Heat Flux Model Research Articles

Mechanistic model of critical heat flux in rod bundles based on a high-precision subchannel code

A mechanistic model for predicting critical heat flux (CHF) in rod bundles is developed based on the high-precision subchannel code ATHAS. To account for the non-uniform distribution of quality in subchannels caused by the presence of mixing vane grids (MVGs) and guide tubes (GTs), further subdivision of conventional subchannels and the incorporation of MVG crossflow models are implemented in ATHAS to provide a more detailed local flow field for the CHF model. The CHF mechanism model is developed based on the concepts of bubble crowding and assumption of local phenomenon. An equivalent-tube concept is proposed to convert the turbulent intensity distribution on the tube surface to that on the rod bundle surface. The present model is implemented in ATHAS and evaluated against CHF experimental data of rod bundles under the conditions of interest for pressurized water reactors (PWRs). The predicted results show good agreement with the experimental CHF data, with an average error and root mean square of 0.99% and 4.69%, respectively, for a total of 601 data points. Furthermore, owing to the use of the subchannel subdivision method, the present model does not require any cold wall effect correction and can accurately predict the radial position of CHF.

Numerical illustration of diffusive flow of blood-based tri-hybrid nanofluid generated by a curved stretching sheet using law of porosity

The study of flow of blood through the blood vessels carries nanoparticles which opens new ways in the research. This study explores one such flow of trihybrid nanoparticles suspended in blood over a curved stretching surface which undergoes the Darcy-Forchheimer porosity model. The analysis employs Cattaneo-Christov heat flux model along with chemical reaction, linear heat source allowing the surface to slip with heat and mass convection. The trihybrid nanofluids consist of a mixture of titanium dioxide, iron oxide, and silica nanoparticles mixed with base fluid (blood) to generate TiO 2 - Fe 3 O 4 - SiO 2 /blood hybrid nanofluids. Runge-Kutta-Fehlberg 4th–5th order technique, a robust numerical technique, was employed to obtain mathematical solutions. Throughout the numerical process, all parameters, except those under examination, were kept at their default values. Additionally, various plots were generated based on numerical results to illustrate the obtained data. The findings indicate that an increase in the Forchheimer number and porosity results in a reduction in the velocity profile. Furthermore, an increase in the radiation parameter and thermal Biot number leads to an increase in the temperature profile, while the temperature profile decreases with an increase in the thermal relaxation parameter. Additionally, an increase in the chemical reaction parameter and concentration Biot number results in an increase in the concentration profile. Moreover, higher Brinkman and Prandtl numbers enhance the Nusselt number.

Evaluation of homogeneous-heterogeneous chemical response on Maxwell-fluid flow through spiraling disks with nonlinear thermal radiation using numerical and regularized machine learning methods

ABSTRACT The present study addresses the effects of nonlinear thermal radiation and heat fall/rise on the thermal radiated viscoelastic fluid flow through spiraling disks with a homogeneous and heterogeneous chemical response. The properties of the Cattaneo-Christov heat flux model, a revised model of conventional Fourier’s law that predicts thermal relaxation properties, are examined in detail. The rotation of both the disks in the same and opposite directions is evaluated. The effect of heterogeneous-homogeneous chemical reactions is also considered in the present communication, making the study reasonably adaptable. The coupled partial differential equations, such as energy, momentum, and concentration, are transformed into ordinary differential equations by von Kármán variables. The outcomes of the present work confirm that flow behavior is reversed due to stretching action. Velocity and pressure profiles are reduced with the impact of Deborah’s number. In addition, it is noticed that increasing heterogeneous-homogeneous reaction parameters decreases the fluid concentration. Numerically computed values are compared with the predicted results using L.R. regularized L.R. and regularized S.V.R. It is observed that the regularized L.R. method outperformed the other two machine learning methods. Graphical illustrations of axial, radial, and tangential flows and concentration and temperature profiles are illustrated in graphs.

Advanced numerical simulation techniques in MHD fluid flow analysis using distributed fractional order derivatives and Cattaneo heat flux model

AbstractThis study investigates the flow and heat transfer characteristics of a second‐grade fluid over a flat surface with variable heat flux. Utilizing a mathematical model based on distributed order fractional derivatives, we offer a more precise representation of non‐Newtonian fluid behavior. The associated highly nonlinear equations are tackled numerically through an innovative amalgamation of the finite difference scheme and the technique. Our investigation thoroughly evaluates the influence of several critical parameters on the fluid's motion and thermal characteristics. Notably, the magnetic parameter significantly inhibits the fluid's velocity, illustrating the impact of magnetic forces. Additionally, the power law parameter leads to a decrease in both velocity and temperature profiles, highlighting its influence on fluid dynamics. Furthermore, changes in the Reynold number and the second‐grade fluid parameter are observed to cause a substantial increase in skin friction, by approximately 40% to 50%. These simulation results provide valuable insights into the complex interaction between fluid flow and heat transfer characteristics, enhancing our understanding of such systems in industrial applications.

Convective flow of a magnetohydrodynamic second-grade fluid past a stretching surface with Cattaneo–Christov heat and mass flux model

Abstract This research delves into dynamics of magnetohydrodynamic second-grade fluid flow influenced by the presence of gyrotactic microorganisms on a stretching sheet. The study takes into account various factors such as thermal radiation, chemical reactivity, and activation energy, all of which contribute to the complex behavior of fluid flow in this system. The interaction between the magnetic field and the fluid, combined with the biological aspect introduced by gyrotactic microorganisms, adds complexity to the overall analysis. The mathematical model is presented in the form of partial differential equations (PDE)s. Using the similarity variables, the modeled PDEs are transformed into ordinary differential equations. Homotopy analysis method is used for the solution of the modeled equations. After a detailed insight into this investigation, it is established that the velocity distribution declined for growth in magnetic factor and second-grade fluid parameter. The thermal characteristics are augmented for the greater values of radiation, thermophoretic and Brownian motion factors, while these profiles are weakened for upsurge in thermal relaxation time factor and Prandtl number. The concentration characteristics declined with the enhancement in Schmidt number, mass relaxation time, chemical reaction, and Brownian motion factors, while they amplified with enhancement in activation energy and thermophoresis factors. The microorganisms’ profiles are the declining functions of bioconvection Lewis and Peclet numbers. This study included a comparative analysis, which aligns closely with existing research, demonstrating a strong concordance with established findings.

Thermophoretic particle deposition in a nanofluid flow across a disc with non-fourier heat flux: An investigation using tangent hyperbolic model

Non-Newtonian nanofluids are attracting the attention of researchers and academics due to the high heat transmission rates that they possess. To improve thermal devices and exchangers, the researchers come up with innovative and expense-effective methods. One of the advanced technological approaches that can be utilized to enhance the thermal performance of devices is the utilization of nanofluids. This non- Newtonian nanofluid possesses the advanced properties of increasing heat transfer and destroying harmful bacteria. For this purpose, the present theoretical work is to explore the heat and thermophoretic particle deposition analysis on the tangent hyperbolic nanofluid flow over the rotating porous disk with presence of non-Fourier heat flux model and nanoparticle aggregation effect. Darcy-Forchheimer fluid model is adopted to develop the fluid flow system. Furthermore, the nanofluid’s viscosity and thermal conductivity are expressed through advanced modeling, employing the modified Krieger-Dougherty model for viscosity and the Maxwell-Bruggeman model for thermal conductivity. The nanoparticles and base fluid involved in this context are Molybdenum disulfide ( Mo S 2 ) and Water/carboxyl-methyl cellulose (CMC) respectively. The mathematical representation of the fluid flow and energy propagation involves a system of coupled partial differential equations (PDEs). The system of partial differential equations (PDEs) is transformed into non-dimensional ordinary differential equations (ODEs), which are then solved both analytically and numerically using the Homotopy Analysis Method(HAM) and Runge-Kutta-Fehlberg (RKF) method along with shooting technique. Exploring the graphical representation reveals a comprehensive analysis of key factors influencing velocity, temperature, and concentration. Through innovative visualization, these parameters take center stage, providing insights into their intricate interplay and dynamic relationships. The heat transfer rate is enhanced 0.24% and 1.4% by rising the values of thermal relaxation parameter and Weissenberg number. Also, the mass transfer rate is accelerated 0.8% and 0.14% due to enhancing the values of thermophoretic coefficient and thermophoresis parameter.

Hybrid RANS/LES modeling of hypersonic turbulent boundary layers with cold walls

Various strategies for hybrid RANS/LES modeling of hypersonic turbulent boundary layers subjected to strong wall-cooling are developed and analyzed. By defining a turbulent thermal length scale, the eddy viscosity and diffusivity of the hybrid model are calculated by the same formula, ℓ2ω. This allows a similar blending of the length scales and the development of analogous dynamic models for turbulent stress and heat flux. The dynamic procedure is applied to heat transfer by equating norms, rather than invoking least-squares with a lower bound, which improves robustness. The shielding function, as used in detached eddy simulations models, is revised to prevent a spurious early switch from the RANS to the LES mode. This revision significantly improves the accuracy of hybrid models on coarse grids. Finally, the proposed models are tested and validated for Mach numbers between 2.5 and 14, and wall-to-recovery temperature ratios between 0.18 and 1.

Effects of MHD and thermal radiation on non-Newtonian fluid with Cattaneo–Christov heat over a stretching flow surface

In this study, we are investigating the flow of an incompressible Williamson fluid using a Cattaneo–Christov heat flux model, with consideration for a magnetic Reynolds number that is not high. This fluid flows over a linearly stretched 2-D surface and is affected by a magnetic field, thermal radiation-diffusion, and heat generation. To model the Williamson flow, we apply a boundary layer approximation and develop the ordinary differential equations. The system of differential equations is transformed into a system of ordinary differential equations using a suitable transformation. We utilize the Iterative Runge–Kutta fourth-order scheme to numerically solve the boundary conditions associated with the nonlinear, dimensionless ordinary differential equations. Graphical representations of the results are employed to analyze the impact of physical properties on velocity, temperature, and concentration, with the numerical results presented in tabular form. Upon comparing our findings with previously published results, we have found them to be in good agreement. The velocity decreases as the Williamson fluid factor gradually increases. Williamson fluids are recognized for their shear thinning behavior, wherein viscosity decreases as the shear rate increases. However, higher parameter values can lead to increased fluid viscosity, potentially reducing the degree of shear thinning. This phenomenon results in a more uniform viscosity profile across varying shear rates, contributing to a reduced velocity distribution within the fluid.

Numerical investigation and experimental validation of aluminized propellant combustion under high pressures: Critical effects of heat feedback

Aluminum is a common metal fuel in propellants, but its effects on the burning rate and the underlying mechanism are still unclear. Numerical calculations and temperature measurement experiments were carried out within the pressure range of 0.1–9 MPa, and the effects of the pressure and the ammonium perchlorate (AP) particle size on the combustion characteristics of aluminized propellants were studied. First, based on a two-dimensional micro-scale combustion model of an AP/hydroxyl‑terminated polybutadiene (HTPB) propellant, by considering the “heat sink” effect of aluminum on the burning surface and the chemical reaction of aluminum in the gas phase, a numerical calculation model of heat flux coupled with the steady-state combustion of an aluminized propellant was established. The flame structure of an aluminized propellant obtained by this model conformed to the multi-flame structure and could correctly reflect the influence of the AP particle size and pressure on the burning rate and other combustion characteristics. Subsequently, the influence of radiation heat feedback was further introduced into the model, which greatly improved its accuracy in predicting the burning rate at low pressures of 1–3 MPa. More importantly, the temperature distributions of the propellants were measured using embedded tungsten–rhenium thermocouples, and the flame temperature was obtained by further processing the temperature measurement data according to the thermocouple response characteristics. The temperature measurement results showed that with the increase in the pressure and the decrease in the size of the AP particles, the temperature gradient increased significantly, the flame temperature increased slightly, and the burning rate of the propellant increased. By analyzing how the temperature gradient and the burning rate changed with pressure, it was found that the conduction heat feedback was important to determine the burning rate.

Effect of inclined magnetic field and chemical reaction on Casson fluid flow over a stretching surface with Cattaneo–Christov double diffusion

This investigation discusses the significance of studying the behavior of non-Newtonian fluids, specifically the Casson fluid, subjected to an electrically conducting and stretching sheet. The study also explores the effects of an aligned magnetic field, Cattaneo–Christov double diffusion, viscous dissipation and chemical reactions on heat and mass transfer, respectively. The partial differential equations governing the flow problem are transformed into ordinary differential equations through the utilization of similarity transformations. Furthermore, the shooting technique is implemented in MATLAB to solve the ODEs. The influence of physical parameters, such as the magnetic field parameter, Eckert number, Prandtl number and chemical reaction parameter, on the velocity profile, temperature distribution, concentration profile, skin friction coefficient, Nusselt number and Sherwood number is studied and presented in graphical and tabular forms. It is found that increasing the Prandtl number causes a drop in the temperature profile. Moreover, the presence of thermal radiation and the Eckert number significantly amplifies the temperature distribution. When the magnetic number undergoes a substantial increase, there is a notable decrease in the velocity profile, and simultaneously, the temperature profile experiences a noticeable rise. Additionally, increase in the chemical reaction parameters leads to a decrease in the concentration profile. The skin friction coefficient, local Nusselt number and Sherwood number exhibit significant reductions as the Casson parameter increases. Additionally, a MATLAB built-in function named bvp4c is incorporated to verify the computed results. The practical implications of the Cattaneo–Christov heat flux model include microelectronics, microfluidic devices, processes involving rapid heating or cooling, such as laser welding or pulsed laser ablation and heat transfer in biological tissues.

MHD flow of Carreau fluid over a curved stretching surface with Cattaneo–Christov heat flux model and chemical reaction

The numerical investigation of the mixed convection transport of Carreau fluid due to stretched sheet, along with the combined effect of MHD and first-order chemical reaction is taken into account. The energy equation is modified by considering the effect of the Cattaneo-Christov heat flux. The boundary layer equations of the problem are transformed into the structure of dimensionless coupled ordinary differential equations by utilizing the appropriate similarity variables. These equations of the problem are solved numerically via BVP4c. The main outcome of the problem is that the relaxation time enhanced the fluid temperature while the chemical parameter declined the concentration profile. Moreover, the mixed convection effect increases the fluid velocity of the stretching sheet. The physical quantities like fluid velocity, temperature, concentration, friction at the wall, mass, and heat flux for the variation of several pertinent parameters are discussed graphically and in tabular form.

Identifying Challenges to 3D Hydrodynamic Modeling for a Small, Stratified Tropical Lake in the Philippines

Three-dimensional hydrodynamic modeling for small, stratified tropical lakes in the Philippines and in Southeast Asia in general is not deeply explored. This study pioneers investigating the hydrodynamics of a small crater lake in the Philippines with a focus on temperature simulation using a Fantom Refined 3D model that has been tested mostly for temperate and sub-tropical lakes. The lake’s monthly temperature during the dry season served as a reference for the model’s initial condition and validation. For the simulation to proceed, input data such as weather, inflow, and bathymetry were prepared. In the absence of hourly meteorological data from local weather stations, this paper adopted the satellite weather data from Solcast. Simple correlation analysis of daily weather data between local stations and Solcast showed valid and acceptable results. Inflow values were estimated using the rational method while the stream temperature was estimated from a regression equation using air temperatures as input. The validated satellite-derived data and runoff model can therefore be employed for 3D modeling. The simulations resulted in extremely higher temperatures compared with those observed when using previous default model settings. Direct modifications were then applied to weather parameters, compromising their integrity but resulting in reasonable profiles. By adding scaling factors to heat flux equations and multiplying their components by 0.75 (shortwave), 1.35 (longwave), 0.935 (air temperature), and 0.80 (wind), better results were achieved. This study identifies several challenges in performing 3D hydrodynamic modeling, such as paucity in input hydro-meteorologic and limnologic data and the need for heat flux model improvement. Overall, this study was successful in employing 3D hydrodynamic modeling in a tropical lake, which can pave directions and serve as an excellent reference for future modeling in the same region.

Estimation of impact of non‐local ion heat flux model on transport simulation for DEMO‐relevant scrape‐off layer plasma

AbstractIn a fusion DEMOnstration reactor (DEMO)‐relevant scrape‐off layer plasma (SOL), whose collisionality is lower than in the SOLs of present‐day tokamaks, kinetic effects are predicted to reduce the plasma heat conductivity along the magnetic field below the value obtained with the classical Spitzer–Harm model. As a part of ongoing efforts to improve the predictive capability of SOL heat transport calculations, we have implemented the non‐local heat flux model proposed by [Luciani, Mora and Virmont, Phys. Rev. Lett. 51 (1983) 1664–1667] (here referred to as the LMV model) in the integrated SOL–divertor simulation code SONIC in order to account for the kinetic effect on the heat conduction due to the parallel streaming of rapidly moving particles. Our transport simulations for the Japanese demonstration tokamak reactor concept, JA DEMO, show that the LMV model yields a significantly reduced ion parallel conductive heat flux density both on the low‐ and high‐field side of the upstream SOL. The heat flux obtained with the LMV model seems to be consistent with earlier kinetic simulations of tokamak ion transport. As a consequence of the reduced heat flux, a significant increase in the ion temperature and a decrease in the density have also been found over a broad area of the upstream SOL.

Thermodynamic analysis of EMHD ternary nanofluid flow with shape factor effects over a shrinking sheet: A non-Fourier heat flux model

The investigation of the flow characteristics of ternary hybrid nanofluids through a contracting sheet has considerable importance due to its potential for achieving exceptionally high rates of heat transfer. The ternary hybrid nanofluid then absorbs heat from the surface and carries it away. The objective of this study is to analyze the influence of couple stress and activation energy parameters on the flow of a ternary hybrid nanofluid ( H 2 O + MWCNT + ZnO + Al 2 O 3 ) through a contracting sheet with electric forces and convective boundary conditions. The heat flux model created by Cattaneo and Christov is utilized to examine the mechanism of heat transmission. The equations necessary to depict the problem have been transformed into a system, which has subsequently been resolved using the bvp4c solver (MATLAB built-in function). It is found that there is a rise in the Bejan number with the increase in the couple stress parameter. An increase in the volume percentage of multi-walled carbon nanotubes ( ϕ MW ) is observed to result in an augmentation of entropy generation . It has been observed that there is a fall in the friction factor when the couple stress parameter rises and at 0 ≤ Ed ≤ 0.6 , (electric field parameter), the friction factor is seen to rise at a rate of 0.638797 (Platelet) and (0.638784). A positive correlation is observed between the thermal relaxation parameter ( ϒ ) and fluid temperature, indicating that a rise in the former leads to an increase in the latter. It is discovered that, when 0 ≤ ϒ ≤ 0.3 , the Nusselt number rises by 0.022587 (Platelet) and 0.022275 (Cylinder). There is a negative correlation between the upsurge in the activation energy parameter ( Eg ) and the corresponding rise in the Sherwood number. At 0 ≤ Eg ≤ 3 , the Sherwood number is seen to decline at a rate of 0.0321 (Platelet) and 0.03208 (Cylinder).

Heat transfer analysis of MHD Prandtl-Eyring fluid flow with Christov-Cattaneo heat flux model

The current problem focuses on the heat transfer analysis of the non-Newtonian Prandtl-Eyring fluid flow under an applied magnetic field over a variable stretching sheet. The variable stretching is assumed because most of the practical situations have variable stretching surfaces. In addition, heat transfer is a very important phenomenon in many applications like the extrusion of sheets, cooling of plants, etc. Thus, heat transfer is estimated with the Christov-Cattaneo heat conduction law to get more realistic results. The physical problem is mathematically modeled with all these assumptions, it yields the boundary value problem of the coupled nonlinear partial differential equations. The governing partial differential equations are first transformed into ordinary differential equations by employing a set of similarity transforms. And, the obtained ordinary differential system is numerically simulated with the shooting method for different parametric conditions. The proposed algorithm is quite efficient and implemented to solve the nonlinear governing equations very efficiently. Variations in fluid momentum and thermal energy are captured in graphs by varying flow govern parameters. In addition, the surface drag coefficient and reduced Nusselt number are computed and analyzed. For the validation of the computed results, a comparison is established with existing literature, it can be shown that computed results matched very well with reported literature. It is observed that both fluid parameters ( α , β ) have different effects on fluid velocity i.e. fluid parameter α increases it while fluid parameter β decelerates it. Also, the applied magnetic field produces Lorentz force which works in the opposite direction and hence it decelerates the fluid motion significantly. The drag force coefficient of variable stretching is higher and hence this surface is less favorable for fluid movement as compared to linear stretching. In addition, the fluid temperature cools down if the thermal relaxation phenomenon is considered.

Thermal Rectification across an Asymmetric Layer Carbon Nanotube van der Waals Heterostructure.

The exceptional thermal conductivity and strength of carbon nanotubes (CNTs) position them as outstanding materials for thermal conduction. The intriguing properties introduced by van der Waals (vdW) heterojunctions have also captured the interest of researchers. However, further refinement of the research concerning the integration of these two elements is required. In our study, a vdW heterostructure with asymmetric layer nesting of multiwalled CNTs (ALCNTs) is devised, with a specific focus on the model's heat flux and thermal rectification (TR) properties, which are analyzed using nonequilibrium molecular dynamics (NEMD). Notably, the greatest TR ratio is observed in the connection of three-layer and single-layer ALCNTs. Moreover, multilayer variable-length nested models exhibit a sluggish TR ratio. An examination of the interface thermal resistance (ITR) reveals that the maximum ITR in the multilayer nested model resides at the rightmost interface. However, it is essential to highlight that the determinant of the TR ratio and heat flux in the multilayer nested model is not the maximum ITR of the rightmost interface but rather the ITR of the outermost layer on the left. Additionally, the impacts of the defect density, length, temperature difference, and hydrogenation on the model's heat flux and TR are explored, yielding noteworthy conclusions. For instance, defects in the outer CNT have a minimal influence on the heat flux and TR compared with those in the inner CNT. As the length increases, the heat flux initially decreases and then increases. Hydrogenation significantly enhances the model's heat flux but does not favor the TR. Our study contributes to advancing the understanding of CNT vdW heterojunctions and offers valuable insights for their practical applications.

Unsteady magnetohydrodynamic hybrid nanofluid flow over a rotating disk with viscous dissipation and Cattaneo–Christov heat flux model

This work addresses unsteady MHD flow of hybrid nanofluids (MWCNTs−Fe3O4)/H2O over a rotating disk with viscous dispassion and the Cattaneo–Christov heat flux model. The boundary layer flow-directing PDEs were converted into systems of dimensionless coupled nonlinear ODEs using the similarity conversion technique. Using the spectral quasilinearization method (SQLM), the resulting nonlinear momentum and energy equations were then numerically solved along with their boundary conditions. For the preparation of (MWCNTs−Fe3O4)/H2O hybrid nanofluid with shape factor n1=n2=3, it is specified that 5% of MWCNTs, 20% of Fe3O4, and 75% of H2O be taken. Using graphs and tables, the effects of more noticeable parameters on the thermal flow fields and velocity were thoroughly investigated. The results show that as the value of the unsteady parameter increased, the momentum and thermal boundary layer thickness decreased. The local heat transfer rate improves by nearly 20% as 0.2 volume of Fe3O4 nanoparticles dispersed in 0.1 volume of MWCNTs and 0.7 volume of H2O nanofluid. The finding of this study is noteworthy because it indicates that the (MWCNTs−Fe3O4)/H2O hybrid nanofluids exhibit superior flow distributions and good thermal property stability when compared to their mono counterparts.

Entropy generation on MHD Eyring-Powell hybrid nanofluid flow over a curved stretching sheet with shape factors and the Cattaneo–Christov heat flux model: A comparative study

Entropy generation on MHD Eyring-Powell hybrid nanofluid flow over a curved stretching sheet with shape factors and the Cattaneo–Christov heat flux model: A comparative study

Numerical heat transfer to LBE flow in a wire-wrapped 19-rod bundle using an OpenFOAM-based solver: fourParameterFoam

The LBE-cooled fast reactor (LFR) has received significant attention due to its diverse applications. However, numerical heat transfer simulations encounter challenges with lead-bismuth eutectic (LBE) due to its low Prandtl number and high molecular thermal diffusion, often resulting in an overestimation of heat transfer using the simple gradient diffusion hypothesis (SGDH). This study aims to improve the prediction accuracy of heat transfer to LBE in numerical models by developing a solver, named fourParameterFoam, based on the turbulent model SST k-ω and algebraic heat flux model (AHFM) kθ-ɛθ within the OpenFOAM framework. The performance of SGDH models and AHFMs is compared based on heat transfer experiments in vertical tube flow with LBE. The behavior of the turbulent Prandtl number (Prt) under various flow conditions is concluded based on the SST k-ω-kθ-ɛθ model. Additionally, the applicability of the SST k-ω-kθ-ɛθ model in complex flow is validated through heat transfer experiments in a wire-wrapped 19-rod bundle with LBE flow. Local temperature variations on the heated rod surface and sub-channels are analyzed to elucidate the thermal development process in the bundle. The impact of wire spacers on flow behavior is summarized using visualization techniques, and the suitability of corresponding empirical Nusselt number correlations in LBE flow is evaluated.

Cattaneo-Christov heat and mass fluxes model of Casson fluid employing non-Fourier double diffusion theories with ion slip and Hall effects

It is vitally important to comprehend non-Newtonian fluids flow behaviour from an industrial perspective. Non-Newtonian fluids are needed for a number of industrial and technical processes, including the production of paper, photographic films, and polymer sheet extrusion. There are several industrial applications for heat and mass transfer. However, thermal and solute relaxation time phenomena can't be predicted by classical heat and mass transfer laws (Fourier and Fick laws). This work aims to apply the modified Ohm law to thermal and mass transfer which are based on Fick's and generalized Fourier principles, respectively. The current study examines the three-dimensional Darcy-Forchheimer flow of non-Newtonian fluid “Casson fluid” via porous medium with ion slip and Hall effects across a stretched sheet. Thermophoresis and Brownian motion aspects are also considered. The diffusion phenomena are modelled using the Boungrino model. The modified Buongiorno model (MBM) for nanofluids is used to investigate the enhancement of heat transport. Together with practical nanofluid properties, it covers the mechanics of thermo-migration and random motion of nanoparticles. By adding the appropriate similarity transformations, this collection of (PDEs) that reflect the mathematical model is transformed into an (ODEs) system, which it is subsequently resolved utilizing the Lobatto IIIA technique's powerful computing capabilities via Matlab software. Data visualisations and numerical examples are presented considering many physical restrictions affect the fluctuation of velocities, temperatures, concentration, dimensionless shear stress, Nusselt number, and Sherwood number. According to certain findings, the existence of Hall and ion slip effects, and other factors contribute to an increase in horizontal velocity distribution. Furthermore, Fourier's law produces a wider temperature distribution than the Cattaneo-Christov heat flux model.