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A laminar swirling jet impinging on to an adiabatic solid wall is investigated. The flow field is computed and entropy analysis is carried out for different flow configurations. The numerical scheme employing a control volume approach is introduced when solving the governing equations of flow and energy. In order to examine the effect of the nozzle exit velocity profile and the swirling velocity on the flow field and entropy generation rate, six nozzle exit velocity profiles and four swirl velocities are considered. It is found that the influence of swirl velocity on the flow field is more pronounced as the velocity profile number reduces. In this case, two circulation cells are generated in the flow field. The total entropy generation increases with increasing swirl velocity for low velocity profile numbers. The Merit number improves for low swirling velocity and high velocity profile numbers.

A confined laminar swirling jet is an interesting research topic due to flow and temperature fields generated in and across the jet. In the present study, a confined laminar swirling jet is studied, and flow and temperature fields are simulated numerically using a control volume approach. In order to investigate the influence of the jet exiting (exiting the nozzle and inleting to the control volume) velocity profiles on the flow and heat transfer characteristics, eight different velocity profiles are considered. To identify each velocity profile, a velocity profile number is introduced. Entropy analysis is carried out to determine the total entropy generation due to heat transfer and fluid friction. Merit number is computed for various swirling velocities and velocity profiles. It is found that swirling motion expands the jet in the radial direction and reduces the jet length in the axial direction. This, in turn, reduces the entropy generation rate and improves the Merit number. Increasing velocity profile number enhances the entropy production rate, but improves the Merit number.

To investigate the influence of conical and annular nozzle geometric configurations on the flow structure and heat transfer characteristics near the stagnation point of a flat plate with limited heated area.

The conical and annular conical nozzles were designed such that the exit area of both nozzles is the same and the mass flow rate passing through the nozzles is kept constant for both nozzles. The governing equations of flow and heat transfer are modeled numerically using a control volume approach. The grid independent solutions are secured and the predictions of flow and heat transfer characteristics are compared with the simple pipe flow with the same area and mass flow rate. The Reynolds stress turbulence model is employed to account for the turbulence. A flat plate with a limited heated area is accommodated to resemble the laser heating situations and air is used as assisting gas.

It is found that nozzle exiting velocity profiles differ considerably with changing the nozzle cone angle. Increasing nozzle cone angle enhances the radial flow and extends the stagnation zone away from the plate surface. The impinging jet with a fully developed velocity profile results in enhanced radial acceleration of the flow. Moreover, the flow structure changes considerably for annular conical and conical nozzles. The nozzle exiting velocity profile results in improved heat transfer coefficient at the flat plate surface. However, the achievement of fully developed pipe flow like velocity profile emanating from a nozzle is almost impossible for practical laser applications. Therefore, use of annular conical nozzles facilitates the high cooling rates from the surface during laser heating process

The results are limited with theoretical predictions due to the difficulties arising in experimental studies.

The results can be used in laser machining applications to improve the end product quality. It also enables selection of the appropriate nozzle geometry for a particular machining application.

This paper provides information on the flow and heat transfer characteristics associated with the nozzle geometric configurations and offers practical help for the researchers and scientists working in the laser machining area.

The purpose of this study is to understand the basics of interactions of groundwater and surface water, which is needed for effective management of water resources.

The experimental setup was framed using curved flume and the straight flume, which simulates the model of river and groundwater storage, respectively. The model set up further consists, downstream, central and upstream sections where 14 observation wells, which are arranged at a measured distance from the canal side.

Exit gradient is higher at downstream when the average head differences between canal and river are 31.9 cm and 35.7 cm. Free seepage height is more in the downstream wells than upstream and central wells. At the downstream section, there is a greater chance of instability of the riverbank.

Results will be used for better planning of hydraulic structural design.

Results will help in storing the large water and better irrigation planning for the water acute states and locations.

The originality is own developed physical model and its own first type to understand the basic of interaction and effects.

This paper aims to develop a numerical model of bead spreading architecture of a viscous polymer in fused filament fabrication (FFF) process with different nozzle geometry. This paper also focuses on the manufacturing feasibility of the nozzles and 3D printing of the molten beads using the developed nozzles.

The flow of a highly viscous polymer from a nozzle, the melt expansion in free space and the deposition of the melt on a moving platform are captured using the FLUENT volume of fluid (VOF) method based computational fluid dynamics code. The free surface motion of the material is captured in VOF, which is governed by the hydrodynamics of the two-phase flow. The phases involved in the numerical model are liquid polymer and air. A laminar, non-Newtonian and non-isothermal flow is assumed. Under such assumptions, the spreading characteristic of the polymer is simulated with different nozzle-exit geometries. The governing equations are solved on a regular stationary grid following a transient algorithm, where the boundary between the polymer and the air is tracked by piecewise linear interface construction (PLIC) to reconstruct the free surface. The prototype nozzles were also manufactured, and the deposition of the molten beads on a flatbed was performed using a commercial 3D printer. The deposited bead cross-sections were examined through optical microscopic examination, and the cross-sectional profiles were compared with those obtained in the numerical simulations.

The numerical model successfully predicted the spreading characteristics and the cross-sectional shape of the extruded bead. The cross-sectional shape of the bead varied from elliptical (with circular nozzle) to trapezoidal (with square and star nozzles) where the top and bottom surfaces are significantly flattened (which is desirable to reduce the void spaces in the cross-section). The numerical model yielded a good approximation of the bead cross-section, capturing most of the geometric features of the bead with a reasonable qualitative agreement compared to the experiment. The quantitative comparison of the cross-sectional profiles against experimental observation also indicated a favorable agreement. The significant improvement observed in the bead cross-section with the square and star nozzles is the flattening of the surfaces.

The developed numerical algorithm attempts to address the fundamental challenge of voids and bonding in the FFF process. It presents a new approach to increase the inter-bead bonding and reduce the inter-bead voids in 3D printing of polymers by modifying the bead cross-sectional shape through the modification of nozzle exit-geometry. The change in bead cross-sectional shape from elliptical (circular) to trapezoidal (square and star) cross-section is supposed to increase the contact surface area and inter-bead bonding while in contact with adjacent beads.

From the solution of full Navier—Stokes and energy equations, the development of the flow field and heat transfer characteristics in a radial jet reattachment flow have been analysed. The influence of Reynolds number of re‐attachment length for the case of steady laminar flows has been determined. However, beyond a Reynolds number of 250, the flow field becomes unsteady and has been found to have a periodic nature. This periodic flow has been found to persist up to a Reynolds number of 750. The periodicity has been characterized by the Strouhal number which shows a slight but continuous variation with Reynolds number around a value of 0.12. The point of maximum heat transfer is within the re‐attachment zone in the range of Reynolds numbers studied.

The effects of a co-flow and inlet jet temperature on local entropy generation in turbulent round jets have been studied numerically. The second-order closure turbulence model has been used. The paper aims to discuss these issues.

Numerical results are presented and discussed.

The numerical results for the mean quantities, entrainment of air, mixing efficiency, generation of entropy rate and Merit number are presented and discussed.

The expansion of the jet at low velocity of the co-flow and high inlet jet temperature enhances the heat transfer rate and reduces the irreversibility of the jet.

The purpose of this paper is to numerically investigate the effects of different heating and cooling scenarios on the flow structure in a vertically oriented plane sudden expansion. Four different heating and cooling scenarios are considered. The scenarios include symmetric or asymmetric heating or cooling of the downstream channel walls.

The governing equations are formulated using a stream function‐vorticity approach. Second‐order accurate central differencing is used to discretize all terms, including the nonlinear convection terms in the vorticity transport and energy equations. Numerical test cases are simulated for Reynolds number values up to 200 and Grashof number values up to 400.

Numerical simulations show that symmetric heating results in the reduction and ultimately the elimination of flow separation zones near the channel walls while creating a region of reversed flow in the core. On the other hand, symmetric cooling causes the flow to adopt a wavy structure which significantly enhances heat transfer due to jet impingement effects. Finally, it is shown that asymmetric heating causes the flow to preferentially attach to the high‐temperature wall while asymmetric cooling causes the flow to separate completely from the low‐temperature wall.

The behaviour of fluid flow in a plane sudden expansion under symmetric heating is available in the literature. In the present study, the flow structure under alternative heating and cooling scenarios is investigated for the first time.

The purpose of this paper is to reveal and empirically validate a new typology of company strategic profiles regarding intangible resources.

The study is carried out in three steps. The first stage comes to identify the coordinates of intangibles in which strategic profiles are found. The second stage enables a clusterization of more than 1,600 European companies observed during seven years in the coordinates of intangibles. The last step introduces comparative analysis of these clusters in terms of their performance.

As a result of empirical analysis three strategic profiles regarding intangibles are discovered. Two of these profiles are called intangible-intensive as they demonstrate clear predominance of a particular set of intangibles. The innovative profile is associated with intensive investment in innovation and networking capabilities. The conservative profile puts emphasis on managerial capabilities and development of business process. The non-intangible-intensive profile, that has been called moderate, evenly allocates resources among intangibles keeping them on a low level relative to the intangible-intensive profiles.

This research is useful for practitioners in strategic and knowledge management. It provides insight into common features of company strategies for intangibles as well their impact on short- and long-term performance.

This work contributes to the field of strategic knowledge management by demonstrating a new relevant typology in company behavior regarding intangibles. Moreover, it equips decision makers in companies with a tool to design strategic vision in intangibles.

To 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.

A 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.

The 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.

The number of cooling holes in the computational domain is limited by the speed of the computers used.

The 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.

This 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.