A novel multi-objective optimization scheme is implemented to enhance the heat transfer characteristics and to reduce pressure drop of heat exchanger in this article. The heat transfer efficiency and pressure drop of the finned heat exchanger are considered as the optimal objective function through the fine-tuning of the heat exchanger’s fin spacing and fin angle. Numerical simulations of the prototype heat exchanger well agree with the experimental findings. The fin spacing and fin angles of the heat exchanger are manipulated as the optimization variables to attain the maximum Nusselt number and the minimum pressure drop. The nonlinear fitting of the data is performed using an Artificial Neural Network (ANN) to obtain the establishment of two predictive models. The models are optimized using a multi-objective Non-dominated Sorting Genetic Algorithm-II (NSGA-II), ultimately yielding a Pareto frontier curve. Two excellent optimization schemes can be obtained for heat exchanger. The Nusselt number of the optimized model rises as much as 4% when the pressure drop is almost consistent with the heat transfer of the original heat exchanger. The pressure drop of the optimized model reduces as much as 9% when the Nusselt number is well consistent with the drag force of the original heat exchanger. The energy efficiency is effectively improved by the optimization models of these two types of heat exchangers and the energy-saving goals are achieved through multi-objective optimization using NSGA-II.

Nowadays, advancements in an engine performance and fuel effectiveness entrust profoundly on the nanotechnology. This modernistic approach minifies friction in engines and enhances lubrication efficiency by inserting the nanoparticles in the base fluid engine-oil. In this study, the Brinkman-type radiative engine-oil based MHD heat consuming Molybdenum-disulfide (MoS2) nanofluid conveyance over the rotating plate in porous environs was investigated. The viscous dissipation and Hall impacts are also designed in the model. The nanofluid flow’s controlling nonlinear dimensional partial differential system of equations are translated by using desirable scaling variables to nonlinear dimensionless partial differential system of equations and are thus numerically solved with finite difference method. The MATLAB software has been utilized to give numerical results of momentum and thermal fields for sundry pertinent parameters and these results are depicted graphically. Computed results of Nusselt number and shear-stresses are recorded in the tables. It was evaluated that an intensifying viscous dissipation, nanoparticle’s volume fraction and radiation effects caused to raise the fluid temperature but Prandtl number and heat consumption have revealed opposite impact. An uprising Brinkman parameter, nanoparticle volume fraction and magnetic field lessen both velocity components, whereas viscous dissipation, Hall and radiation effects heighten both velocity components. The impact of rotation restricts the primary velocity and uprises the secondary velocity. Remarkably, the heat transfer rate improved to 5.16% by dissolving 4% of nanoparticles. The rate of primary shear-stress decreased to 3.4% and the rate of secondary shear-stress enhanced to 12.9% by adding up to 4% of nanoparticles. Further, to assure the validity and correctness, the persisted results are compared with published work and evidenced an excellent accord.

The present work addresses a numerical approach to the fully developed magnetohydrodynamic mixed convection of a viscous, incompressible, electrically conducted fluid, with the radiation parameter in the vertical micro-porous channel filled with porous medium and thermal nonequilibrium conditions being considered. Governing differential equations are solved numerically by using spectral collocation techniques. The aim of this study is to understand the effect of the inter-phase heat transfer coefficient ( H ) , porosity-scaled thermal conductivity ratio γ , radiation parameter R d , and Darcy number Da on the velocity, magnetic field, and heat transfer rate Nu profile. The present study revealed that the magnitude of flow was reduced for the higher value of R d for all three cases ( ζ = 1 , ζ − 0 , ζ = − 1 ) . The Darcy number (Da) reduces the velocity as well as the magnetic field. The velocity profile for ζ = 1 (when both walls are heated) decreases as the inter-phase heat transfer coefficient H increases, while for the other two cases, the reverse effect has been observed. The present study also revealed that there exists a threshold value H 0 of H for ζ = 1 and ζ = 0 where the heat transfer rate N u becomes the decreasing function of H in the interval [ 0 , H 0 ] when radiation parameter R d increases from 1 to 5. Overall, the inter-phase heat transfer coefficient H makes the flow profile smooth (stabilizes the flow) and recovers the system to equilibrium.

This research analyzes the application of nanofluid consisting of Co-H2O to enhance the heat transmission of mixed convection inside a lid-driven porous T-shaped enclosure. For greater thermal contact and heat transfer, copper foam with 40 PPI pore density and 90% porosity is used in this research. Furthermore, the Darcy-Brinkman model generates nanofluid-saturated porous medium equations. The governing equations with proper boundary are solved by using Galerkin weighted residuals of Finite Element Method (FEM). The outcomes are acquired for the average Nusselt number (Nuave ), the solid volume fraction, δ (0.01-0.05), the Reynolds number, Re (50 – 200), the Darcy number, Da (10−5–10−2), the Richardson number, Ri (0.1–10). the unsteady parameter, τ (0.1–1.0), which are the prevailing parameters in this investigation. The graphical results of thermal fields and flow fields at the heated surface of the circumference include the average Nusselt number, streamlines and isotherms. It has been found that Da and Re have a momentous influence on the isotherms and streamlines observed in the enclosure. The results demonstrate that the heat transfer rate is greatly affected by Da, Re and δ. The Nusselt number is examined as a function of the base fluid (water, kerosene, and engine oil) and the volume percent of nanoparticles (Co, Ag, Al2O3, and TiO2). It has been found that increasing the Reynolds number from 50 to 200 at non-dimensional time τ = 0.9 , the average heat transfer rate increased by 75%. It is highlighted that the heat transfer rate for the Co-H2O nanofluid is higher (around 206% at τ = 0.1 ) than the other eight types of considered nanofluids. Moreover, it has been found that water-based nanofluids have a significant higher heat transmission rate than kerosene-based nanofluids.

Hyperthermia has been attracting great attention, research resources and clinical translation efforts as a cancer treatment. Metallic nanoparticles can enhance heat deposition in tumors when subjected to external energy sources like lasers. However, challenges remain in accurately estimating state variables, such as the temperature and heat sources, during treatments. This study presents a combined Physics-Informed Neural Network (PINN) and particle filter approach for state estimation in a model, representing a sample of a nanofluid heated by a near-infrared diode laser. The PINN is trained to solve the heat transfer model and serve as the state evolution model in the particle filter. Synthetic and actual temperature measurements from heating experiments involving a nanofluid of palladium-cerium oxide nanoparticles are used in the solution of the state estimation problem. Verification tests show that the particle filter can robustly estimate states with 850 particles in few seconds of computational time, due to the efficient PINN predictions. Overall, the combined PINN - particle filter approach demonstrates potential for solving state estimation problems in complex engineering systems, such as in cancer thermotherapy.

Today, it is more necessary than ever to move toward optimizing energy consumption and providing sustainable energy. In addition to this, the aspects of optimizing energy consumption in the construction, design, and operation of equipment are of particular importance. Effect of the spiral with short lengths and regular distances with hybrid nanofluids on the heat transfer of turbulent flow and compared performance to the typical state is limit studied. In this regard, a numerical study was conducted to investigate the effects of simultaneous use of spiral and three types of hybrid nanofluid Tio2-Zno, Zno-Al2O3, and Al2O3-TiO2 with ϕ = 0.1% on flow and heat transfer characteristics for different spiral diameter ratios. In the next step, short spirals are used with Al2o3-Tio2 nanofluid with ϕ = 0.1, 0.3, and 0.5. The numerical solution is done using Ansys-Fluent software in three dimensions in a range of Reynolds numbers of 5000–28,000. The analysis shows that the spiral with d/D = 0.05 with Al2O3-TiO2 nanofluid creates maximum thermal performance. The highest Nusselt number is obtained with N = 4 and ϕ = 0.5% at Re = 27000. In the whole study, the changes of Nu/Nus, f/fs, and η are 1.18–2.03, 2.47–5.093, and 0.82–1.348, respectively. Short spirals with regular intervals reduced the friction coefficient, and the thermal performance coefficient improved. This issue is useful in the cost management and energy consumption in industries.

The flow dynamics of an obliquely impinging nanofluid toward a rotating disk holds significance in many industrial processes like mixing tanks, stir-welding, turbo-machinery, and combustion chambers of jet engines. The presence of a phase-changing material emanates a melting heat phenomenon around the solid surfaces in these applications. Motivated by this, the current study investigates the flow characteristics of an obliquely stagnating nanofluid flow over a disk in rotating motion. The disk is stretchable in nature and is endowed with melting heat transport. The flow field is controlled by an external magnetic field acting in the transverse direction, while thermal radiation effects are also considered. The governing mathematical model is reduced to its self-similar form with the usage of appropriate similarity transformations and then solved numerically using the in-built bvp5c numerical solver in MATLAB R2023a. The plot variations reveal substantial impacts of the magnetic field on the flow field. The temperature is increased with the radiation parameter.

Numerical simulations for coupled heat and mass transport in a viscoelastic fluid motion created by an elongating cylinder are provided. The Soret effect as well as non-uniform internal heat source/sink effects are being studied. By assuming an electrically conducting medium, the behavior of axial magnetic force and associated Joule heating effect are incorporated together with the Darcy-Forchheimer term. By adopting a similarity solution technique, a self-similar solution is retrieved that contains important parameters. Drag force applied by the second-grade fluid on the cylindrical boundary is assessed and scrutinized under various controlling parameters. Through graphical illustrations, the impact of diffusion terms on the surface cooling rate is investigated. The current work considers flow visualization utilizing streamlines and isotherms for Newtonian and non-Newtonian flow situations through both porous and non-porous media. For the Newtonian fluid case, computed results for the skin friction coefficient and heat transfer rate are consistent with that of the existing literature.

The mixture of silver nanoparticles (Ag) and zinc oxide nanoparticles (ZnO) in terms of the hybrid nanofluid in a circular, and semicircular porous cavity offers enhanced heat transfer performance, making them suitable for various applications such as electronic cooling, thermal management in engines, and heat exchangers. A water-based hybrid nanofluid composition of Ag and ZnO is used for heat transfer (HT) performance applications. The porous cavity is considered for the flow field under the inspiration of an applied magnetic field. The problem of interest is tackled through the control volume finite element method “CVFEM.” The artificial neural network (ANN) is also applied to handle the obtained results in terms of validation, testing, and training. Auto-encoder (AE) performance has been used for the impacts of different emerging factors of Ha and Ra. The interaction of the magnetic field and magnetic nanoparticles in the hybrid nanofluid causes magnetohydrodynamic (MHD) effects like Lorentz force and magnetization. Nanoparticle concentration, magnetic field intensity (Ha), and cavity porosity (Ra) are the parameters that affect the analysis. Varying these parameters allows for the estimation of the effects of the HNF to evaluate the heat transfer optimization. It is observed that ZnO enhances the HT rate by 14% and Ag + ZnO enhances the HT rate by up to 16% using the 5% nanoparticle volume fraction. Increased Rayleigh numbers enhance natural convection (HT) and encourage more energetic flow behavior, resulting in better heat transfer. Enhanced convective heat transfer is a result of Hartmann numbers, strong Lorentz forces, and metallic and oxide nanoparticles.

Effect of aspect ratio on thermal characteristics, including viscous dissipation, in pressure-driven flow of a third-grade fluid through a rectangular channel is considered. The walls of the channel are assumed to be maintained at uniform temperatures (the special case of the same upper and lower wall temperatures is also discussed). Earlier reported studies on heat transfer characteristics of third-grade fluids considered flow through large parallel plates. In actual case, however, flow occurs in channels and the parallel plate approximation results are only applicable near the central core of the channel, where, influence of the lateral walls are less. In view of this, in the present study, effect of the lateral walls are included in the governing equations and the results obtained are realistic from practical considerations. The effect of viscous dissipation is included in the energy conservation equation, and the influence of the aspect ratio is considered in the momentum and energy conservation equations. Momentum and energy conservation equations are formulated and reduced to their dimensionless forms by introducing suitable dimensionless variables and parameters. Entropy generation equation, including aspect ratio effect is deduced. The dimensionless governing equations are solved by applying the least square method (LSM), and the effects of parameters like aspect ratio, Brinkmann number, and non-Newtonian parameter on temperature, wall heat transfer, and velocity are examined. LSM is a semi-analytical technique which possesses a mixed characteristics of analytical and numerical methods and generates very accurate results. The results are validated with the results of least square homotopy perturbation method. It is important to note that heat transfer is reversed (from the upper wall to the surrounding cooling medium) at a distance of nearly 50% from the lateral walls) with rise in Brinkman number. In the region from lateral walls up to this limit (50% from the walls) heat is transferred from the upper wall to the flowing fluid. Results of the study can serve to be useful for design and analysis of heat exchangers in which lubricating oils, polymers flow takes place.