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Subcooled flow boiling phenomenon is characterized by coolant phase change in the vicinity of the heated wall. Although coolant phase change from liquid to vapour phase significantly enhances the heat transfer coefficient due to latent heat of vaporization, eventually the formed vapor bubbles may coalesce and deteriorate the heat transfer from the heated wall to the liquid phase. Due to the poor heat transfer characteristics of the vapour phase, the heat transfer rate drastically reduces when it reaches a specific value of wall heat flux. Such a threshold value is identified as critical heat flux (CHF), and the phenomenon is known as departure from nucleate boiling (DNB). An accurate prediction of CHF and its location is critical to the safe operation of nuclear reactors. Therefore, the present study aims at the prediction of DNB type CHF in a hexagonal sub-assembly.

Computational fluid dynamics (CFD) simulations are performed to predict DNB in a hexagonal sub-assembly. The methodology uses an Eulerian–Eulerian multiphase flow (EEMF) model in conjunction with multiple size group (MuSiG) model. The breakup and coalescence of vapour bubbles are accounted using a population balance approach.

Bubble departure diameter parameters in EEMF framework are recalibrated to simulate the near atmospheric pressure conditions. The predictions from the modified correlation for bubble departure diameter are found to be in good agreement against the experimental data. The simulations are further extended to investigate the influence of blockage (b) on DNB type CHF at low operating pressure conditions. Larger size vapour bubbles are observed to move away from the corner sub-channel region due to the presence of blockage. Corner sub-channels were found to be more prone to experience DNB type CHF compared to the interior and edge sub-channels.

An accurate prediction of CHF and its location is critical to the safe operation of nuclear reactors. Moreover, a wide spectrum of heat transfer equipment of engineering interest will be benefited by an accurate prediction of wall characteristics using breakup and coalescence-based models as described in the present study.

Simulations are performed to predict DNB type CHF. The EEMF and wall heat flux partition model framework coupled with the MuSiG model is novel, and a detailed variation of the coolant velocity, temperature and vapour volume fraction in a hexagonal sub-assembly was obtained. The present CFD model framework was observed to predict the onset of vapour volume fraction and DNB type CHF. Simulations are further extended to predict CHF in a hexagonal sub-assembly under the influence of blockage. For all the values of blockage, the vapour volume fraction is found to be higher in the corner region, and thus the corner sub-channel experiences CHF. Although DNB type CHF is observed in corner sub-channel, it is noticed that the presence of blockage in the interior sub-channel promotes the coolant mixing and results in higher values of CHF in the corner sub-channel.

The purpose of this paper is to achieve high‐performance aerofoils that enable delayed stall conditions and achieve high lift to drag ratios.

The unsteady Reynolds averaged Navier‐Stokes equations are employed in conjunction with a shear stress transport (κ‐ω) turbulence model. A control equation is designed and implemented to determine the temporal response of the actuator. A rotating element, in the form of an actuator disc, is embedded on the leading edge of NACA 0012 aerofoil, to inject momentum into the wake region. The actuator disc is rotated at different angular speeds, for angles of attack (α) between 00 and 240.

Phenomena such as flow separation, wake vortices, delayed stall, wake control, etc. are numerically investigated by means of streamlines, streaklines, isobars, etc. Streamwise and cross‐stream forces on the aerofoil are obtained. The influence of momentum injection parameter (ξ) on the fluid flow patterns, and hence on the forces acting on the streamlined body are determined. A synchronization‐based coupling scheme is designed and implemented to achieve annihilation of wake vortices. A delayed stall angle resulted with an attendant increase in maximum lift coefficient. Due to delay and/or prevention of separation, drag coefficient is also reduced considerably, resulting in a high‐performance lifting surface.

The practicality of momentum injection principle requires both wide ranging and intensive further studies to move forward beyond the proof of concept stage.

Determination of forces and moments on an aerofoil is of vital interest in aero‐dynamic design. Perhaps, runways of the future can be shorter and/or more pay load can be carried by an aircraft, for the same stall speed.

The paper describes how a synchronization‐based coupling scheme is designed and implemented along with the RANS solver. Furthermore, it is tested to verify the dynamic adaptability of the wake vortex annihilation for NACA 0012 aerofoils.

Better membrane oxygenators need to be developed to enable efficient gas exchange between venous blood and air.

Optimal design and analysis of such devices are achieved through mathematical modeling tools such as computational fluid dynamics (CFD). In this study, a control volume-based one-dimensional (1D) sub-channel analysis code is developed to analyze the gas exchange between the hollow fiber bundle and the venous blood. DIANA computer code, which is popular with the thermal hydraulic analysis of sub-channels in nuclear reactors, was suitably modified to solve the conservation equations for the blood oxygenators. The gas exchange between the tube-side fluid and the shell-side venous blood is modeled by solving mass, momentum and species conservation equations.

Simulations using sub-channel analysis are performed for the first time. As the DIANA-based approach is well known in rod bundle heat transfer, it is applied to membrane oxygenators. After detailed validations, the artificial membrane oxygenator is analyzed for different bundle sizes (L/W) and bundle porosity (epsilon) values, and oxygen saturation levels are predicted along the bundle. The present sub-channel analysis is found to be reasonably accurate and computationally efficient when compared to conventional CFD calculations.

This approach is promising and has far-reaching ramifications to connect and extend a well-known rod bundle heat transfer algorithm to a membrane oxygenator community. As a variety of devices need to be analyzed, simplified approaches will be attractive. Although the 1D nature of the simulations facilitates handling complexity, it cannot easily compete with expensive and detailed CFD calculations.

This work has high practical value and impacts the design community directly. Detailed numerical simulations can be validated and benchmarked for future membrane oxygenator designs.

Future membrane oxygenators can be designed and analyzed easily and efficiently.

The DIANA algorithm is popularly used in sub-channel analysis codes in rod bundle heat transfer. This efficient approach is being implemented into membrane oxygenator community for the first time.

Flow past an isolated circular cylinder and two cylinders in tandem is numerically simulated, under the influence of buoyancy aiding and opposing the flow. A modified velocity correction method is employed, which has second order accuracy in both space and time. The influence of buoyancy on the temporal fluid flow patterns is investigated, with respect to streamlines, isotherms and streaklines. Comparisons are made with respect to mean center line velocities, drag coefficients, Strouhal number and streakline patterns. Degeneration of naturally occurring Kármán vortex street into a twin eddy pattern is noticed in the Reynolds number (Re) range of 41‐200, under buoyancy aided convection. On the contrary, buoyancy opposed convection could trigger vortex shedding even at a low Re range of 20‐40, where only twin eddies are found in the natural wake. Temporal evolution of unsteady eddy patterns is visualized by means of numerical particle release (NPR). Zones of vortex shedding and twin vortices are demarcated on a plot of Richardson number against Strouhal number. Root mean square (RMS) lift coefficients (C_L,RMS) and average drag coefficient (\overline C_d) are obtained as a function of Richardson number (Ri).

This paper aims to identify, examine, and present an empirical research design of behavioral finance of potential investors during Covid-19.

A well-structured questionnaire was designed; a survey was conducted among potential investors using convenience sampling, and 200 valid responses were collected. The research work uses multiple regression and discriminant function analysis to evaluate the influence of cognitive factors on the financial decision-making of investors.

Recency and familiarity bias are proven to have the highest significant impact on the financial decisions of investors followed by confirmation bias. Overconfidence bias had a negligible effect on the decision-making process of the respondents and found insignificant.

Covid-19 is a temporary phase that may lead to changes in financial behavior and investors’ decisions in the near future.

The paper will help academicians, scholars, analysts, practitioners, policymakers and firms dealing with capital markets to execute their job responsibilities with respect to the cognitive bias in terms of taking financial decisions.

The present investigation attempts to fill the gap in the literature on the intended topic because it is evident from literature on the chosen subject that no study has been undertaken to evaluate the impact of cognitive biases on financial behavior of investors during Covid-19.

Today, amid a global pandemic, the world is changing rapidly. This bought a sense of urgency to adopt this change for the sustainability of both individual and corporate existence. The name given to the future world on the brink of this change and transformation is VUCA (Volatility, Uncertainty, Complexity and Ambiguity). COVID-19 pandemic exposed leadership teams to novel challenges that required many changes to their practices. This has been the most volatile, uncertain, complex, and ambiguous (VUCA) times in healthcare. VUCA software technologies that connect different geographies of the world over the Internet have provided institutions with standardization, harmonization, and acceleration. Understanding the VUCA world, adapting to it, focusing on the opportunities rather than the challenges it brings are the basis of sustainability. In order to increase or maintain the level of development of the countries, it is possible with the health institutions to provide a quality service and the development of standardization based on the VUCA approach. This global pandemic has clearly affected healthcare systems and workers throughout the world, with many worse affected than others. This chapter aimed to give information about the importance of why health managers should provide services based on the VUCA approach.

The purpose of this paper is to investigate the effect of narrow gap on the fluid flow and heat transfer through an eccentric annular region is numerically. Flow through an eccentric annular geometry is a model problem of practical interest.

The approach involves standard finite volume-based SIMPLE scheme. The numerical simulations cover the practically relevant Reynolds number range of 104-106.

In the narrow gap region, temperature shoot up was observed due to flow maldistribution with an attendant reduction in the heat removal from the wall surfaces. CFD analysis is presented with the aid of, streamlines, isotherms, axial velocity contours, etc. The engineering parameters of interest such as, Nusselt number, wall shear stress, etc., is presented to study the effect of eccentricity and radius ratio.

The present investigation is a simplified model for the rod bundle heat transfer studies. However, the detailed study of sectorial mass flux distribution is a useful precursor to the thermal hydraulics of rod bundles.

For nuclear reactor fuel rods, the effect of eccentricity is going to be detrimental and might lead to the condition of critical heat flux. A thorough sub-channel analysis is very useful.

Nuclear safety standards require answers to a wide a range of what-if type hypothetical scenarios to enable preparedness. This study is a highly simplified model and a first step in that direction.

The narrow gap region has been systematically investigated for the first time. A detailed sectorial analysis reveals that, flow maldistribution and the attendant temperature shoot up in the narrow gap region is detrimental to the safe operation.

The future will see a new revolution in both industry and society in Industry 5.0. Human–robot collaboration and robotic management will be critical components of Industry 5.0. In this revolution, humans and robots will collaborate to improve process efficiency by utilizing human intelligence and innovation. Industry 5.0 creates a powerful framework for modern digital smart factories and manufacturing technologies through complex systems, and it is constructed to interact with powerful computing power, to solve complex problems more efficiently and with less human intervention in this Volatile, Uncertain, Complex, Ambiguous, Radicality, and Rapidity (VUCA-RR) world. To overcome VUCA-RR world, Industry 5.0 involves a combination of human and robotic systems for sustainable development. Managers, practitioners, researchers, and educators are scrambling to understand and implement the method as well as to find best practices toward Industry 5.0. This chapter will draw attention to research and practice topics in the VUCA-RR and business agility development methodology in perspective of Industry 5.0.

The world is changing fast and pace of changes that are being observed since start of the twenty-first century have never been observed before. Due to such changes and their impact, world is described in terms of Volatile, Uncertain, Complex and Ambiguous (VUCA). The trend of industry 4.0 is also said to be an another contributing factor into the VUCA environment. The VUCA creates a lot of challenges for organization from the perspective of management and leadership. Both business and leadership agility are needed more than VUCA as the VUCA world is becoming old. Therefore, the purpose of this research is to review the literature and to summarize the understanding with regard to managing VUCA-RR world in an era of Industry 4.0. Since the advent of term VUCA, many researchers have provided theoretical model and framework to guide managers regarding to their action and strategies. But, current research postulates based upon the literature that agile management’s tools and techniques are highly effective in managing the situation of VUCA-RR in the era of Industry 4.0. The research concludes that Industry 4.0 together with VUCA-RR and indecently possess to change management challenges to organizations. The organization can be in better position to manage change management challenges posed by Industry 4.0 by implementing the agile management. The Industry 4.0 will latter compliment to agile management tools and techniques which will make any organization to become a better equipped to face the VUCA-RR world. The research has also concluded that agile management powered by Industry 4.0 enabling technologies presents enormous opportunity in the form of VUCA 2.0 (Vision, Understanding, Courage, Adoptability, Rapidity and Radicality) that can be used to square off the effect of VUCA-RR world.