harms, and may normalize and excuse these harms when they occur.
Details
Keywords
Dick E. Zoutman and B. Douglas Ford
The purpose of this paper is to examine quality improvement (QI) initiatives in acute care hospitals, the factors associated with success, and the impacts on patient care and…
Abstract
Purpose
The purpose of this paper is to examine quality improvement (QI) initiatives in acute care hospitals, the factors associated with success, and the impacts on patient care and safety.
Design/methodology/approach
An extensive online survey was completed by senior managers responsible for QI. The survey assessed QI project types, QI methods, staff engagement, and barriers and factors in the success of QI initiatives.
Findings
The response rate was 37 percent, 46 surveys were completed from 125 acute care hospitals. QI initiatives had positive impacts on patient safety and care. Staff in all hospitals reported conducting past or present hand-hygiene QI projects and C. difficile and surgical site infection were the next most frequent foci. Hospital staff not having time and problems with staff prioritizing QI with other duties were identified as important QI barriers. All respondents reported hospital leadership support, data utilization and internal champions as important QI facilitators. Multiple regression models identified nurses’ active involvement and medical staff engagement in QI with improved patient care and physicians’ active involvement and medical staff engagement with greater patient safety.
Practical implications
There is the need to study how best to support and encourage physicians and nurses to become more engaged in QI.
Originality/value
QI initiatives were shown to have positive impacts on patient safety and patient care and barriers and facilitating factors were identified. The results indicated patient care and safety would benefit from increased physician and nurse engagement in QI initiatives.
Details
Keywords
S. Kubacki and E. Dick
This paper aims to provide improvements to the newest version of the k‐ ω turbulence model of Wilcox for convective heat transfer prediction in turbulent axisymmetric jets…
Abstract
Purpose
This paper aims to provide improvements to the newest version of the k‐ ω turbulence model of Wilcox for convective heat transfer prediction in turbulent axisymmetric jets impinging onto a flat plate.
Design/methodology/approach
Improvements to the heat transfer prediction in the impingement zone are obtained using the stagnation flow parameter of Goldberg and the vortex stretching parameter of Wilcox. The third invariant of the strain rate tensor in the form of Shih et al. and the blending function of Menter are applied in order make negligible the influence of the impingement modifications in the benchmark flows for turbulence models. Further, it is demonstrated that for two‐dimensional jets impinging onto a flat plate the stagnation region Nusselt number predicted by the original k‐ ω model is in good agreement with direct numerical simulation (DNS) and experimental data. Also for two‐dimensional jets, the proposed modification is deactivated.
Findings
The proposed modification has been applied to improve the convective heat transfer predictions in the stagnation flow regions of axisymmetric jets impinging onto a flat plate with nozzle‐plate distances H/D = 2, 6, 10 and Reynolds numbers Re = 23,000 and 70,000. Comparison of the predicted and experimental mean and fluctuating velocity profiles is performed. The heat transfer rates along a flat plate are compared to experimental data. Significant improvements are obtained with respect to the original k‐ ω model.
Originality/value
The proposed modification is simple and can be added to the k‐ ω model without causing stability problems in the computations.
Details
Keywords
Amin Khalifeh, Peter Farrell, Mohammad Alrousan, Shaima Alwardat and Masar Faisal
The paper aims to present a conceptual framework that helps in incorporating sustainability into software projects, highlights the importance of project sustainability and…
Abstract
Purpose
The paper aims to present a conceptual framework that helps in incorporating sustainability into software projects, highlights the importance of project sustainability and provides an extensive review of recent relevant contributions across various fields.
Design/methodology/approach
The authors carried out a systematic bibliographic search on relevant published materials to analyse links between the two disciplines (sustainability and software projects). Furthermore, content analysis was applied to the final selected publications to identify and classify relevant triple bottom line (TBL) aspects to develop the framework.
Findings
The inclusion of TBL-related aspects is the most efficient and effective method used to incorporate sustainability into projects. Most of the relevant contributions in the software literature have focussed on either project product or project process or on one or two dimensions of sustainability rather than the three dimensions of the TBL theory. This study contributes by proposing a conceptual framework that encompasses TBL-related aspects for incorporating sustainability into processes and products of software projects.
Research limitations/implications
Validating the proposed framework empirically could be an interesting research issue. In addition, future works may focus on different types of industries, such as information systems, telecommunications and service sectors, which have seldom been studied in the literature.
Practical implications
Software companies – or other relevant organisations – may use the proposed framework as a measurement tool to evaluate the environmental and social impacts of their current products and project management practices. Consequently, these organisations may pay more attention to incorporating sustainability into their project management practices.
Originality/value
The proposed framework may contribute towards a more sustainable orientation by providing a unique combination of TBL-related aspects that gives academics and practitioners a better understanding of how software projects can be managed sustainably.
Details
Keywords
Ekaterina A. Isaeva, Alexey V. Shleenko, Alexandra A. Chudaeva, Irina N. Shvetsova and Ilya E. Pokamestov
The planning of the strategic regions' development is hampered by numerous uncertainty factors, which creates problems for public administration bodies. This research aims to…
Abstract
The planning of the strategic regions' development is hampered by numerous uncertainty factors, which creates problems for public administration bodies. This research aims to develop a method for assessing the abilities of the region's economic system to adapt to uncertain conditions as a methodological basis for implementing public administration measures. The authors conducted a study of the dynamics of the development of the federal districts of Russia in 2019–2021. The conducted study revealed the heterogeneity of the reaction of regional economic systems to the impact of uncertainty factors, although the overall dynamics of the country's development were positive. The research methodology includes the determination of relative changes in the main indicators of socioeconomic development of regions and their contribution to the country-wide dynamics from the beginning of the occurrence of uncertainty factors to the recovery stage; their adjustment, considering the rigidity indicators; ranking of regions by the level of adaptability of the economic system; development of a differentiated set of measures to improve the adaptability of each type of economic systems. The authors determined that a high level of rigidity causes a low adaptability of the economic system to changes. The authors tested the methodology for assessing the adaptability of the economic system on the example of the federal districts of Russia. The authors distinguish three types of regional economic systems, depending on their adaptability, and apply a differentiated approach to substantiating regional policy measures.
Details
Keywords
Clauirton Siebra, Paulo Costa, Fabio Q.B. da Silva, André L.M. Santos and Angélica Mascaro
The set of services provided by the mobile phone platform, is becoming increasingly complex and requiring more computing power, hence higher energy consumption, and compromising…
Abstract
Purpose
The set of services provided by the mobile phone platform, is becoming increasingly complex and requiring more computing power, hence higher energy consumption, and compromising the autonomy of these devices. The purpose of this paper is to identify scenarios where methods could be applied to reduce such consumption and extend the mobile autonomy.
Design/methodology/approach
This mobile evolution has given rise to a lot of energy saving research activities, which mainly focus on the hardware side of computational systems. However, it is tempting to suppose that only hardware dissipates power, not software. This paper characterizes several hardware and software scenarios, which could be explored to develop energy‐efficient mobile techniques.
Findings
From this analysis, the authors argue that the development of applications that consider energy saving as one of their requirements, can result in a significant final energy saving because solutions will be part of their own software and they do not depend on external resources to obtain a lower consumption.
Originality/value
This paper provides a broad analysis about the different research directions in energy consumption optimization and stresses the important contributions that the software engineering area could offer to this subject.
Details
Keywords
Sylwiusz Retowski, Dorota Godlewska-Werner and Rolf van Dick
The study aimed to test the validity and reliability of the Polish version of the identity leadership inventory (ILI) proposed by Steffens, Haslam, Reicher et al. (2014) and to…
Abstract
Purpose
The study aimed to test the validity and reliability of the Polish version of the identity leadership inventory (ILI) proposed by Steffens, Haslam, Reicher et al. (2014) and to confirm the relationship between identity leadership and various job-related outcomes (i.e., trust in leaders, job satisfaction, work engagement and turnover intentions) among employees from Poland-based organizations. Identity leadership appears to be a universal construct (van Dick, Ciampa, & Liang, 2018) but no one has studied it in Poland so far.
Design/methodology/approach
The sample consisted of 1078 employees collected in two independent subsamples from different organizations located in Northern and Central Poland. We evaluated the ILI’s factorial structure using confirmatory factor analysis.
Findings
The results confirm that the 15-item Polish version of the ILI has a four-dimensional structure with factors representing prototypicality, advancement, entrepreneurship and impresarioship. It showed satisfactory reliability. The identity leadership inventory-short form (four items) also showed a good fit with the data. As expected, the relationships between identity leadership and important work-related outcomes (general level of job satisfaction, work engagement, trust toward the leader and turnover intentions) were also significant.
Originality/value
Despite the cultural specifics of Polish organizations, the research results were generally very similar to those in other countries, confirming the universality of the ILI as shown in the Global Identity Leadership Development project (GILD, see van Dick, Ciampa, & Liang, 2018; van Dick et al., 2021).