Parametric and V&V study in a fundamental CFD process: revisiting the lid-driven cavity flow

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mingming Ge ◽  
Xin-Lei Zhang ◽  
Kaleb Brookshire ◽  
Olivier Coutier-Delgosha
Keyword(s):  
Reynolds Number ◽  
Time Derivative ◽  
Cost Effective ◽  
Design Tool ◽  
Point Of View ◽  
Numerical Implementation ◽  
Computational Accuracy ◽  
Aircraft Structures ◽  
Content Type ◽  
Reynolds Number Effects

Purpose The openings on aircraft structures can be modeled from an aerodynamical point of view as lid-driven cavities (LDC). This paper aims to show the primary verification and validation (V&V) process in computational fluid dynamics (CFD, and to investigate the influences of numerical settings on the efficiency and accuracy for solving the LDC problem. Design/methodology/approach To dig into the details of CFD approaches, this paper outlines the design, implementation, V&V and results of an efficient explicit algorithm. The parametric study is performed thoroughly focusing on various iteration methods, grid density discretization terms and Reynolds number effects. Findings This study parameterized the numerical implementation which provides empirical insights into how computational accuracy and efficiency are affected by changing numerical settings. At a low Reynolds number (not over 1,000), the time-derivative preconditioning is necessary, and k = 0.1 can be the optimal value to guarantee the efficiency, as well as the stability. A larger artificial viscosity (c = 1/16) would relieve the calculating oscillation issue but proportionally increase the discretization error. Furthermore, the iteration method and the mesh quality are two key factors that affect the convergence efficiency, thus need to be selected “wisely”. Practical implications The study shows how numerical implementation can enhance an accurate and efficient solution. This workflow can be used to determine the best parameter settings whenever CFD researchers applying this LDC problem as a complementary design tool for testing newly developed solvers. Originality/value The studied LDC problem is representative of CFD analysis in real aircraft structures. These numerical simulations provide a cost-effective and convenient tool to understand the parameter sensitivity, solution receptivity and physics of the CFD process.

BisGMA/EPDM/amine functionalised MWCNTs based nanocomposites

2015 ◽  
Vol 44 (5) ◽  
pp. 266-275 ◽  
Author(s):  
Ankita Pritam Praharaj ◽  
Dibakar Behera ◽  
Tapan Kumar Bastia ◽  
Arun Kumar Rout
Keyword(s):  
Water Absorption ◽  
Low Cost ◽  
Cost Effective ◽  
Point Of View ◽  
Content Type ◽  
Wide Range ◽  
Multi Walled Carbon Nanotubes ◽  
Thermal And Electrical Properties ◽  
Electrical Materials ◽  
Walled Carbon Nanotubes

Purpose – This paper aims to focus on the development and study properties of bisphenol-A glycidyldimethacrylate (BisGMA) and ethylene–propylene–diene monomer (EPDM) blend-based nanocomposites containing amine-functionalised multi-walled carbon nanotubes (MWCNT-NH2) as a compatibiliser. Design/methodology/approach – First, BisGMA was synthesised from epoxy and methacrylic acid followed by the amine functionalisation of MWCNTs. A novel two-roll milling technique was then conducted to prepare nanocomposite specimens with MWCNT-NH2 as compatibiliser. Effect of MWCNT-NH2 content on the mechanical, thermal, electrical, corrosive and water absorption properties of the nanocomposites was investigated and results have been reported. Findings – The results of the present work reveal that MWCNT-NH2 acts as a potential compatibiliser and nanofiller in BisGMA/EPDM blend-based nanocomposites. The authors report here that the nanocomposites exhibit improved mechanical, thermal and electrical properties with increased addition of MWCNT-NH2. Moreover, desirable results are obtained at 5 phr of nanofiller loading beyond which the properties deteriorate due to particle agglomeration. The nanocomposites display negligible corrosion and water absorption characteristics. Thus, the above fabricated nanocomposites with optimum compatibiliser content can serve as low-cost structural, thermal and electrical materials which can also be utilised in corrosive and moist environments. Research limitations/implications – The present investigation has come up with the successful and cost-effective fabrication of BisGMA/EPDM blend-based nanocomposites with optimum nanofiller/compatibiliser (MWCNT-NH2) content that can be used for a wide range of structural, thermal and electrical projects, as it is corrosion and moisture resistant. It is also the most durable from the mechanical point of view. Originality/value – The above nanocomposites have never been designed before.

The Role of Economic Evaluation in Dissemination and Implementation Research

2017 ◽  
Author(s):  
Ramesh Raghavan
Keyword(s):  
Service Providers ◽  
Implementation Strategies ◽  
Cost Effective ◽  
Point Of View ◽  
Dissemination And Implementation ◽  
Economic Point ◽  
Open Questions ◽  
Public Health Organizations ◽  
Quality Health ◽  
Dissemination And Implementation Research

This chapter presents an overview of how D&I research can be evaluated from an economic point of view. Dissemination and implementation imposes costs upon knowledge purveyors, provider organizations, public health organizations, and payers (including governments). However, whether these added costs will result in improved service delivery and, perhaps more importantly, client outcomes and improvements in population health remain as open questions. If emerging studies reveal that defined implementation strategies are more cost effective than “usual” implementation, then policymakers and service providers will need to resource these added costs of implementation in order to assure the success and sustainability of high-quality health services over the long term.

The cost-effectiveness of insulin analogs and regular insulin for diabetes control: a case study in Iran

2020 ◽  
Vol 33 (4/5) ◽  
pp. 323-331
Author(s):  
Mohsen pakdaman ◽  
Raheleh akbari ◽  
Hamid reza Dehghan ◽  
Asra Asgharzadeh ◽  
Mahdieh Namayandeh
Keyword(s):  
Cost Effectiveness ◽  
Cost Effective ◽  
Regular Insulin ◽  
Diabetes Control ◽  
Diabetic Patients ◽  
Insulin Analogs ◽  
Content Type ◽  
Patients With Diabetes ◽  
The Government ◽  
The Cost

PurposeFor years, traditional techniques have been used for diabetes treatment. There are two major types of insulin: insulin analogs and regular insulin. Insulin analogs are similar to regular insulin and lead to changes in pharmacokinetic and pharmacodynamic properties. The purpose of the present research was to determine the cost-effectiveness of insulin analogs versus regular insulin for diabetes control in Yazd Diabetes Center in 2017.Design/methodology/approachIn this descriptive–analytical research, the cost-effectiveness index was used to compare insulin analogs and regular insulin (pen/vial) for treatment of diabetes. Data were analyzed in the TreeAge Software and a decision tree was constructed. A 10% discount rate was used for ICER sensitivity analysis. Cost-effectiveness was examined from a provider's perspective.FindingsQALY was calculated to be 0.2 for diabetic patients using insulin analogs and 0.05 for those using regular insulin. The average cost was $3.228 for analog users and $1.826 for regular insulin users. An ICER of $0.093506/QALY was obtained. The present findings suggest that insulin analogs are more cost-effective than regular insulin.Originality/valueThis study was conducted using a cost-effectiveness analysis to evaluate insulin analogs versus regular insulin in controlling diabetes. The results of study are helpful to the government to allocate more resources to apply the cost-effective method of the treatment and to protect patients with diabetes from the high cost of treatment.

scholarly journals Comparison between Concentrated Solar Power and Gas-Based Generation in Terms of Economic and Flexibility-Related Aspects in Chile

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1063
Author(s):  
Catalina Hernández Moris ◽  
Maria Teresa Cerda Guevara ◽  
Alois Salmon ◽  
Alvaro Lorca
Keyword(s):  
Natural Gas ◽  
Solar Power ◽  
Renewable Energy Sources ◽  
Cost Effective ◽  
Hybrid Plant ◽  
Point Of View ◽  
Concentrated Solar Power ◽  
Economic Point ◽  
Hybrid Plants ◽  
Cost Of Energy

The energy sector in Chile demands a significant increase in renewable energy sources in the near future, and concentrated solar power (CSP) technologies are becoming increasingly competitive as compared to natural gas plants. Motivated by this, this paper presents a comparison between solar technologies such as hybrid plants and natural gas-based thermal technologies, as both technologies share several characteristics that are comparable and beneficial for the power grid. This comparison is made from an economic point of view using the Levelized Cost of Energy (LCOE) metric and in terms of the systemic benefits related to flexibility, which is very much required due to the current decarbonization scenario of Chile’s energy matrix. The results show that the LCOE of the four hybrid plant models studied is lower than the LCOE of the gas plant. A solar hybrid plant configuration composed of a photovoltaic and solar tower plant (STP) with 13 h of storage and without generation restrictions has an LCOE 53 USD/MWh, while the natural gas technology evaluated with an 85% plant factor and a variable fuel cost of 2.0 USD/MMBtu has an LCOE of 86 USD/MWh. Thus, solar hybrid plants under a particular set of conditions are shown to be more cost-effective than their closest competitor for the Chilean grid while still providing significant dispatchability and flexibility.

Comparison of the reluctance laminated and solid rotor synchronous machine operating at high temperatures

2019 ◽  
Vol 38 (4) ◽  
pp. 1111-1119 ◽  
Author(s):  
Marcin Lefik ◽  
Krzysztof Komeza ◽  
Ewa Napieralska-Juszczak ◽  
Daniel Roger ◽  
Piotr Andrzej Napieralski
Keyword(s):  
High Speed ◽  
Design Methodology ◽  
Three Dimensional ◽  
Synchronous Machine ◽  
Point Of View ◽  
Heat Sources ◽  
Model Calculations ◽  
Content Type ◽  
Thermal Phenomenon ◽  
Practical Implications

Purpose The purpose of this paper is to present a comparison between reluctance synchronous machine-enabling work at high internal temperature (HT° machine) with laminated and solid rotor. Design/methodology/approach To obtain heat sources for the thermal model, calculations of the electromagnetic field were made using the Opera 3D program including effect of rotation and the resulting eddy current losses. To analyse the thermal phenomenon, the 3D coupled thermal-fluid (CFD) model is used. Findings The presented results show clearly that laminated construction is much better from a point of view of efficiency and temperature. However, solid construction can be interesting for high speed machines due to their mechanical robustness. Research limitations/implications The main problem, despite the use of parallel calculations, is the long calculation time. Practical implications The obtained simulation and experimental results show the possibility of building a machine operating at a much higher ambient temperature than it was previously produced for example in the vicinity of the aircraft turbines. Originality/value The paper presents the application of fully three-dimensional coupled electromagnetic and thermal analysis of new machine constructions designed for elevated temperature.

Heat transfer enhancement using second mode self-oscillating structures

2019 ◽  
Vol 30 (7) ◽  
pp. 3827-3842
Author(s):  
Samer Ali ◽  
Zein Alabidin Shami ◽  
Ali Badran ◽  
Charbel Habchi
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Laminar Flow ◽  
Flow Regime ◽  
Vortex Generator ◽  
Reynolds Numbers ◽  
Content Type ◽  
Laminar Flow Regime ◽  
Second Mode

Purpose In this paper, self-sustained second mode oscillations of flexible vortex generator (FVG) are produced to enhance the heat transfer in two-dimensional laminar flow regime. The purpose of this study is to determine the critical Reynolds number at which FVG becomes more efficient than rigid vortex generators (RVGs). Design/methodology/approach Ten cases were studied with different Reynolds numbers varying from 200 to 2,000. The Nusselt number and friction coefficients of the FVG cases are compared to those of RVG and empty channel at the same Reynolds numbers. Findings For Reynolds numbers higher than 800, the FVG oscillates in the second mode causing a significant increase in the velocity gradients generating unsteady coherent flow structures. The highest performance was obtained at the maximum Reynolds number for which the global Nusselt number is improved by 35.3 and 41.4 per cent with respect to empty channel and rigid configuration, respectively. Moreover, the thermal enhancement factor corresponding to FVG is 72 per cent higher than that of RVG. Practical implications The results obtained here can help in the design of novel multifunctional heat exchangers/reactors by using flexible tabs and inserts instead of rigid ones. Originality/value The originality of this paper is the use of second mode oscillations of FVG to enhance heat transfer in laminar flow regime.

Job crafting, workplace civility and work outcomes: the mediating role of work engagement

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anuj Gupta ◽  
Pankaj Singh
Keyword(s):  
Life Satisfaction ◽  
Work Engagement ◽  
Cost Effective ◽  
Job Crafting ◽  
Intention To Quit ◽  
Work Outcomes ◽  
Equation Modeling ◽  
Content Type ◽  
General Life Satisfaction ◽  
Workplace Civility

Purpose The antecedents and consequences of work engagement have been extensively discussed and analyzed in the previous literature; however, identifying cost-effective measures that can sustain work engagement to boost work outcomes has received sparse attention in the Indian information technology (IT) context. This study aims to provide new insights concerning the associations of job crafting and workplace civility with work engagement and its corresponding outcomes, such as change perception, general life satisfaction and intention to quit. Design/methodology/approach Hypotheses were tested using structural equation modeling on data obtained from 369 software developers in India using questionnaire surveys. Findings Results confirmed that work engagement partially mediated the association of job crafting and workplace civility with the perception of change and general life satisfaction. The negative associations of job crafting and workplace civility with the intention to quit were also partially mediated by work engagement. The findings can be used to inform human resources strategies to boost work engagement and subsequent work outcomes. Research limitations/implications The results of this empirical work will offer insights to managers who are looking for cost-effective interventions and behaviors aimed at increasing work engagement and, consequently, achieving effective work outcomes. Originality/value This study contributes by empirically testing the application of novel employee-driven practices in improving work engagement and work outcomes, particularly in the context of IT companies in India.

Journey towards best practices in acting on early warning signs in complex projects within a Russian context

2015 ◽  
Vol 8 (4) ◽  
pp. 828-843 ◽  
Author(s):  
Gulnara Sharaborova ◽  
Derek H.T. Walker ◽  
Guinevere Gilbert
Keyword(s):  
Early Warning ◽  
Point Of View ◽  
Warning Signs ◽  
Theory And Practice ◽  
Doctoral Study ◽  
Content Type ◽  
Early Warning Signs ◽  
Complex Projects ◽  
Research Findings ◽  
Phd Thesis

Purpose – The purpose of this paper is to provide a summary report and reflect on a recently passed PhD thesis (Sharaborova, 2014b) related to project management topics. Design/methodology/approach – This paper focussed on narrative reflection upon the completed doctoral journey. Findings – This paper presents the thesis findings, the research models, the guide in dealing with the early warning signs that developed as a result of this research and the contribution made to theory and practice. Research limitations/implications – Limitations of the research and the perspectives of the further diffusion of the research findings are considered. Originality/value – This TRN is a PhD candidate’s point of view as well as the opinions of the scientific research supervisors about the doctoral study and its outcome. The paper could be useful for novice researchers who wish to conduct their research and did not yet make a decision.

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