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Purpose This paper aims to present a numerical study that investigates the flow of MgO-Al2O3/water hybrid nanofluid inside a porous elliptical-shaped cavity, in which we aim to examine the performance of this thermal system when exposed to a magnetic field via heat transfer features and entropy generation. Design/methodology/approach The configuration consists of the hybrid nanofluid out layered by a cold ellipse while it surrounds a non-square heated obstacle; the thermal structure is under the influence of a horizontal magnetic field. This problem is implemented in COMSOL multiphysics, which solves the related equations described by the “Darcy-Forchheimer-Brinkman” model through the finite element method. Findings The results illustrated as streamlines, isotherms and average Nusselt number, along with the entropy production, are given as functions of: the volume fraction, and shape factor to assess the behaviour of the properties of the nanoparticles. Darcy number and porosity to designate the impact of the porous features of the enclosure, and finally the strength of the magnetic induction described as Hartmann number. The outcomes show the increased pattern of the thermal and dynamical behaviour of the hybrid nanofluid when augmenting the concentration, shape factor, porosity and Darcy number; however, it also engenders increased formations of irreversibilities in the system that were revealed to enhance with the permeability and the great properties of the nanofluid. Nevertheless, this thermal enhanced pattern is shown to degrade with strong Hartmann values, which also reduced both thermal and viscous entropies. Therefore, it is advised to minimize the magnetic influence to promote better heat exchange. Originality/value The investigation of irreversibilities in nanofluids heat transfer is an important topic of research with practical implications for the design and optimization of heat transfer systems. The study’s findings can help improve the performance and efficiency of these systems, as well as contribute to the development of sustainable energy technologies. The study also offers an intriguing approach that evaluates entropy growth in this unusual configuration with several parameters, which has the potential to transform our understanding of complicated fluid dynamics and thermodynamic processes, and at the end obtain the best thermal configuration possible.

A new model suitable for both asymmetrical and symmetrical tailor rolled blank (TRB) rolling is proposed by the slab method. In the transition zone of TRB, the work roll moves up or down during the rolling process to carry out variable gauge rolling (VGR). The difference of rolling pressure between VGR and conventional rolling is analyzed. The results reveal that the rolling pressure, rolling force, and rolling torques in downward rolling are larger than those in conventional rolling, while in upward rolling phase, they are less than in the conventional rolling. The variance between VGR and conventional rolling is related to the transition zone shape factor and roll radius. A larger transition zone shape factor results in a more significant difference between VGR and conventional rolling. The effect of roll speed ratio on mechanical parameters during the VGR is nearly identical to that observed in conventional rolling. With the increase of roll speed ratio, the thickness ratio of TRB increases. The VGR force calculated using proposed model agrees well with the experimental values, with a maximum error of 9.7%.

Local scour around bridge piers is one of the main causes of bridge failure all over the world. Experimental and hydraulic models were carried out to investigate two types of scour reduction methods around a single cylindrical pier, namely the pier's slots and collars. The efficiency of various types of pier slots and circular collars around the pier's base in reducing scour were studied. A new shape of a conical collar was developed by the authors and examined along with other shapes. The results revealed that collars, in general, have more influence in reducing scour depth than slots made in the front and rear of bridge piers. The sigma-slot acts better than other tested slots, with a reduction in the scour depths of 59.3% and 52.8% at the upstream and downstream of the pier, respectively. On the other hand, the conical collar appeared to be the most effective collar shape in reducing the scour around the bridge pier, with a 61.1% reduction in the scour depth downstream of the pier. A three-dimensional laser scanner was used to capture the bed topography at the end of each experiment and contour maps of the deformed bed were produced. A one-dimensional Hydrologic Engineering Center-River Analysis System model was developed with a single bridge pier to predict the scour depth around the pier in an attempt to introduce new values for the pier nose shape factor, , which describes the tested piers.

This study investigates the peristaltic transport of Al2O3-Cu/ethylene glycol hybrid nanofluid in an asymmetric microchannel under an inclined magnetic field. The analysis incorporates electroosmosis, Hall current, viscous dissipation, thermal radiation, buoyancy forces, nanoparticle shape, and internal heat source effects. The Poisson–Boltzmann equation is linearized using the Debye-Hückel approximation, and the governing flow equations are solved analytically via the Homotopy Perturbation Method (HPM). Results indicate that increasing the Helmholtz-Smoluchowski velocity parameter from 0.1 to 0.5 leads to a 5.729% rise in skin friction at the left wall. Compared to spherical nanoparticles, laminar-shaped nanoparticles improve heat transfer by 13.9% at the right wall. The present study is novel in that it simultaneously addresses these multiphysical effects, providing a comprehensive understanding of hybrid nanofluid peristaltic flow. The findings offer valuable insights for microfluidic devices, coolant systems, and advanced thermal management applications, including a range of heat exchanger systems such as radiators, heating–ventilation units, and micro-electromechanical systems (MEMS).

Purpose The purpose of this paper is to study the natural convection and radiation heat transfer inside Nonagon inclined cavity with variable heated source length, which contains a porous medium saturated with nanofluid in the presence of uniform heat generation or absorption under the effect of uniform magnetic field with variable direction. The shape factor of nano particles is taking account for the model of nanofluid. Design/methodology/approach This study is established in two-dimensional space. The 2D numerical study is effectuated with Comsol Multiphysics based on the on the finite element method. The 2D equation system is exposed on dimensionless form taking into account the boundary conditions. Findings Results obtained show that the convection heat transfer is ameliorated with the augmentation of heated source length. The convection heat transfer is enhanced by increasing Rayleigh, Darcy numbers and the heated source length; however, it is reduced by rising Hartmann number. The presence of radiation parameter lead to improve the convection heat transfer in the presence of both uniform heat generation/absorption. The average Nusselt number reaches a maximum for an inclination of cavity γ = 45° and a minimum for γ = 60°. Both the increase of the shape factor of nano particles and the solid fraction of nano particles improve the convection heat transfer. Originality/value Different studies have been realized to study the heat transfer inside cavity contains porous medium saturated with nanofluid under magnetic field effect. In this work, the Nonagon geometric of cavity studied has never been studied. In addition, the effect of radiation parameter with relation of the shape factor of nanoparticles in the presence of uniform heat generation/absorption on the heat transfer performance have never been investigated. Also, the effect of magnetic field direction with relation of the inclination cavity on heat transfer performance.

The convection analysis of nanofluid flow under the effect of Marangoni convection, provides important insights into thermal control and fluid dynamics. This phenomenon is critical in many applications, including electronic cooling, heat exchangers, solar thermal collectors, and enhancement in oil recovery by improving fluid flow and promoting controlled crystallization during material processing. Inspired by applications mentioned above, the present research focuses on the couple stress nanofluid flow across a stretching surface while accounting the Marangoni convection, magnetic field, nanoparticles shape factors and thermal radiations. Blood based nanofluid, with the considerations of nanoparticles (gold(Au) and iron-oxide(Fe 2 O 3 )) is supposed for the present research. Boundary layer assumptions and conservation laws are utilized to model a governing mathematical system for the assumed problem. The emerging partial differential equations (PDEs) of the supposed problem is transformed to the ordinary differential equations (ODEs) by utilizing the appropriate similarity transformations. The numerical outcomes are generated in MATLAB using the bvp4c (approach is designed to solve boundary value problems) solver. Results indicates that the increasing estimates of Marangoni number leads the enhancement in the velocity profile and temperature shows a declining trend in the considered scenarios. It is also observed that the velocity-distribution diminishes for the increasing values of magnetic parameter. The temperature profile of the studied nanofluid is decreasing when the Prandtl number and couple stress parameter increases. The effects of the emerging dimensionless parameters on skin friction and Nusselt number are also revealed in the tabulated form. Research may substantially improve the design of nanofluid-based systems, drug delivery techniques, renewable energy technologies, materials engineering, and electronic cooling systems.

For the diamond grinding of ceramic silicon nitride balls based on a plane with circular feed under oscillation, some results of experimental study on the effect of the geometric parameters of the grinding process on the precision of their shape and the shape of the worn surface of a diamond wheel were reported. The shape accuracy criteria were the diameter variation and the out-of-roundness profile shape factor for ground balls and the radial slope angle of the working surface profile and the rate of change in this angle for the worn wheel surface shape. This effect was described by adequate linear functions of process parameters from the ratio between the quantities of balls on the circumferences of their location and the eccentricity of the location of a field of ball trajectories from the rotation axis of a diamond wheel under constant overlapping between the wheel rotation axis and the outer circumference, on which the balls were placed. The values of geometric parameters, at which the studied ball grinding scheme was reasonable to apply, were given.

The model of the elliptical cross-section projectile perforating finite-thick metal targets was developed by combining with the shape function of the elliptical cross-section projectile, where the elastic-decay, plastic-decay, cracking three-stage perforation model was employed. Then, experiments of projectile perforating finite-thick aluminum alloy targets were conducted, including two kinds of elliptical cross-section projectiles and one kind of circular cross-section projectile. The striking velocity of the projectile ranged from 230 m/s to 570 m/s, in which the ballistic limit velocity (BLV) was included. The existed and current experimental results were used to validate the model and agreed well with the calculation results. Besides, the perforation performance of elliptical cross-section projectile and circular cross-section projectile was analyzed. The results showed that the two can be regarded as equivalent projectiles when the mass, head length, any cross-sectional area, and length of projectiles were equal. Next, the critical non-dimensional target thickness was clarified under the different striking factors of the projectile. Calculation results showed that the critical non-dimensional target thickness had a linear relation with the striking factor of the projectile. Furthermore, the influences of the head shape factor of elliptical cross-section projectile on perforation characteristics were studied.

PurposeSeveral graphs, streamlines, isotherms and 3D plots are illustrated to enlighten the noteworthy fallouts of the investigation. Embedding flow factors for velocity, induced magnetic field and temperature have been determined using parametric analysis.Design/methodology/approachTernary hybrid nanofluids has outstanding hydrothermal performance compared to classical mono nanofluids and hybrid nanofluids owing to the presence of triple tiny metallic particles. Ternary hybrid nanofluids are considered as most promising candidates in solar energy, heat exchangers, electronics cooling, automotive cooling, nuclear reactors, automobile, aerospace, biomedical devices, food processing etc. In this work, a ternary hybrid nanofluid flow that contains metallic nanoparticles over a wedge under the prevalence of solar radiating heat, induced magnetic field and the shape factor of nanoparticles is considered. A ternary hybrid nanofluid is synthesized by dispersing iron oxide (Fe3O4), silver (Ag) and magnesium oxide (MgO) nanoparticles in a water (H2O) base fluid. By employing similarity transformations, we can convert the governing equations into ordinary differential equations and then solve numerically by using the Runge–Kutta–Fehlberg approach.FindingsThere is no fund for the research work.Social implicationsThis kind of study may be used to improve the performance of solar collectors, solar energy and solar cells.Originality/valueThis investigation unfolds the hydrothermal changes of radiative water-based Fe3O4-Ag-MgO-H2O ternary hybrid nanofluidic transport past a static and moving wedge in the presence of solar radiating heating and induced magnetic fields. The shape factor of nanoparticles has been considered in this study.

To solve the Laplacian problems, we adopt a meshless method with the multiquadric radial basis function (MQ-RBF) as a basis whose center is distributed inside a circle with a fictitious radius. A maximal projection technique is developed to identify the optimal shape factor and fictitious radius by minimizing a merit function. A sample function is interpolated by the MQ-RBF to provide a trial coefficient vector to compute the merit function. We can quickly determine the optimal values of the parameters within a preferred rage using the golden section search algorithm. The novel method provides the optimal values of parameters and, hence, an optimal MQ-RBF; the performance of the method is validated in numerical examples. Moreover, nonharmonic problems are transformed to the Poisson equation endowed with a homogeneous boundary condition; this can overcome the problem of these problems being ill-posed. The optimal MQ-RBF is extremely accurate. We further propose a novel optimal polynomial method to solve the nonharmonic problems, which achieves high precision up to an order of 10−11.