Numerical investigation of heat transfer and fluid flow characteristics of ternary nanofluids through convergent and divergent channels.

The characteristics of nanomaterials have garnered significant attention in recent research on natural and forced convection. This study focuses on the forced convection characteristics of ternary nanofluids within convergent and divergent channels. The ternary nanofluid comprises titanium oxide (TiO2), zinc oxide (ZnO), and silver suspended in water, which serves as the base fluid. Using COMSOL Multiphysics 6.0, a reliable software for finite element analysis, numerical simulations were conducted for steady and incompressible two-dimensional flow. Reynolds numbers varying from 100 to 800 were employed to investigate forced convection. Additionally, we explored aspect ratios (channel height divided by the height of the convergent or divergent section) of -0.4, -0.2, 0, 0.2, and 0.4. Our findings revealed that only at aspect ratio a = 0.4 did the average outlet temperature increase as the Reynolds number rose, while other aspect ratios exhibited decreasing average temperatures with declining Reynolds numbers. Moreover, as the Reynolds number increased from 100 to 800 and the total volume fraction of the ternary nanofluids ranged from 0.003 to 0.15, there was a significant 100% enhancement in the average Nusselt number. For clarity, this article briefly presents essential information, such as the study's numerical nature, fluid properties (constant-property fluid), and the methodology (COMSOL Multiphysics 6.0, finite element analysis). Key conclusions are highlighted to enable readers to grasp the main outcomes at a glance. These details are also adequately covered in the manuscript to facilitate a comprehensive understanding of the research. The utilization of this emerging phenomenon holds immense potential in various applications, ranging from the development of highly efficient heat exchangers to the optimization of thermal energy systems. This phenomenon can be harnessed in scenarios in which effective cost management in thermal production is a critical consideration.

Squeezed Darcy-Forchheimer Casson nanofluid flow between horizontal plates under the effect of inclined magnetic field.

This article explores the properties of heat and mass transport for MHD Casson nanofluid flow between two horizontal plates by considering the Darcy-Forchheimer medium. The effects of a uniform inclined magnetic field are discussed numerically. A Darcy-Forchheimer medium is considered in the x-direction between two plates. The features of Brownian diffusive motion, porosity, friction, viscous dissipation, chemical reaction, and thermophoresis are also considered. The governing equations of the model are a system of partial differential equations. This system is converted into non-linear ordinary differential equations using suitable similarity functions. The numerical shooting technique is used to solve the attained boundary value problem. This numerical technique is endowed with the Runge-Kutta order four method and the Newton method. Graphs and tables depict different significant effects. It is observed that the effect of a magnetic field is inversely related to the fluid flow. Moreover, the porosity factor (λ) and the magnetic inclination (γ) are inversely related to the surface drag force (Cf) and the Nusselt number (Nu).

Viscoelastic fluid flow over a horizontal flat plate with various boundary slip conditions and suction effects.

This study examines the numerical representation of fluid flow on the Maxwell model in a double-diffusive boundary layer over a horizontal plate. The investigation incorporates slip conditions, encompassing momentum slip, thermal slip, and suction parameters. Moreover, the study includes the inspiration of thermal radiation, heat generation, and mass transfer. The governing partial differential equations (pertaining to momentum, continuity, energy transport, and mass transport) are transformed into ordinary differential equations (ODEs) using appropriate similarity transformations. To solve these equations in conjunction with suitable boundary conditions, the bvp4c inbuilt software is implemented. This is achieved through the shooting approach employed in MATLAB. A comprehensive agreement between the numerical technique and previously published findings demonstrates its efficacy. The outcomes are presented through graphical representations and tables, showcasing various parameters such as momentum slip, temperature slip, local Nusselt number, Sherwood number, and suction parameter. The primary motivation of this research lies in investigating the behaviour of Maxwell fluid flow in the absence of slip conditions. The study of Maxwell fluid flow over a flat plate with the combined effects of suction, thermal slip, and momentum slip conditions has a wide range of practical applications that span multiple industries, contributing to improved designs, efficiency, and understanding of fluid behaviour in various systems. The main aim of this study is to present streamlined results under varying conditions, explicitly investigating the influence of suction effects and slip conditions on the flow.

Maximizing electrical output and reducing heat-related losses in photovoltaic thermal systems with a thorough examination of flow channel integration and nanofluid cooling.

In recent years, global energy demand has surged, emphasizing the need for nations to enhance energy resources. The photovoltaic thermal (PV/T) system, capable of generating electrical energy from sunlight, is a promising renewable energy solution. However, it faces the challenge of overheating, which reduces efficiency. To address this, we introduce a flow channel within the PV/T system, allowing coolant circulation to improve electrical efficiency. Within this study, we explore into the workings of a PV/T system configuration, featuring a polycrystalline silicon panel atop a copper absorber panel. This innovative setup incorporates a rectangular flow channel, enhanced with a centrally positioned rotating circular cylinder, designed to augment flow velocity. This arrangement presents a forced convection scenario, where heat transfer primarily occurs through conduction in the uppermost two layers, while the flow channel beneath experiences forced convection. To capture this complex phenomenon, we accurately address the two-dimensional Navier-Stokes and energy equations, employing simulations conducted via COMSOL 6.0 software, renowned for its utilization of the finite element method. To optimize heat dissipation and efficiency, we introduce a hybrid nanofluid comprised of titanium oxide and silver nanoparticles dispersed in water, circulating through the flow channel. Various critical parameters come under scrutiny, including the Reynolds number, explored across the range of 100-1000, the volume fractions of both nanoparticle types, systematically tested within the range of 0.001-0.05, and the controlled speed of the circular cylinder, maintained within the range of 0.1-0.25 m/s. It was found that incorporating silver nanoparticles as a suspended component is more effective in enhancing PV/T efficiency than the addition of titanium oxide. Additionally, maintaining the volume fraction of titanium oxide between 4 and 5% yields improved efficiency, provided that the cylinder rotates at a higher speed. It was observed that cell efficiency can be regulated by adjusting four parameters, such as the Reynolds number, cylinder rotation speed, and the volume fraction of both nanoparticles.

Enhancing heat transfer in solar-powered ships: a study on hybrid nanofluids with carbon nanotubes and their application in parabolic trough solar collectors with electromagnetic controls.

The aim of this research is to explore the use of solar-powered ships (SPS) as a means to reduce greenhouse gas emissions and fossil fuel dependency in the maritime industry. The study focuses on improving the heat transfer efficiency in SPS by employing hybrid nanofluids (HNF) containing carbon nanotubes (CNTs). Additionally, a novel approach utilizing renewable energy and electromagnetic control is proposed to enhance the performance of SPS. The research implements the non-Newtonian Maxwell type and Cattaneo-Christov heat flux model in parabolic trough solar collectors used for ships. The study conducts theoretical experiments and simulations to evaluate the thermal conductivity and viscosity of the CNT-based HNF. Various properties, including solar thermal radiation, viscous dissipation, slippery velocity, and porous media, are assessed to determine the effectiveness of thermal transport in SPS. The research employs similarity variables to simplify the complex partial differential equations into ordinary differential equations and solves them using the Chebyshev collocation spectral method. The results indicate that the MWCNT-SWCNT/EO hybrid nanofluid significantly improves the thermal conductivity, thereby enhancing heat transfer. The HNF exhibits an efficiency rate of approximately 1.78% with a minimum efficiency rate of 2.26%.

A laminar forced convection via transport of water-copper-aluminum hybrid nanofluid through heated deep and shallow cavity with Corcione model.

The article explores how fluid flows and heat transfers in both deep and shallow cavities when using a nanofluid made of water, copper, and aluminum oxide. The study applies the Corcione model to hybrid nanofluids, which considers viscosity, conductivity, and the size of the nanoparticle, temperature, and Reynolds number. The cavity is connected to a rectangular channel, with the cavity's length being half the total length of the enclosure, and the aspect ratio (cavity height divided by height of the channel) is tested from 1 to 3. The study uses the Navier-Stokes equation and energy equation in two dimensions, along with finite element-based software, COMSOL 5.6, to simulate the combination of fluid flow and heat transmission. The results show a circular distribution of temperature in the cavity, and the average temperature drops as the volume fraction of copper upsurges. However, both the Reynolds number and volume fraction of copper improve the average Nusselt number, which shows how well the fluid transfers heat, along the cavity's middle line. The percentage change in the average Nusselt number decreases as the aspect ratio increases, indicating improved conduction.