Thermal Radiation Effects Research Articles

IMPACT OF CHEMICAL REACTION ON MHD BOUNDARY LAYER FLOW OF NANOFLUIDS OVER A NONLINEAR STRETCHING SHEET WITH THERMAL RADIATION HAAR WAVELET COLLOCATION METHOD

In this paper, we investigate the effects of chemical reaction and thermal radiation on MHD boundary layer fluid flow of nanofluid moving over a nonlinearly stretching sheet through semi-numerical approach. The nanofluid physical model of the problem comprises with effects of thermophoresis, radiation and chemical reaction parameters. The mathematical model scrutinizes mass, momentum, heat transfer and concentration equations are reduced to couple nonlinear ordinary differential equations over infinite domain using proper similarity variables. Haar wavelet collocation method is used to solve the resulting equations. The obtained results are compared with available numerical findings and are comparable which confirms and verifies the wavelet method. The effects of various non-dimensional parameters on the rate of heat and mass transfer are depicted through tables and graphs. It predicts that, the local Sherwood number increases with increase in the parameters of Brownian motion and thermophoresis. For both temperature and volume fraction profiles decreases due to an increase in the Schmidt number.

An investigation of heat transfer and optimization of entropy in bio-convective flow of Eyring-Powell nanomaterial with gyrotactic microorganisms

Entropy generation in nanofluid flows is a critical parameter that influences the performance, efficiency, and sustainability of thermal systems. Understanding and optimizing entropy creation can lead to noteworthy advancements in numerous engineering applications, from renewable energy systems to industrial processes and biomedical equipments. The purpose of this article is to examine the entropy produced in the bioconvection flow of Eyring-Powell nanomaterial with gyrotactic microorganisms. The mathematical equations representing the flow are modeled considering the flow towards a porous surface of a cylinder. Together with the effects of the governing parameters, the mass and heat transfer components of the problem are discussed. The thermal effects of different natures are used in a new way. Overall, entropy creation is designed with regard to the second law of thermodynamics. Activation energy, chemical reaction, thermal radiation, and internal friction force effects are accounted for the development of the mathematical model. Coupled non-linear dimensional equations have been altered into ordinary differential equations (ODEs) and then treated using the MATLAB Finite Difference Method (FDM). Consequence of diverse sundry parameters on entropy production, thermal field, mass concentration profile, Bejan quantity, and motile density of microorganisms is deliberated via plots. Through tables, engineering quantities are analyzed. According to the findings, the velocity profile rises as the curvature and Eyring-Powell fluid parameters rise, while it falls when the magnetic parameter is enhanced. Additionally, it is noted that as the curvature variable enhances, the rate of heat transfer and skin friction coefficient decays.

Velocity slip and temperature jump effects on entropy generation of MHD second-grade hybrid nanofluid in Jeffery-Hamel flow

PurposeThis paper aims to model and analyze Jeffery Hamel’s channel flow with the magnetohydrodynamics second-grade hybrid nanofluid. Considering the importance of studying the velocity slip and temperature jump in the boundary conditions of the flow, which leads to results close to reality, this paper intends to analyze the mentioned topic in the convergent and divergent channels that have significant applications.Design/methodology/approachThe examination is conducted on a EG-H_2 O <30%–70%> base fluid that contains hybrid nanoparticles (i.e. SWCNT-MWCNT). To ensure comprehensive results, this study also considers the effects of thermal radiation, thermal sink/source, rotating convergent-divergent channels and magnetic fields. Initially, the governing equations are formulated in cylindrical coordinates and then simplified to ordinary differential equations through appropriate transformations. These equations are solved using the Explicit Runge–Kutta numerical method, and the results are compared with previous studies for validation.FindingsAfter the validation, the effect of the governing parameters on the temperature and velocity of the second-grade hybrid nanofluid has been investigated by means of various and comprehensive contours. In the following, the issue of entropy generation and its related graphical results for this problem is presented. The mentioned contours and graphs accurately display the influence of problem parameters, including velocity slip and temperature jump. Besides, when thermal radiation is introduced (Rd = +0.1 and Rd = +0.2), entropy generation in convergent-divergent channels decreases by 7% and 14%, respectively, compared to conditions without thermal radiation (Rd = 0). Conversely, increasing the thermal sink/source from 0 to 4 leads to an 8% increase in entropy generation at Q = 2 and a 17% increase at Q = 4 in both types of channels. The details of the analysis of contours and the entropy generation results are fully mentioned in the body of the paper.Originality/valueThere are many studies on convergent and divergent channels, but this study comprehensively investigates the effects of velocity slip and temperature jump and certainly, this geometry with the specifications presented in this paper has not been explored before. Among the other distinctive features of this paper compared to previous works, the authors can mention the presentation of velocity and temperature results in the form of contours, which makes the physical analysis of the problem simpler.

Flow analysis of water conveying nanomaterials over a rotating surface with thermal radiation

PurposeThe present findings aim to investigate the thermal behavior of water-based nanofluid flow over a rotating surface, focusing on understanding the effects of different types of nanoparticles on thermal efficiency, considering thermal radiation and variable viscosity effects. By considering four distinct nanoparticles – silicon dioxide titanium dioxide, aluminum oxide and molybdenum disulfide – the study aims to provide insights into how nanoparticle addition influences heat production, thermal boundary layer thickness and overall thermal performance.Design/methodology/approachThe study employs computational methods, utilizing the BVP mid-rich algorithm for the solution procedure. The computational approach allows for a detailed investigation of the thermal behavior of nanofluid flows across a rotating surface under varying conditions.FindingsThe study concludes that adding nanoparticles in the base liquid increases heat production in the system, resulting in enhanced thermal boundary layer thickness. The comparative analysis shows that different nanoparticle types exhibit varying effects on thermal efficiency, suggesting that careful selection of nanoparticles can optimize heat transport and thermal management processes. Moreover, there's a noteworthy uptrend in the radial velocity profile concerning the stretching parameter, whereas a converse trend is observed in the thermal profile.Originality/valueThis study contributes original insights by comprehensively investigating the thermal behavior of water-based hybrid nanofluid flow over a rotating surface.

Investigation of heat transfer phenomenon in a complex wavy divergent channel under the effects of thermal radiation, joule heating and electroosmosis

The heat transfer analysis in electro osmotic flow of nanofluid is studied through the complex wavy channel under the consideration of joule heat and thermal radiation effects. The Ellis fluid is considered a base fluid and gold particles are suspended in them. The complex system of equations is converted to dimensionless form with the help of dimensionless transformation and parameters. The concepts of longer wavelength and lower Reynolds number are utilized to simplify the problem and obtain the exact solution of velocity and temperature distribution by using the built-in command DSolve in the mathematical software MATHEMATICA 13.3. The graphs are plotted with the same software to check the effects of various parameters on velocity, temperature, heat transfer rate, and streamlines with the following range of parameters − 5 ≤ U H S ≤ 5 , 0 ≤ β ≤ 5 , 0 ≤ α ≤ 3 , 0 < k ≤ 5 , 0 ≤ ϕ ≤ 0.04 , 20 ≤ P r ≤ 28 , 0 ≤ R n ≤ 5 . The computational results reported that the electroosmotic parameter, Helmholtz-Smoluchowski velocity, and material parameter reduce the velocity in the initial region and enhance the final region of the channel. It is also noted that the velocity profile exhibits increasing and decreasing behavior in the initial and final region respectively with upgrading the values of volumetric concentration of nanoparticles. The heat transfer rate is strongly affected by material parameters α and β , thermal radiation parameter, Prandtl number, and joule heating and these parameters promote the heat transfer rate of the system. The novel research of the current study shows the examination of the heat transfer analysis of blood-gold nanofluid in the presence of an electrical double layer and thermal radiation with the help of the Ellis nanofluid flow model through a complex symmetric wavy channel. The results of the present investigation are useful for the early detection of renal diseases and monitoring of disease progression because of the unique properties of gold nanoparticles. The role of gold nanoparticles as imaging agents, drug delivery antioxidant properties, biosensing, targeted therapy, and renal clearance makes them the perfect choice for renal diseases.

Insight into the thermal transport by considering the modified Buongiorno model during the silicon oil-based hybrid nanofluid flow: probed by artificial intelligence

This work aims to analyze the impacts of the magnetic field, activation of energy, thermal radiation, thermophoresis, and Brownian effects on the hybrid nanofluid (HNF) (Ag++silicon oil) flow past a porous spinning disk. The pressure loss due to porosity is constituted by the Darcy–Forchheimer relation. The modified Buongiorno model is considered for simulating the flow field into a mathematical form. The modeled problem is further simplified with the new group of dimensionless variables and further transformed into a first-order system of equations. The reduced system is further analyzed with the Levenberg–Marquardt algorithm using a trained artificial neural network (ANN) with a tolerance, step size of 0.001, and 1,000 epochs. The state variables under the impacts of the pertinent parameters are assessed with graphs and tables. It has been observed that when the magnetic parameter increases, the velocity gradient of mono and hybrid nanofluids (NFs) decreases. As the input of the Darcy–Forchheimer parameter increases, the velocity profiles decrease. The result shows that as the thermophoresis parameter increases, temperature and concentration increase as well. When the activation energy parameter increases, the concentration profile becomes higher. For a deep insight into the analysis of the problem, a statistical approach for data fitting in the form of regression lines and error histograms for NF and HNF is presented. The regression lines show that 100% of the data is used in curve fitting, while the error histograms depict the minimal zero error −7.1e6 for the increasing values of Nt. Furthermore, the mean square error and performance validation for each varying parameter are presented. For validation, the present results are compared with the available literature in the form of a table, where the current results show great agreement with the existing one.

Investigation of thermal radiation and joule heating effects on variable viscosity Casson nanofluid flow over a stretching sheet in Darcy–Forchheimer porous medium

Nanofluids possess unique thermal and rheological properties that offer significant advantages in enhancing heat transfer efficiency in various applications, such as heat exchangers, cooling systems, and microdevices. In this study, we investigate the combined effects of thermal radiation, Joule heating, variable viscosity, and a two-phase model on the flow behavior and heat transfer characteristics of a magnetohydrodynamic Casson nanofluid flowing over a stretching sheet in Darcy-Forchheimer porous media. The governing partial differential equations are converted into a system of first-order ordinary differential equations numerically solved using the bvp5c package in MATLAB. Consequently, the result indicates that the velocity profile increases with thermal radiation, variable viscosity, and viscous dissipation, decreasing with the magnetic field, permeability index, and Forchheimer coefficient. Also, the temperature profile shows an increase with the permeability index, viscous dissipation, and thermal radiation, but a decrease with the Forchheimer Coefficient, variable viscosity, and magnetic field. Additionally, the concentration profile exhibits an increase with the Forchheimer coefficient and permeability index, and variable viscosity while it decreases with viscous dissipation, magnetic field, and thermal radiation. Analyzing the skin friction coefficient reveals an increase with magnetic field and thermal radiation and a decrease with permeability index and Forchheimer coefficient as well as variable viscosity. Moreover, the local heat transfer rate demonstrates an increase with the variable viscosity, and magnetic field as well as the Forchheimer coefficient and permeability index. At the same time, it decreases with the viscous dissipation. Furthermore, the local mass transfer rate displays an increase with the magnetic field and thermal radiation and viscous dissipation, while it decreases with the variable viscosity as well as permeability index, viscous dissipation, and Forchheimer coefficient. Finally, the current findings are compared with that of the existing literature and a sound agreement was established.

Heat and Mass Transfer Effects on MHD Mixed Convective Flow of a Vertical Porous Surface in the Presence of Ohmic Heating and Viscous Dissipation

The present paper addresses the combined effects of thermal radiation and chemical reaction on steady MHD mixed convective flow of heat and mass transfer past a vertical surface under the influence of Joule and viscous dissipation. The governing system of the partial differential equations is transformed into the dimensionless equations using dimensionless variables. The dimensionless equations are solved numerically using two term perturbation technique and numerical solution as in graphically. The effects of the various parameters entering the problem on the dimensionless velocity, temperature and concentration fields within the boundary layer are discussed qualitatively. The velocity increases with an increase in Grashof number Gr, permeability parameter and solutal Grashof number Gm but decreases in magnetic parameter.

Free convective and radiating flow confined between vertical parallel MHD plates with heat transfer and uniform inclined magnetic field

The objective of this article is to investigate on the natural convective MHD flow of viscous fluid with assessment of mass and heat transfer effects. The flow is confined by two parallel plates. The walls of plates are assumed to be porous. The thermal radiation effects and inclined magnetic field applications are endorsed. One plate maintains the adiabatic phenomenon. The simplified form of problem is achieved with help of dimensionless variables. The analytical outcomes for given formulated problem are obtained with help of perturbation technique. Effects of various flow parameters involving to the problem are graphically impacted. It is claimed that velocity profile enhances due to modified Grashof number. An enhancement in heat transfer is subject to increasing the radiation parameter. Moreover, concentration profile reduces due to Reynolds number.

Mixed Convection Flow of MHD Casson Nanofluid over a Vertically Extending Sheet with Effects of Hall, Ion Slip and Nonlinear Thermal Radiation

This manuscript investigates the effects of viscous dissipation, Ohmic heating, nonlinear thermal radiation, chemical reactions, Hall current, and ion slip on the mixed convection flow of magnetohydrodynamic (MHD) Casson nanofluid over a vertically stretching sheet in a spongy medium. The strongly nonlinear ordinary differential equations (ODEs) derived from the governing equations are solved using a sixth-order, seven-stage Runge–Kutta (RK6) method in conjunction with the shooting technique. Numerical simulations are conducted using an open-source Python programming language. The study evaluates temperature, velocity, nanoparticle concentration, skin friction coefficients, Nusselt number (rate of heat transfer), and Sherwood number (rate of mass transfer) based on dimensionless parameters. Key findings reveal that increasing ion slip and Hall currents enhance the velocity profile in the x-direction, while the Casson parameter exerts a diminishing effect. The fluid temperature decreases with higher Hall current, Casson parameter, and ion slip values but increases due to nonlinear thermal radiation, the temperature ratio parameter, and the Eckert number. Furthermore, the chemical reaction parameter and Schmidt number reduce nanoparticle concentration within the boundary layer, with the Casson parameter amplifying this effect. The study also examines the rates of mass, heat, and momentum transfer near the surface under varying parameter influences, presenting results through comprehensive graphs and tables. To validate the numerical method, a comparative analysis is conducted against previous studies, demonstrating excellent agreement and thus confirming the reliability and accuracy of the computational approach.

Analyzing heat transfer behavior in two-dimensional Darcy–Forchheimer porous medium using magnetized nanoparticles

This study investigates the two-dimensional boundary layer flow and heat transfer of an incompressible fluid over a plate embedded in a Darcy–Forchheimer porous medium of magnetite ternary hybrid ferrofluid in the presence of suction or injection. It uniquely includes the effects of thermal radiation and viscous dissipation in the energy equation, offering a comprehensive analysis of the phenomena involved. The research focuses on three nanoparticle (NP) combinations of ferrofluid particles ( Fe 3 O 4 ) and metal oxide NPs ( CuO / TiO 2 ) dispersed in an aquatic base fluid with different volume fractions. The governing nonlinear partial differential equations are transformed into ordinary differential equations via similarity transformations and solved using the Runge–Kutta-based shooting technique. The study evaluates key physical quantities, such as the skin friction coefficient and Nusselt number, and examines the effects of dimensionless parameters, including the absorbent Reynolds number (Re), expansion ratio (α), Peclet number (Pe), Eckert number (Ec), NP volume fractions ( φ 1 , φ 2 , and φ 3 ) , porous medium parameter (r), and Darcy-porous medium parameter (F), on velocity and temperature profiles. The results indicate that increasing the porous medium parameters r and F leads to opposite shear stress effects in the dual-porosity medium. Higher Peclet number (Pe) and Eckert number (Ec) values enhance heat transfer rates within the thermal boundary layers. Moreover, elevated Reynolds number (Re) and expansion ratio (α) values result in opposing radial velocity profiles within the momentum boundary layers. This comprehensive analysis provides valuable insights into the complex interactions governing ternary ferrofluid flow and thermal performance in dual-porosity media, contributing to advancements in fluid system applications.

Thermal analysis on Ferro Casson nanofluid flow over a Riga plate with thermal radiation and non-uniform heat source/sink

Ferro hybrid nanofluids can be used in electronics and microelectronics cooling applications to reduce heat accumulation and efficiently remove surplus heat. These nanofluids aid to maintain optimum operating temperatures and reduce device overheating by enhancing the heat transfer rate. With this motivation, the aim of the present numerical analysis is to study the three-dimensional incompressible hybrid nanofluid flow over a slippery Riga surface by combining the Casson fluid model. Mathematical modeling is constructed with nanoparticles as Fe3O4 and CoFe2O4 with base fluid as water. The non-uniform heat source/sink and thermal linear radiation effects are taken into account with the Hamilton–Crosser thermal conductivity model. A system of nonlinear PDEs is produced by the proposed problem and then the relevant similarity variables are implemented to transform the set of partial differential equations and their accompanying boundary conditions into the coupled nonlinear differential equations with one independent variable. These modified ordinary differential equations (ODEs) were then successfully solved with the Runge–Kutta fourth-order method by combining via the shooting technique. With the aid of graphical representations, the effects of various influencing parameters were presented and analyzed comprehensively. Furthermore, the impacts of relevant parameters on heat transfer rates and shear stress are concisely discussed and illustrated in tabular forms. The significant findings include the enhancement of the radiation parameter increases the thermal boundary layer thickness and the thickness increases whenever surface experiences slippery conditions. The axial and transverse momentum of the fluid are controlled with the Casson parameter. An effective connection is noticed once the current numerical solutions are verified under particular conditions that were previously described.

Darcy-Forchheimer MHD micropolar water based hybrid nanofluid flow, heat and mass transfer features past on stretching/shrinking surface with slip and radiation effects

Hybrid nanofluids (HNF) play a vital role in enhancing the heat transfer characteristics of all types of traditional fluids, both in industrial and experimental applications. In this regard, the laminar two-dimensional (2D) boundary layer magnetohydrodynamic (MHD) Darcy-Forchheimer flow, heat transfer, and mass transfers characteristics of Cu–MoS2/micropolar water-based hybrid nanofluid have been considered over a stretching/shrinking surface. The thermal radiation and partial slip effects are considered in a porous medium. The governing partial differential equations (PDEs) are transformed into ordinary differential equations (ODEs) using appropriate similarity transformations. The equations are numerically solved using the shooting method in Maple software, and dual solutions are obtained for different ranges of the applied parameters. The effects of the different physical parameters and nanoparticle volume fractions on velocity, microrotation, temperature, and concentration profiles along with skin friction, couple stress, Nusselt and Sherwood numbers are examined. The main findings of this study show that the velocity profiles decrease with an increase in the suction, the Darcy-Forchheimer number, velocity slip, magnetic and micromaterial parameters, while oppositely, it increases with an increase in nanoparticle volume fractions. Moreover, an increase in the magnetic field, nanoparticle volume fractions, and thermal radiation increases the temperature profiles, while an increase in the Prandtl number, suction, and thermal slip parameters decreases it. An increase in nanoparticle volume fractions decreases skin friction, the couple stress coefficient, and the Nusselt number, but increases the Sherwood number with the variation of suction.

Variation of fluid characteristics in radiated Sutterby fluid flow over a stretched surface exhibiting thermophoretic phenomenon

This research introduces novel theoretical assumptions through the use of a non-Newtonian Sutterby model with variable properties, demonstrating significant advancements in thermal conductivity and diffusivity, which enhance heat and mass transfer in fluids, particularly under magnetic field exposure. The study is notable for its comprehensive examination of the effects of thermal radiation and viscous dissipation within a porous medium. Additionally, it explores the role of suction velocity to provide a deeper understanding of transport phenomena. Following the Darcy hypothesis, the fluid flow is modeled as resulting from the linear stretching of an elastic sheet in a saturated porous medium. The core physical model, comprising equations of mass, motion, concentration, and energy, is transformed into ordinary differential equations using appropriate similarity transformations. Employing the shooting technique, the numerical solution to the problem is obtained. The research uncovers and quantitatively analyzes intriguing physical parameters influencing velocity, concentration, and temperature fields. These parameters are further investigated both numerically and graphically, providing valuable insights into their effects. Quantitative outcomes include enhanced thermal and concentration fields by magnetic field parameter, the porous parameter and the viscosity parameter and improved the rate of mass transfer by both suction and thermophoretic parameters, highlighting the model’s efficacy in optimizing fluid dynamics especially under magnetic fields. The obtained outcomes were juxtaposed with previous studies, revealing a significant level of agreement.

Simulation of MHD-Casson hybrid nanofluid dynamics over a permeable stretching sheet: effects of heat transfer and thermal radiation

Simulation of MHD-Casson hybrid nanofluid dynamics over a permeable stretching sheet: effects of heat transfer and thermal radiation

Influence of activation energy and variable thermal conductivity on magneto-convective nonlinear thermo-radiative Casson nanofluid containing motile microorganisms over a sinusoidal surface

The activation energy of convective-radiative nanoliquids with sinusoidal walls has garnered significant academic interest in recent years. This focus arises due to the pivotal applications of nanoparticles in thermal engineering, industrial processes, and medical sciences. This article investigates the magnetohydrodynamic heat transfer characteristics of Casson nanofluids containing microorganisms influenced by an oscillatory surface. The study incorporates temperature-dependent viscosity and utilizes Buongiorno’s mathematical model to account for nonlinear thermal radiation, Brownian motion, and thermophoretic effects from using nanomaterials in Casson fluids. These effects enhance thermal conductivity, improving the heat transportation phenomenon while considering gyrotactic microorganism density distributions. The boundary layer flow problem is formulated using partial differential equations and associated boundary conditions, subsequently numerically simulated using the bvp4c function. The investigation explores the thermal behavior of nanoparticles in the presence of bioconvection phenomena, Lorentz force, chemical reactions, and activation energy. As a result, this model addresses variable thermal conductivity and bioconvection aspects in Casson nanofluids over a sinusoidal surface. Numerically computed results for the Nusselt number, motile density, and Sherwood number provide insights into several essential features. The findings reveal that an increase in the Casson fluid parameter correlates with a decreased velocity profile. The assumptions of variable thermal conductivity and temperature-dependent viscosity prove more effective in raising the temperature of nanoparticles. The nanoparticle concentration profile rises noticeably for smaller Schmidt number Sc values when the activation energy parameter is higher than larger Sc values. Additionally, the presence of microorganisms in Casson nanofluids leads to increased temperatures due to an elevation in the bioconvection Rayleigh number. Moreover, heightened oscillating frequency parameters decrease nanoparticle concentration and microorganism density. Including activation energy and oscillating frequency parameters further enhances the understanding of nanoparticle concentration and microorganism density dynamics, offering valuable contributions to theoretical research and practical applications across multiple interdisciplinary fields.

Uncertain effects of thermal radiation and magnetic field in the micropolar fluid flow through porous channel walls with hybrid nanoparticles

Uncertain effects of thermal radiation and magnetic field in the micropolar fluid flow through porous channel walls with hybrid nanoparticles

Exploration of irreversibility process and thermal energy of a tetra hybrid radiative binary nanofluid focusing on solar implementations

Abstract Thermal energy from the Sun comes mostly from sunlight. These energies might be used in photovoltaic cells, sustainable power systems, solar light poles, and water-collecting solar pumps. This age studies solar energy and how direct sunshine might improve solar panel efficiency. Solar energy, especially solar tiles, is widely used in manufacturing today. The literature includes a modified Buongiorno hybrid nanofluid prototype. There are no studies that have examined the impact of tri-hybrid and unique tetra hybridity nanomolecules integrated with the Buongiorno nanofluid prototype on liquid moving on a flexible surface. This study examines the effects of an improved Buongiorno tetra hybrid nanoliquid prototypical with Buongiorno and Tiwari–Das nanofluid on magnetized double-diffusive binary nanofluid with cross fluid and Maxwell liquid flowing with variant thermal conductance over a porous medium. Different profiles include diffusion thermo and thermo diffusion. The LobattoIIIA scheme’s convergence and stability are examined in terms of residual error, mesh points for ordinary differential equations (ODEs), and boundary conditions. Leading equations about liquid flow continuity, impetus, temperature, and concentricity are obtained using continuity, conservation of momentum, the second law of thermodynamics, Fick’s second law of diffusion, and boundary layer expectations. The system of partial differential equations obtained from the given assumption becomes a system of ODEs and well-established LobattoIII. Their numerical solution is obtained using a numerical technique. Statistical charts and tables provide numerical solutions. The heat transport rate of tetra-hybrid nanomolecules increases dramatically, unlike tri- and di-hybrid nanomolecules. The improved Buongiorno tetra hybrid nanofluid (BTHNF) model produces more heat when radiation Rd {\rm{Rd}} , Brownian diffusion Nb {\rm{Nb}} , and thermal conductivity are increased. The data show that the diffusion factor L L , Brinkman number Br {\rm{Br}} , and Reynolds number Re increase entropy production, but Bejan number reduces it owing to an increase in Be {\rm{Be}} and Re \mathrm{Re} . A statistical regression study shows that retaining the Maxwell fluid parameter constant and increasing the Weissenberg number We {\rm{We}} decrease the drag coefficient error. A BTHNF model containing tetra hybrid nanoparticles has not been utilized to examine heat and mass transferences in non-Newtonian fluids, considering diffusion, thermo, and thermo diffusion. Entropy generation in a binary fluid with tetra hybrid nanoparticles and BTHNF has not been studied. Tetra hybrid nanofluid is not mentioned in the literature. This effort aims to create a new tetra-hybrid nanofluid model. This article is novel because it investigates the effects of thermal radiation, thermal conductivity, porosity, Darcy–Forchheimer, and Buongiorno models on a tetra-hybrid nanofluid flow under an extensible sheet.

Thermal optimization of buoyancy driven radiative engine-oil based viscous hybrid nanofluid flow observing the micro-rotations in an inclined permeable enclosure

Thermal enhancement of engine oil plays an important role in a variety of industrial applications including heat exchangers, automotive cooling systems, renewable energy systems, biomedical devices, and advanced manufacturing processes. Considering the high demand in industry, present investigation explores thermal optimization of engine oil contained in a porous inclined cavity involving dispersion of hybrid nanoparticles along with inclusion of micropolar fluid flow phenomena. Numerical analysis is performed on the micropolar nanofluid containing iron oxide and molybdenum disulfide while considering the effect of thermal radiation, buoyancy force, viscous dissipation, magnetic field’s strength, porosity, and vortex viscosity. Numerical solutions of the dimensionless governing equations are provided through utilization of FVM. The coupling of velocity and pressure terms was achieved through implementation of SIMPLE algorithm. The results are illustrated through streamlines, contours, velocity, temperature profiles and heat flux. The outcomes revealed that an augment in Hartmann number and thermal radiation parameter results in higher heat flux rate. The incrementation in Hartmann number disrupted the flow resulting a reduction in the size of major vortices and similar trend is noted in case of temperature profile for the said parameters. The outcomes complement the continuing efforts to improve the thermal management of various applications and offer insightful information for optimizing engine oil compositions.

Self-Adaptive Turbulence Eddy Simulation of Supersonic Combustor Considering Thermal Radiation

The newly developed self-adaptive turbulence eddy simulation (SATES) method coupled with three turbulent combustion models, i.e., the finite-rate model, eddy-dissipation model, and steady laminar flamelet model, is used to numerically study the non-premixed supersonic hydrogen combustion in a DLR (German Aerospace Center) model scramjet combustor with a wedge flame holder. The study investigates the interactions of the shock waves and the flowfields as well as the flame structures. The SATES-based combustion simulation results demonstrate satisfactory agreement with the available experimental data. The study also explores the effect of fuel injection temperature on the combustion process and reveals that an increase in hydrogen temperature improves combustion efficiency. Additionally, thermal radiation effects are considered with the discrete ordinates method/weighted-sum-of-gray-gases method. The results indicate that thermal radiation heat transfer reduces the flame temperature and significantly affects the flame shape and temperature fluctuations. Also, radiation heat flux is an important factor and should be included in supersonic combustion simulations. The study demonstrates the potential of the SATES method for complex supersonic combustion and also provides a reference for thermal radiation in supersonic combustion.