Thermal performance of Oldroyd-B hybrid nanofluid in solar energy-based water pumping systems and entropy generation minimization

The growing need for reliable energy supply to enhance productivity in industrial and residential sectors underscores the importance of conserving solar energy. This can be achieved through measures such as optimizing solar collector coatings and optical heat processes. The environmental risks posed by fossil fuels, like coal and diesel, for electricity generation, further highlight the urgency of seeking alternative solutions. Solar energy has emerged as a highly promising option, capturing global attention for its potential to improve productivity and sustainability. The study focuses on examining aluminum alloy-titanium alloy/ethylene glycol hybrid nanofluid in the flow of non-Newtonian Oldroyd-B through a parabolic trough surface collector located in the solar water pumps (SWP). The Galerkin weighted residual method was utilized to solve the group of equations that describe momentum, energy, and entropy generation. The findings show that the hybrid nanofluid leads to better thermal radiative performance compared to the ordinary nanofluid. Therefore, the implications of these findings are substantial, particularly in the fields of thermal engineering and renewable energy. By offering insights into the efficient utilization of solar energy in water pumping systems and the reduction of entropy generation, this research has the potential to drive innovations that enhance the sustainability and performance of such systems. © 2023 The Author(s

Improving agricultural efficiency with solar-powered tractors and magnetohydrodynamic entropy generation in copper–silver nanofluid flow

This study examines the impact of solar-powered tractor on agricultural productivity and energy efficiency. The implementation of solar energy in tractors has the potential to reduce dependence on non-renewable energy sources, minimize carbon emissions, and promote sustainable farming practices. This research investigates the reduction of energy consumption and enhancement of productivity by evaluating magnetohydrodynamic (MHD) entropy production through the flow of nanofluids containing copper-engine oil (Cu-EO) and silver-engine oil (Ag-EO). The study also evaluates the effectiveness of thermal transport in solar-powered tractors through several properties such as solar thermal radiation, viscous dissipation, slippery velocity, and porous media. The investigation analyzed the thermodynamics of entropy generation in a non-Newtonian Williamson nanofluid, with the aim of assessing its energy equilibrium and the effects of diverse physical parameters. In order to enable numerical investigation, similarity variables were implemented to transform partial differential equations into ordinary differential equations, and the Chebyshev collocation spectral method was applied to solve the governing equations. It has been revealed that the Williamson nanofluid have a smoother flow compared to the mixture fluid. Furthermore, Williamson-nanofluid demonstrate superior thermal conductivity and heat transfer characteristics compared to the base fluid, making them appropriate for utilization in cooling systems and heat exchangers in various industries. The boundary layer exhibits the maximum temperature while employing lamina-shaped particles, whilst the lowest temperature is shown when utilizing spherical-shaped nanoparticles. The Ag-EO nanofluid an efficiency rate of approximately 2.64 % with a minimum efficiency rate of 3.22 %. The findings will help develop eco-friendly agricultural methods that promote economic development while mitigating harm to the environment

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

Abstract 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%

Magnetoconvection around an elliptic cylinder placed in a lid-driven square enclosure subjected to internal heat generation or absorption

The impacts of MHD and heat generation/absorption on lid-driven convective fluid flow occasioned by a lid-driven square enclosure housing an elliptic cylinder have been investigated numerically. The elliptic cylinder and the horizontal enclosure boundaries were insulated and the left vertical lid-driven wall was experienced at a fixed hot temperature, and the right wall was exposed to a fixed cold temperature. COMSOL Multiphysics 5.6 software was used to resolve the nondimensional equations governing flow physics. A set of parameters, such as Hartmann number ( 0≤≤50 ), Reynolds number ( 102≤≤103 ), Grashof number ( 102≤≤105 ), heat generation-absorption parameter ( −3≤≤3 ), and elliptical cylinder aspect ratio (AR) ( 1.0≤≤3.0 ) have been investigated. The current study discovered that for low Reynolds number, the adiabatic cylinder AR of 2.0 provided the optimum heat transfer enhancement for the model investigated, also the impact of cylinder size diminishes beyond Gr = 104. But for high Reynolds (Re = 1000), the size of the cylinder with AR = 3.0 offered the highest heat transfer augmentation. The clockwise flow circulation reduces because of an increase in AR, which hinders the flow circulation. In addition, heat absorption supports heat transfer augmentation while heat generation can suppress heat transfer improvement

Effects of Geometric Ratios on Heat Transfer in Heated Cylinders: Modelling and Simulation

The application of fluid and heat transfer in electronic and nuclear technology is gaining popularity, particularly in equipment's life span and risk management.  However, further study is required for applications involving rectangular cylinders placed inside a square cavity.  This study investigates the effects of height ratio  and width ratio  for Prandtl number  on natural convective heat transfer and the flow field around the annulus of a square domain fitted internally with a heated rectangular cylinder.  The square enclosure and the inner rectangular cylinder walls were respectively maintained at cold and hot isothermal conditions. COMSOL Multiphysics (Version 5.6) software was adopted to implement the governing equations and boundary conditions. The results are presented in the form of streamlines, isothermal contours, and Nusselt number (Nu). The study reveals that the combined average Nu of the rectangular cylinder walls improves with    and Rayleigh number (Ra). The maximum Nu occurred at  and ; however, height variation at peak average Nu was 37.7% greater than width variation at peak average Nu.  This study finds applications in the cooling of electronic chips and aerospace engines

Implication of electromagnetohydrodynamic and heat transfer analysis in nanomaterial flow over a stretched surface: Applications in solar energy

The limited availability of non-renewable energy resources, the need to protect ecosystems, and financial considerations create a powerful driving force for studying renewable energy and improving thermal energy systems. The utilization of solar radiation and nanofluids containing polyvinyl alcohol–water-based fluids with copper nanoparticles offers an opportunity to improve the efficiency of sustainable solar heating systems. Owing to its usage, this research examines the electromagnetohydrodynamic and thermal transfer of Jeffrey nanofluid flow over a stretchable surface by employing the influence of gyrotactic microorganisms on this flow. Additionally, the current research focused on creating an advanced numerical model that accurately exemplifies the flow and thermal properties of a parabolic trough solar collector (PTSC) installed on a solar plate to generate a continuous energy source. The unique aspect of our research lies in the integrated approach, combining EMHD, nanofluid flow, and stretchable surface technology to investigate the thermal performance of the coating. This innovative combination opens up new possibilities for efficient thermal management in solar energy applications. The effectiveness of thermal transport in PTSC is evaluated by investigating several factors such as the electric field parameter, solar radiation, exponential heat source, bioconvection Rayleigh, and diffusion parameter. This research utilizes invariant transformations to simplify partial differential equations into ordinary differential equations. These equations are then solved using the wavelets and the Chebyshev wavelets scheme (CWS) with the help of MATHEMATICA 11.3 software. The research outcomes revealed that an increase in the solar thermal radiation, and electric field parameters leads to a higher temperature distribution in concentrated solar power. Therefore, this research aims to improve industrial performance by increasing the efficiency of thermal power generation systems