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This study is concerned with developing laminar flow of an incompressible, Newtonian fluid, having constant viscosity, rotating in circular and rectangular ducts that contain a 180° bend. The Reynolds number ranges from 100 to 400, the rotation number from 0 to 0.4, and the Dean number from 66 to 264. Positive and negative rotation modes are considered. The artificial compressibility method is used for the numerical calculations and new boundary conditions are developed for these flows. It is shown that rotation causes the secondary flow to occur in ducts of any geometry, and that the strength of the secondary flow in the bend due to both rotation and curvature decreases as compared to the no rotation case.

The artificial compressibility method is used to analyze internal flows in rotating ducts having strong curvature. This study was concerned with the laminar flow of an incompressible Newtonian fluid having constant viscosity in circular and square ducts with a 908 bend. The emphasis of the present simulation is to determine the effect of rotation and through‐flow rate on the fluid physics and friction characteristics in the straight channel and in the curved geometric regions. The Reynolds numbers ranged from 100 to 790 and the Rossby numbers from 0 to 0.4. Coriolis forces arising from rotation produce a non‐symmetric secondary flow in the bend that increases the loss coefficient as compared with the values for non‐rotation. In addition, the wall friction losses in the straight outlet section are increased, and both effects are directly proportional to the Rossby number.

Computation have been made of the three‐dimensional flow field development, chemical reaction and combustion processes in a typical afterburner system under both isothermal and reacting flow conditions. The calculations are based upon a numerical solution of the time‐averaged transport equations for mass, momentum, turbulence kinetic energy, dissipation rate, enthalpy and species concentrations using a finite‐volume formulation. The physical models include the k—ε turbulence model, the eddy break‐up model, a two‐step reaction model, a droplet vaporization and combustion model and six‐flux radiation model. The mean flow structures are presented in important longitudinal and cross‐sectional planes which show certain striking similarities and contrasting differences for isothermal and reacting flows. The flame stabilizer flow is shown to be dominated by a complex combination of recirculation and vortex patterns. Combustion alters convergence and mixing flow patterns downstream of the flame stabilizer, thus influencing the selection of the fuel injection system. The predicted reacting flow parameters identify a number of design parameters such as fuel injector location, high degree reaction zone, nozzle opening area and the corresponding fuel flow rate.

The paper's aim is to investigate the natural convection flow of an Ostwald‐de Waele type power law non‐Newtonian fluid past an isothermal vertical slotted surface.

The Keller‐Box method is used to solve the governing boundary layer equations for the natural convection flow of an Ostwald‐de Waele type power law non‐Newtonian fluid past an isothermal vertical slotted surface.

As the slip parameter increases, the friction factor increases whereas the heat transfer rate decreases. Owing to increase in the value of the Prandtl number, Pr, there is decrease in the value of the skin‐friction coefficient, and augmentation of heat transfer rate. As the viscosity index n increases, both the friction factor and the heat transfer rate increase.

The analysis is valid for steady, two‐dimensional laminar flow of an Ostwald‐de Waele type power law non‐Newtonian fluid past an isothermal vertical slotted surface. An extension to three‐dimensional flow case is left for future work.

The method is useful to analyze perforated plates and wire netting such as perforated wings in order to reduce the drag by suction of the boundary layer, filtration or air‐conditioning.

The results of this study may be of interest to engineers interested in heat transfer augmentation and drag reduction in heat exchangers.

The study aims to focus on rotation effects on a ribbed channel of gas turbine blades for internal cooling. The combination and interaction between secondary flows generated by angled rib geometry and Coriolis forces in the rotating channel are studied numerically.

A radially outward flow passage as an internal cooling test model with and without ribs is used to perform the investigation. Aspect ratio of the passage is 1:1. Square ribs with e/Dh = 0.1, p/e = 10 and four various rib angles of 90°, 75°, 60° and 45° are configured on both the leading and trailing surfaces along the rotating duct. The study covers a Reynolds number of 10,000 and Rotation number in the range of 0-0.15.

Nusselt numbers in the ribbed duct are 2.5 to 3.5 times those of a smooth square duct, depending on the Rotation number and rib angle. The maximum value is attained for the 45° ribbed surface. The synergy angle between the velocity and temperature gradients is improved by the angled rib secondary flows and Coriolis vortex. The decrease of the synergy angle is 8.9, 13.4, 12.1 and 10.1 per cent for the 90°, 75°, 60° and 45° ribbed channels with rotation, respectively. Secondary flow intensity is increased by rotation in the 90° and 75° ribbed ducts and is decreased in 45° and 60° ribbed cases for which the rib-induced secondary flow dominates.

The primary motivation behind this work is to investigate the possibility of heat transfer enhancement by vortex flow with developing turbulence in the view point of the field synergy principle and secondary flow intensity.

Visco‐elastic fluid flow and heat transfer in a porous medium over a non‐isothermal stretching sheet have been investigated. The flow is influenced by linearly stretching the sheet in the presence of suction, blowing and impermeability of the wall. Thermal conductivity is considered to vary linearly with temperature. The intricate non‐linear problem has been solved numerically by shooting technique with fourth order Runge‐Kutta algorithm after using perturbation method. The zeroth order solutions are obtained analytically in the form of Kummer’s function. An analysis has been carried out for two different cases, namely prescribed surface temperature (PST) and prescribed heat flux (PHF) to get the effect of porosity and visco‐elasticity at various physical situations. The important finding is that the effect of visco‐elasticity and porosity is to increase the wall temperature in case of blowing and to decrease in both the cases of suction and when the stretching sheet is impermeable.

The purpose of this paper is to study natural convective heat transfer and viscoelastic fluid flow in a differentially heated square cavity under the effect of thermal radiation.

The cavity filled with a viscoelastic fluid is heated uniformly from the left wall and cooled from the right side while insulated from horizontal walls. Governing partial differential equations formulated in non-dimensional stream function, vorticity and temperature with corresponding boundary conditions have been solved by finite difference method of second order accuracy. The effects of Rayleigh number (Ra = 1e+3−1e+5), radiation parameter (R_d = 0 − 10), Prandtl number (Pr = 1 − 30) and elastic number (E = 0.0001 − 0.001) on flow patterns, temperature fields, average Nusselt number at hot vertical wall and rate of fluid flow have been studied.

It has been found that a growth of elastic number leads to the heat transfer reduction and convective flow attenuation. The heat conduction is a dominating heat transfer mechanism for high values of radiation parameter.

The originality of this work is to analyze heat transfer and fluid flow of a viscoelastic fluid inside a differentially heated cavity. The results would benefit scientists and engineers to become familiar with the flow and heat behavior of non-Newtonian fluids, and the way to predict the properties of this flow for possibility of using viscoelastic fluids in compact heat exchangers, electronic cooling systems, polymer engineering, etc.

Pulsatile flow of an incompressible, Newtonian fluid through a symmetric bifurcated rigid channel was numerically analysed by solving the three‐dimensional Navier‐Stokes equations. The upstream flow conditions were taken from an experimentally measured human arterial pulse cycle. The bifurcation was symmetrical with a branch angle of 60° and a daughter to mother area ratio of 2.0. The predicted velocity patterns were in qualitative agreement with experimental measurements available in the literature. The effect of unsteadiness on the various flow characteristics was studied. The most drastic effect observed was on the flow reversal regions. There was no flow reversal at the highest inlet Reynolds number in the pulse cycle, whereas in the case of steady flow at the same Reynolds number, the flow reversal region was the largest. The presence of secondary flow was observed at all times during the pulse cycle. Shear stress was calculated along the outer and inner walls and the low and high time averaged shear stress regions correspond to the clinically observed sites of formation of atherosclerotic plaque and lesions.

This article aims to study numerically three dimensional developing incompressible flow and heat transfer in a fixed curved pipe.

A projection algorithm based on the second order finite difference method is used for discretizing governing equations written in the toroidal coordinate system.

The effects of curvature and governing non‐dimensional parameters consisting of Reynolds, Prandtl, and Dean numbers on the flow field, entrance length, and heat transfer are studied in detail. The numerical results indicate that the entrance length depends only on the Reynolds number for the curvature ratios greater than 1/7 and therefore, Dean number is not a pertinent parameter in this range.

For heat transfer analysis, two different thermal boundary conditions, i.e. constant wall temperature and constant heat flux at the wall are implemented. The results are calculated for the Dean numbers in the range of 76‐522 and for the two prandtl numbers of 0.5 and 1.

The results can be used in designing heat exchangers, piping systems, and cooling of gas turbine blades.

The numerical results obtained here concentrate on the detailed investigation of flow and temperature field at the entrance region by a quantitative analysis of hydrodynamic and thermal entrance length. The effects of different thermal boundary conditions and different inlet profiles on the flow and temperature fields are studied in the circular curved pipe for the first time.

Pressure on business to direct their activities responsibly has been increased during the last years to extent their suitability performance in all economic, social and environmental dimensions. This has motivated businesses and researchers to identify ways to implement sustainable and resilient operations. In the era of economic globalisation, small and medium enterprises (SMEs) are recognised as an engine of sustainable economic development in both the developed and developing world. Their competitiveness drives the economy, both nationally and internationally. SMEs have faced challenges in developing, internationalisation and achieving competitive advantage. Purpose of current study is to identify and analyse the sustainability and resiliency (SR) barriers to SME internationalisation and prioritise the practices to overcome the negative influence of barriers. In this regard, first, barriers and innovative practices have been identified through the literature review. Second, the essential barriers will be selected through reduction steps by the intuitionistic fuzzy Delphi (IF-Delphi) method. After computing the weight of barriers through the IF-DEMATEL method, the practices were prioritised using four multiple attribute decision-making (MADM) methods in an IF environment. Finally, the scores were aggregated by correlation coefficient and standard deviation (CCSD) technique. Results present that ‘Lack of economical resources to global exports’ and ‘Complications in acclimatizing export product design’ are the top priority barriers and ‘Knowledge of global market opportunities’ and ‘Networking with business incubator institutions’ have been recognised as the essential SMEs internationalisation practices. This study contributes to creating a more focussed approach towards the growth of SMEs. The study results would be helpful for industry, policymakers and academia.