The solar radiations are absorbed in the form of heat energy by using the solar centering systems in solar collectors, this energy is then transmitted to nanofluid. This study concerns the production of entropy in a Maxwell nanofluid passed over an infinite horizontal surface. Then the non-linear stretching of the surface causes a flow in parabolic trough solar collector (PTSC). The similarity transformations are employed to transmute the system of PDEs into a system of solvable ODEs provided with the boundary conditions. Eventually, the classical Keller box scheme is applied to find the numerical solutions of transmutes ODEs. The analysis of two distinct nanofluids including copper-engine oil (Cu-EO) and zirconium dioxide-engine oil ZrO₂-EO is taken into account and the results for both of them are discussed. The extracted results demonstrate a decline in Nusselt number with growing permeable media parameter and augmentation for increasing values of skin friction coefficient. A recent study is presented to provide information related to the enhancement of heat collector in the PTSC with Maxwell nanofluid. The minimal level of efficiency of Cu-EO over ZrO₂-EO is 7.1% and the maximum level is up to 18.7%.

In this article, thermal performance of engine oil in the presence of both single and multiple wall carbon nanotubes (SWCNTs and MWCNTs) between two concentric cylinders is presented. Flow is driven with oscillatory pressure gradient and magneto-hydrodynamics (MHDs) effects are also introduced to control the random motion of the nanoparticles. Arrived broad, it is perceived that the inclusion of nanoparticles increases the thermal conductivity of working fluid significantly for both turbulent and laminar regimes. Fundamental momentum and energy equations are based upon partial differential equations (PDEs) that contain thermos-physical properties of both SWCNTs and MWCNTs. The solution has been evaluated for each mixture, namely: SWCNT-engine oil and MWCNT-engine oil. Results are determined for each velocity, temperature, pressure and stress gradient. Graphical results for the numerical values of the emerging parameters, namely: Hartmann number (M), the solid volume fraction of the nanoparticles (ϕ), Reynolds number (Reω), and the pulsation parameter based on the periodic pressure gradient are analyzed for pressure difference, frictional forces, velocity profile, temperature profile, crux, streamlines and vorticity phenomena. In addition, the assets of various parameters on the flow quantities of observation are investigated

The objective of the present article is to investigate an incompressible micropolar Prandtl fluid flowing over a porous stretching sheet with the inclusion of effects like exponential temperature-dependent heat source, higher-order chemical reaction viscous dissipation, nonlinear thermal radiation, and multiple convective surface boundary conditions. The nonlinear partial differential equations (PDEs) for momentum, energy, micro-rotation, and concentration are discussed. These PDEs are converted into ordinary differential equations (ODEs) by utilizing suitable variables and then tackled with the utilization of the nonlinear shooting method. For the numerical assessment of upcoming results comparison with already existing literature has been taken. It is canvassed that by augmenting the microrotation parameter, a boost in the angular velocity profile is seen. Moreover, The higher order of reactivity upsurges the heat transmission rate, whilst the mass convection enhances the concentration size. This gives the current model potency as a potential application in clean engine lubricants and coolant industrial liquids under the same constraints.

Solar energy is the major source of heat energy from the sun having immense utilization in technologies like photovoltaic cells, solar energy plates, solar street lights, solar water pumping, and so on. How to maximize the heat energy which is later on used as electrical energy for many purposes in solar aircraft is the hot topic of research in this decade. The current paper is about the study of entropy generation analysis and hybrid nano-solid particles impact on parabolic trough surface collector (PTSC) located inside the solar aircraft wings. homo/heterogeneous reactions have been taken. Non-Newtonian Reiner-Philippoff model along with porous medium and Darcy-Forchheimer effects have been taken into account for the present study. The heat transfer performance of the solar aircraft wings has been enhanced with the inclusion of effects like hybrid nanoparticles, thermal radiations, variable thermal conductivity, and viscous dissipation. By utilizing the proper conversions the demonstrated partial-differential equations are renovated into ordinary-differential formulas and tackled numerically with the utilization of well established numerical scheme termed as Keller-Box method. The impact of dimensionless sundry parameters on velocity, shear stress, temperature, homo/heterogeneous as well as surface drag and heat transfer rates are sketched through tables and figures. A positive variation in thermal radiation, thermal conductivity, and viscous dissipation effects enhances the heat transfer rate inside the solar aircraft wings.

In this article, the motion of a non-Newtonian tangent hyperbolic nanofluid past a stretching sheet is analyzed. Nanofluid is comprised of thermophoresis and Brownian motion effects. Magnetic field is implemented in vertical direction under the assumption of low magnetic Reynolds number. The phenomenon of heat transfer has been examined subject to the viscous dissipation and Joule heating whereas the mass transfer has been analyzed under the effect of chemical reaction. The partial differential equations (PDEs) governing the flow, heat and mass transport are re-framed in the form ordinary differential equations (ODEs) by means of the similarity solutions. A numerical procedure known as the Keller-box method has been implemented to obtain the solutions for the accomplished ODEs. The effects of the variations of different involved parameters on fluid temperature, velocity and concentration distributions are disclosed through graphs and analyzed in detail. The features of skin friction, heat and mass transfer coefficient are tabulated and graphed in order to perceive the flow, heat and mass transport processes. It is noticed that an increment in the Weissenberg number results in a reduction in the velocity field.