Nanoparticle Volume Concentration Research Articles

Experimental study of specific heat capacity and thermal conductivity of Al2O3-nanotransformer oil

The Al2O3-nanotransformer oil is regarded as one of the most compatible nanofluids that can function well in transformers. The Al2O3-nanofluids are rich in insulation properties, heat resistance and possess high thermal characteristics. The information gathered for this study outlines the contribution made by the Al2O3 nanoparticles in improving the specific heat capacity and thermal conductivity of the base transformer oil (mineral). The volume of the transformer oil reservoir is measured to be 15 L. When conducting the experimental work, a range of flow rates from (0.20, 0.30, 0.40, 0.50 and 0.60 L/min) and temperatures (35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C & 70 °C) have been used. The nanoparticle size used is fixed at 50 nm. It has been demonstrated that the Al2O3-nanoparticles have better thermal properties than pure transformer oil. At 40 and 50 °C, the overall heat transfer coefficient scored 10.2 and 12.1%. When using the thermal conductivity equation, the nanofluids thermal conductivity is seen to increase with the increase in nanoparticle volume concentration. The availability of nanofluids with high specific heat capacity can be viewed as one of the possible solutions that can be used to reduce energy consumption. The greatest value of the Nusselt achieved is 49% at the temperature of 35 °C and a volume concentration of 0.015% vol.

NUMERICAL SOLUTION ON MIXED CONVECTION FLOW OF NANOFLUID AROUND A FINNED ANGULAR SECTOR OF HEAT SINK

The aim of this study is to investigate mixed convection flow of nanofluid around a three-dimensional (3D) finned angular sector of heat sink by means of numerical simulations. The finite-volume method is used to solve the governing equations of mass, momentum, and energy conservation. The Brownian motion of the nanoparticles in the base fluid is explicitly taken into account in the thermal conductivity model (Patel model). A parametric study is carried out to examine the effects of several key parameters on the rate of heat transfer; the angular sector apex angle, the volume fraction of suspended nanoparticles (0 ≤ φ ≤ 0.09), the Richardson number (<i>Ri</i> = <i>Gr/Re</i><sup>2</sup>), and the size of the nanoparticles diameter (5, 20, 60, and 100 nm). It is shown that for a fixed low Richardson number <i>Ri</i>, the rate of heat transfer increases with the volume fraction of the nanoparticles, as forced convection mechanism is dominated. The heat-transfer enhancement is obtained for the nanofluid water/TiO<sub>2</sub> rather than the water/Cu at higher nanoparticles volume concentration and highest Richardson number. Moreover, the Maxwell thermal conductivity model resulted in a maximum enhancement in the case of nanofluid water/TiO<sub>2</sub> than that of water/Cu, whereas the nanofluid water/ Cu gives better heat-transfer enhancement at small particles than that of water/TiO<sub>2</sub>. It is observed too that the nanoparticles' diameter does not have a significant effect on the temperature field.

Thermal and mechanical characterization of polypropylene composite membrane doped with TiO2 nanoparticles

The HVAC (Heating, Ventilating, and Air Conditioning) industry offers many opportunities for membrane-based gas separation technologies. In this study, a hollow polypropylene (poly-P) fibre membrane loaded with nanoparticles was created to dry out the indoor air. The mechanical and thermal stability of polypropylene loaded nanoparticles (TiO2/poly-P) usually improve with increasing titanium concentration. The example of poly-P with a 4% volume concentration of TiO2 nanoparticles in a polypropylene matrix shows the highest improvement in thermal stability. Atomic force and scanning electron microscopy were used to examine the nanocomposites' structure, and the results showed a correlation between the change in the thermal and mechanical characteristics and the change in TiO2/poly-P content. According to AFM investigations, when titanium nanoparticles are added to poly-P, the supramolecular structure is altered and an ordered structure is created. In comparison to 2% TiO2 doped poly-P nanocomposites, films containing 4% TiO2 demonstrated a more effective immediate moisture retention capacity, according to moisture absorption analyses. This study offers a fresh viewpoint for enhancing the poly-P composite membrane's ability to dehumidify the air.

Predictive Ann Modelling of Thermorheological Properties of Iron-Oxide Yield Stress Nanofluid

The intent of the research is to find the dependency of the volume fraction of nanoparticle (φ) and the temperature on the absolute viscosity (μnf) of Fe3O4 nanoparticles in Carbopol polymer gel. Rheological and stability analysis of the solution is identified. A total of 48 viscosity values has been calculated from experiments using two different base fluid concentrations and two different nanofluid concentrations at eight different temperatures. The data gathered are used for the training of an ANN (Artificial Neural Network) to observe results in a predefined range of two input criteria. It uses a feed-forward perceptron ANN with a temperature input, a volume concentration input, and a viscosity output. The topology was established by trial and error, and the two-layer model having ten neurons in the hidden layer that used the tansig function produced the best results. Ten training functions were utilized to analyze the best result for nf prediction, and the trainbr algorithm was found to be the best ANN. Due to the trained ANN, the anticipated value of viscosity is obtained from each temperature and volume concentration combination. The best results were witnessed with trainlm algorithm with an MSE value of 5.92e-4 and a R2 value of 0.9988 for forecasting of viscosity. Nanoparticle volume concentration increases with viscosity, while temperature increases cause viscosity to decrease. As the temperature rises from 15°C to 50°C, the shear stress value drops with a corresponding shear rate. The shear stress value of the associated shear rate decreases as the nanoparticle concentration rises.

Enhancement of Natural Convection Heat Transfer Using Magnetic Nanofluid in a Square Cavity

Researchers in heat transfer are paying close attention to nanofluids because of their potential as high-performance thermal transport media. In light of natural convection's enormous significance, the addition of nanoparticles significantly enhances the thermophysical properties of the nanofluids compared to the base fluid. In this study, numerical work was used to evaluate the influence of CuO nanoparticles on natural convection with the magnetohydrodynamic (MHD) flow in a square cavity. The hollow's left and right vertical walls were maintained at different temperatures, and the top and bottom walls of the cavity were each insulated. This numerical study applied a horizontal magnetic field with uniform strength. Results were obtained for a variety of Hartmann numbers ranging from 0–300, Rayleigh numbers going from 2.76E+8 to 6.89E+8, and solid volume fractions ranging from 0 to 1.5%. Results showed that the heat transfer coefficient and Nusselt number values decreased with the increase in the values of the Hartmann number, except for the heat transfer coefficients at Ha=100 and 150 were larger than the heat transfer coefficients at Ha= 0. The maximum heat transfer coefficient enhancement was 40.8% at 1.5% volume concentration of CuO nanoparticles, Ra= 6.7E+8 and Ha=100 compared to water at Ha=0. The maximum enhancement of the Nusselt number was found to be 28.5% at a 1.5% volume concentration of CuO nanoparticles Ra= 6.7E+8 and Ha=100 compared to water at Ha=0. At a 1.5% volume concentration of CuO nanoparticles, Ra= 6.7E+8 and Ha=100, the increase in the heat transfer coefficient was 56 %, and the rise in the Nusselt number was 43 % compared to water at Ha=100.

Casson-Nano-Magneto Hydrodynamics Boundary Layer Fluid Flow Towards a Stretching Sheet Including the Effects of Cross Diffusion, Velocity and Thermal Wall Slips

In the occurrence of velocity, thermal wall slip, cross-diffusion belongings (thermal diffusion also thermal diffusion), the possessions of Thermophoresis & Brownian action on the magneto hydro dynamic border coating of Casson-nano fluids in the direction of the stretched layer are studied through numerical solutions. The diffusion thermo effect is added to the energy equation, and the thermal diffusion effect is introduced into the concentration equation. Use similar values to convert the basic flow control equations hooked on ordinary standard differential calculations, & then use the Runge-Kutta method to numerically solve them based on these basic equations. The influence of many technical factors can be determined from these basic equations. Using these basic equations, imaging techniques were worn to learn the influence of a variety of technical factors on various flow variables (such as the velocity, temperature, concentration, & concentration sharing of nanoparticles). In addition, the numerical form also shows the quantity related to the flow factor, such as surface friction, Nusselt number & Sherwood number. Finally, the numerical results attained are compared, and they are completely consistent through the published results in the literature. The experimental results show that as the magnetic field and casson fluid parameters are increased, the velocity profiles decrease. With increasing effects of Thermophoresis and Brownian motion, the temperature profiles are increase. As the values of Dufour number increases, the temperature profiles are also increases. An expansion of the Thermophoresis parameter leads to increased nanoparticle volume concentration distribution and the reverse effect is detected in case of Brownian motion effect. With increasing values of the Soret number parameter, the concentration profiles increase.

A Novel Similarity Solution Approach Based Thermal Performance Prediction and Environmental Analysis of Evacuated U-Tube Solar Collector Employing Different Mono/Hybrid Nanofluids

In this article, a novel similarity function-based two-dimensional steady-state model is developed to analyze the thermal performance of an individual evacuated U-tube solar collector (EUTC). Using the developed model, the energy and environment assessments of a EUTC have been carried out employing different water-based mono/hybrid nanofluids as energy exchange fluids (EEF). The influence of nanoparticle volume concentration on energy gain, mass flow rate reduction, and efficacy has been analyzed. The influence of Reynolds number on energy gain is also investigated. The results show that Al2O3+MWCNT (multiwalled carbon nanotube) has high energy gain, whereas MgO has high mass flow reduction compared to water as a base fluid at 2% volume concentration. The efficacy of EUTC has been enhanced using nanoparticles as an additive. Employing Al2O3+MWCNT as EEF, the impact of EEF flow rate, EEF inlet temperature, ambient temperature, and solar intensity on the energy gain and efficacy of EUTC have been analyzed. It is observed that solar intensity and ambient temperature have major and minimum influence on EUTC performance.

Thermal analysis of multi-finned plate employing lattice Boltzmann method based on Taylor-series/least-squares

A comprehensive experimental/numerical investigation is carried for the purpose of heat transfer and hydrodynamic analysis of natural convection within a cavity equipped with active rectangular fins. Numbers of hot and cold fins are fitted at the surface of square cavity which have remarkable effect on the hydrothermal performance of cavity. In this work, some parameters with significant impact on hydrothermal performance are selected to be studied such as value of Rayleigh number (Ra), value of nanoparticle volume concentration (φV) and arrangement of active fins (Ther.Arr A, B, C and D). To reach this purpose, numerical approach and empirical observations are coupled to provide an accurate data. In order to make the standard Lattice Boltzmann Method (LBM) compatible with the non-uniform grid distribution, the Taylor series expansion and least square-based lattice Boltzmann method (TLLBM) is used. Furthermore, firstly, the SiC-EG nanofluid samples are prepared using modern experimental, and then its rheological and thermal properties are measured using modern devices. It is concluded that using of nanofluid and the thermal arrangement of fins, have significant impact on the thermal performance of cavity.

Analysis at cell scale of porosity effect on forced convection with nanofluids in porous structures with Kelvin cells

• The study is provided with Kelvin cell structure for different porosity values. • Pressure and temperature have periodic trends inside the structures. • Highest velocities are recorded at lower porosities between two cells. • Highest temperature differences are detected between outlet and inlet sections. In this paper a numerical investigation in metal porous structures with Kelvin cell model is carried out on water/Al 2 O 3 nanofluids using the single-phase model. The employed foams are characterized by a fixed value of cells per inch (CPI) equal to 10 for porosity ɛ equal to 0.85, 0.90, 0.92, 0.95, 0.97. For porosity of 0.95 structures at 5, 20 and 40 CPI are also analyzed. Three different values of Al 2 O 3 nanoparticle volume concentrations ϕ , equal to 0, 2 and 4% are used. Results are showed and discussed in terms of pressure drop and temperature profiles, velocity and temperature fields. Correlations for the evaluation of permeability K and drag coefficient C F and their values are also shown. Furthermore, dimensionless entropy generation as function of Reynolds number has been evaluated. The results reveal that both the pressure and the temperature have a periodic trend with oscillations that vary both for the geometric aspects and for the properties of the fluids used. The velocity and temperature fields then serve to understand the dynamic and thermal characteristics: the highest velocities are recorded at lower porosities and at the contact zones from between two cells, as well as the highest temperature differences between outlet and inlet sections. The correlations with which permeability and drag coefficient are obtained reveal that they depend only on the foam used and not on the fluid considered. Finally, the trend of the dimensionless entropy generation as a function of the Reynolds number is decreasing and reducing with increasing porosity.

Experimental Investigation of Aluminum Oxide Nanofluid on Closed Loop Pulsating Heat Pipe Performance

This paper discusses the experimental studies performed on a single closed loop pulsating heat pipe (CLPHP) to evaluate its thermal performance. The pulsating heat pipe is brass which has a single closed loop. Aluminium oxide (Al2O3) and deionized (DI) water nanofluid were utilized as working fluids, with different volume concentrations of aluminium oxide nanoparticles of 0.05 %, 0.5 % and 1%. The aluminium oxide particles are mixed with water in the two-step method to produce a stable suspension. Experiments are carried out in the horizontal mode with watt loads of heat inputs ranging from 10 w to 100 w. The temperature differences between the evaporator and condenser portions, thermal resistance, heat transfer coefficient and thermal conductivity are the parameters used to determine thermal performance. The thermal resistance of aluminium oxide and DI water nanofluid was the lowest, having 48 % less than that of water. The effective thermal conductivity of the heat pipe improves as the concentration of nanoparticles increases. The comparison between experimental results and computational fluid dynamics (CFD) simulation results CLPHP was carried out under the same condition.

Energy and exergy assessment of photovoltaic-thermal system using tungsten trioxide nanofluid: An experimental study

• Serpentine pipes and WO3 nanofluids has proposed to improve PV module efficiency. • Reducing the PV module temperature by 21.4% has enhanced overall efficiency by 29.6%. • Heat transfer coefficient and Nusselt number have enhanced with low pressure drop. • Exergy losses and entropy generation were reduced by 10% and 34.8%, respectively. The temperature rising of the photovoltaic (PV) modules is a major issue leading to a reduction in their conversion efficiency and low output power. Therefore, removing heat from the PV module is necessary to permanently work and improve the electrical power output. Serpentine pipes and a thermal absorber plate has proposed with fluid circulation to reduce the PV cell temperature and improve their efficiency. The current work experimentally investigates the effect of using tungsten trioxide (WO 3 ) nanofluids on the PVT system's energy and exergy efficiency at different volume concentrations of 0. 5 vol%, 0. 75 vol%, and 1 vol%. The results indicated an increment in the electrical power output by 11.15 W due to reducing the PV temperature by 21.4% and enhancing the PVT overall efficiency by 29.6% compared with the cooling by Deionized (DI) water. Increasing the volume concentration of nanoparticles increased the Reynolds number, and the Nusselt number enhanced the heat transfer coefficient and increased the pressure drop. Improving the thermal properties of the nanofluid has increased the electrical exergy efficiency and lowered the thermal exergy efficiency due to the reduction in thermal exergy quality. Compared to DI water cooling, exergy losses and entropy generation were reduced by 10% and 34.8%, respectively.

BORU YÜZEYİNDEKİ KAPSÜL TİPİ KABARTMANIN VE AL2O3 SU NANOAKIŞKANIN ISI TRANSFERİNE ETKİSİNİN SAYISAL ANALİZİ

This study aims to numerically investigate and evaluate the enhancement of heat transfer by new capsule dimples on tube surfaces for flow of water and Al2O3-water nanofluid with different concentrations, under uniform surface heat flux. The originality of this work lies in combining two passive heat transfer enhancement methods such as geometrical improvements and nanofluids together. Capsule dimples with different depths were considered. Al2O3-water nanofluid was modeled as a single-phase flow based on the mixture properties. The effects of dimple depth and nanoparticle concentrations on Nusselt number, friction factor and performance evaluation criteria (PEC) were studied. Numerical computations were performed using ANSYS Fluent commercial software for 2000 14000 Reynolds number range. It was found that when laminar, transient and fully developed turbulent flow cases are considered, increase in the dimple depth increases the Nusselt number and friction factor for both pure water and Al2O3-water nanofluids cases. Also, the friction factor increases as dimple depth increases. Results show that increase in PEC is more pronounced in the laminar region than in the transition region, it starts to decrease for turbulent flows. For nanofluid, PEC values are considerably higher than pure water cases. The variation of PEC for capsule dimpled tubes are dependent on flow regimes and dimple depths. Increasing the nano particle volume concentration and dimple depth in laminar flows increase the PEC significantly.

On the assessment of the thermal performance of microchannel heat sink with nanofluid

By increasing demands for high thermal performance and energy efficiency, attentions to microchannel heat sinks (MCHSs) as the suitable method for heat flux dissipation from thermal systems have increased significantly. Microchannel heat sinks can be widely employed in electronic devices for higher heat removal rate and to provide best performance and durability for electronic systems. The critical issue associated with MCHSs is their ability for integration of effective thermal performance. In this work, on the assessment of the thermal performance of microchannel heat sink with nanofluid is experimentally examined. The heat removal performance of the pure water and nanofluid through the MCHS is studied. Different important parameters, such as dimensionless wall temperature, pressure drop, mean convection heat transfer coefficient, thermal resistance, and uniformity index, are investigated. The results indicated that the maximum suppression value of the thermal resistance attained by employing the nanofluid is 12.61%. The uniformity index of the heating surface is increased as the Re number increases. More suppression in the wall temperature can be observed as the volume concentration of nanoparticles is increased. By increasing the total flow rate and using the nanofluid, the hot spots on the heating surface are suppressed. Finally, the maximum gain value of the nanofluid for the mean convection heat transfer coefficient is up to 14.43%.

Thermal performance of automobile radiator under the influence of hybrid nanofluid

Hybrid nanofluids contain two or more types of nanoparticles mixed with conventional coolant to enhance the thermophysical properties at atomic level. In this study, CuO/SiO2 nanoparticles are distributed evenly in an ethylene glycol-based coolant and a hybrid nanofluid is formed to investigate the effect of heat transfer and thermophysical properties on automobile engines. The simulation is carried out for various volume concentrations ranging from 0.1% to 0.5%. A significant enhancement is noted in the result as the nanoparticle used exhibits higher thermal conductivity. An enhancement in thermal conductivity is noted to be 6.5% higher than the water/EG coolant. A significant enhancement of 48.24% is noted within Nusselt number and the heat transfer rate. As the volume concentration of nanoparticle is increase from 0.1% to 0.5%, due turbulent nature of flow higher amalgamation of nanoparticle results in better thermal performance of automobile system. A reduction of specific heat is noted at volume concentration of 0.5% is much better as compared to volume concentration of 0.1% nanofluid and water/EG coolant. The superior properties of hybrid nanofluid make it an attractive choice as an automobile coolant as the overall efficiency of automobile increases. The result obtained shows tremendous possibility to improve the performance of automobile and reduce fuel consumption.

Experimental investigation of natural convection Al2O3-MWCNT/water hybrid nanofluids inside a square cavity

ABSTRACT The use of nanofluids for convectional heat transfer has become a spry area of research in recent years with the aim of improving heat transfer efficiency. Hybrid nanofluids have attracted significant attention and are advancing research and industrial applications since they involve employing more than one type of nanoparticle(s) in a base fluid. They enhance heat transfer by combining the chemical and physical properties of several nanoparticles concurrently and providing the properties in a homogeneous state. However, few experimental studies have focused on natural convective heat transfer using hybrid nanofluids. In this study, the natural convection of alumina – multiwalled carbon nanotube/water hybrid nanofluids formulated using a two-step method at a percentage weight ratio of 10:90 Al2O3: MWCNT at various nanoparticles volume concentrations of 0.00, 0.05, 0.10, 0.15, and 0.20 vol% was studied inside a square cavity (AR = 1) with two vertical walls which are isothermal, aimed at the Rayleigh number (Ra) range of 2.81 × 108 to 8.58 × 108. The average Nusselt number (Nuav), heat transfer coefficient (hav ), heat transfer (Qav ), and Rayleigh number (Ra) were considered at varying temperature gradients of 20°C – 50°C. Al2O3-MWCNT/water hybrid nanofluid with 0.10 vol% volume concentration was discovered to have the maximum value for hav,Qav , and Nu av. However, it was also observed that a further increase in the hybrid nanoparticles’ volume concentration led to their deterioration at various temperature gradients. The maximum enhancements of 44%, 49%, and 42% were noted for hav,Qav , and Nuav , respectively, at ∆T = 50 °C, in comparison with the base fluid. Al2O3-MWCNT/water hybrid nanofluids application in a square cavity demonstrated enhanced natural convection. This present study concluded that hybrid nanofluids as heat transfer fluid significantly improved heat transfer performance compared to the base fluid.

Entropy analysis of magnetized ferrofluid over a vertical flat surface with variable heating

This research analyzes the entropy generation in a two-dimensional flow of magnetized ferrofluid with variable wall temperature in the presence of heat generation. The mathematical model is designed to consolidate cylindrical-shaped Fe3O4-nanoparticles in pure water. An implicit finite difference is used to obtain the desired numerical solutions. The effects of nanoparticle volume concentration, magnetic parameter, heat generation, and power index on fluid velocity, temperature, entropy generation, and Bejan number are illustrated graphically. The entropy generation increased when the Brinkmann number increased; however, it decreased when the temperature difference decreased. For the authenticity of the current research, the obtained findings are compared with the previously existing results under certain conditions, and a good coexistence is achieved.

Heat transfer analysis of triple concentric tube heat exchanger using MWCNT/water nanofluids under parallel flow configurations

In this investigation, heat transfer characteristics of Multi-Walled Carbon Nanotubes/water nanofluids are studied experimentally in a triple concentric tube heat exchanger under parallel flow configurations and compared with water. The Multi-Walled Carbon Nanotubes/water nanofluids are formulated for 0.2, 0.4 and 0.6% nanoparticle volume concentrations using a two-step method by adding sodium dodecylbenzene sulfonate surfactant. At 0.6% particle volume concentration, the Nusselt number is found to be 10% higher compared with water at 7500 Reynolds number. In this experimental investigation, it is found that at Reynolds number 9500, the overall heat transfer coefficient is enhanced by 15% and pressure drop enhanced by 15% compared with water at 6500 Reynolds number and friction factor is enhanced by 16% compared with water at 0.6% Multi-Walled Carbon Nanotubes/water nanofluids concentration.

Heat Transfer Enhancement in a Receiver Tube of Solar Collector Using Various Materials and Nanofluids

The solar flux distribution on the Parabolic Trough Collector (PTC) absorber tube is extremely non-uniform, which causes non-uniform temperature distribution outside the absorber tube. Therefore, it generates high thermal stress which causes creep and fatigue damage. This presents a challenge to the efficiency and reliability of parabolic trough receivers. To override this problem, we have to homogenize the heat flux distribution and enhance the heat transfer in the receiver’s absorber tube to improve the performance of the PTC. In this work, 3D thermal and thermal stress analyses of PTC receiver performance were investigated with a combination of Monte Carlo Ray-Trace (MCRT), Computational Fluid Dynamics (CFD) analysis, and thermal stress analysis using the static structural module of ANSYS. At first, we studied the effect of the receiver tube material (aluminium, copper, and stainless steel) on heat transfer. The temperature gradients and the thermal stresses were compared. Second, we studied the effect of the addition of nanoparticles on the working Heat Transfer Fluid (HTF), employing an Al2O3-H2O based nanofluid at various volume concentrations. To improve the thermal performance of the PTC, a nanoparticle volume concentration ratio of 1%–6% is required. The results show that the temperature gradients and thermal stresses of stainless steel are significantly higher than those of aluminium and copper. From the standpoint of thermal stress, copper is recommended as the tube receiver material. Using Al2O3 in water as an HTF increases the average output temperature by 2%, 6%, and 10% under volume concentrations of 0%, 2%, and 6% respectively. The study concluded that the thermal efficiency increases from 3% to 14% for nanoparticle volume fractions ranging from 2% to 6%.

Predicting and optimizing the heat transfer performance of radiator with functionalized graphene nanofluids

AbstractAccurately predicting the heat transfer characteristics of coolants used in thermal management of energy systems like heat exchangers, power electronics, and heating, ventilation, and air conditioning is indispensable in maintaining its operating conditions within safety limits. Apart from safety, factors such as power consumption and operating cost are the most important constraints to be considered in designing an energy‐efficient and cost‐effective cooling solution. In this study, the experimental data available from previous research on the use of functionalized graphene‐based nanofluids in compact heat exchangers such as the automotive radiator is used to optimize the heat transfer performance parameters like Nusselt number of the nanofluid, the friction factor, and effectiveness of the heat exchanger. A supervised machine learning technique like the artificial neural network is used to obtain the objective functions of the response variables in terms of input features such as Reynolds number, Prandtl number, the volume concentration of nanoparticles in the base fluid, number of transfer units, heat capacity, the density of nanofluid, pressure drop and velocity. On the current dataset, it is found that by using the Bayesian regularization training algorithm and tangent sigmoidal activation function in the neural network, the best accuracies in the prediction can be achieved. Well‐known nature‐inspired optimization algorithms like genetic algorithms and simulated annealing are used in optimizing the above‐mentioned response variables. Both algorithms converged to the same values of the objective functions. The optimum values of Nusselt number, effectiveness, and friction factor are 105.65, 0.506, and 0.0038, respectively, for the given composition of the nanofluid and radiator configuration.

Thermal and entropy generation analysis of hybrid nanofluid flow through stretchable rotating system with heat source/sink

ABSTRACT This study presents the thermal-fluid transport and entropy generation of a hybrid nanofluid consisting of titanium oxide(TiO2) and gallic oxide(GO), flowing past a stretchable rotating system with a heat source/sink subjected to nonlinear radiation. The nanofluid transport past the rotating disk embedded in a porous medium is described utilizing a higher-order partial nonlinear coupled differential model simplified into an ordinary nonlinear model utilizing Karman’s transformation. This is analyzed utilizing the fourth fifth-order Runge Kutta Fehlberg method (RKF-45) and validated against other literatures for a simple condition that proves satisfactory. The analysis illustrates the impact of nanoparticle volume concentration on entropy generation. This shows that the increasing volume of nanoparticles concentration increases entropy, with the entropy of the hybrid nanofluid lower in relation to the nanofluid. At volume concentration of nanoparticles reveals an entropy magnitude of 7J/K at the lower disk, as the fluid approaches mid plate entropy steadily drops to 3J/K. Thereafter, the magnitude of entropy – as the nano mixture approaches the upper disk – steadily rises to 8J/K. The effect of nanoparticle volume concentration further depicts an increase in Bejan’s number. The study provides good insight into useful and practical applications, including turbines, power generating systems, and blood centrifuges, among others.