Non-uniform Heat Source Research Articles

The influence of a non-uniform heat source/sink and Joule heating on the convective motion of a micropolar fluid in a chemically radiative MHD medium across a stretched sheet

The objective of the present exploration is to examine impactions of radiation, a non-uniform intensity source, and a permeable medium on a temperamental MHD blended convective micropolar liquid over an extended sheet subject to Joule heating. To transform the formulated problem into ordinary differential equations, the applicable similarity transformation is implemented. By utilizing R-K-F 4th -5th order approach with shooting method with MATLAB, the numerical solution is obtained. For the relevant profiles, the dimensionless parameters are visually displayed and described. Skin friction, the Nusselt number, and the Sherwood number have all been calculated using the answer found for the velocity, temperature, and concentration. With the assistance of line graphs, the impact of different flow factors being introduced into the problem is addressed. This research is conducted on the implications of MHD, porous, thermal radiation, viscous dissipation, Joule heating, non-liner thermal radiation and chemical reaction. For large values of micropolar parameter, the temperature is reduced and velocity and angular momentum distributions are raised. With the thermal radiation parameter, the temperature distribution gets better and thermal boundary layer is improved while the large values of Eckert number and non-uniform heat source or sink parameters, thermal boundary layer is improved. The higher thermal conductivity is proportional to the thickness of the thermal boundary layer. The concentration profile degrades with higher Schmidt number and chemical reaction parameter values. The current examination pertains to the significant subject matter of cooling of systems, artificial heart identification, oil-pipelined frictions, flow-tracers.

Influence of space conjugate temperature varying non-uniform heat sink/source on hydromagnetic slip water-EG (50:50) nanofluid

Significant cooling is an essential requirement in the field of aeronautical and bio-medical engineering, nuclear reactor system, solar collectors, and in development of electronic chips etc. Involving rotating conical geometries. In view of this, flow and heat transfer over conical geometries subject to different constraints of motion are highly needed. Implementation of magnetic field subject to flow pattern controls the fluid motion thereby imparting better cooling. Consideration of nanofluid instead of regular fluid yields prominent cooling of the associated surface. Such relevance has motivated the authors to work on magnetohydrodynamics and heat transfer investigation of water-EG (50:50) mixture based Al2O3 and Fe3O4 past heated and rotating down-pointing upright cone subject to impact of space and temperature varying non-uniform heat source or sink. Numerical solution of dimensionless governing equations is accomplished by implementing Runge-Kutta method. The findings indicate that swirl and axial velocities peter out with rise in magnetic parameter while both exhibit opposite impact in response to slip parameter. Temperature profiles upgrade due to amplification of space and temperature dependent parameters. Skin friction and heat transportation upsurge with growth of solid volume fraction of nanoparticle.

Computational simulation of Casson hybrid nanofluid flow with Rosseland approximation and uneven heat source/sink

This article candidly presents the magnetohydrodynamics Casson hybrid nanofluid flow over a stretching surface. In the present study, we added a nonuniform heat source or sink and non-linear thermal radiation. We considered Al2O3 and copper nanoparticles to have antibacterial and antiviral properties without any harmful impacts and used water as the host fluid. We simplified the governing flow equations by using suitable self-similarity variables, which are used to convert PDEs to ODEs. The mathematical equations are numerically solved by using the bvp5c technique in the MATLAB software. Additionally, with higher values of the magnetic field and Casson fluid parameters the velocity profile decreased. The temperature profile is enhanced by increasing the magnetic field and thermal radiation parameters. Increasing the Casson fluid and radiation parameters enhances the skin friction and Nusselt number profiles. Alumina nanoparticles find applications in cosmetic fillers, polishing materials, catalyst carriers, analytical reagents. Copper nanoparticles have high electrical conductivity, which has many uses in electrical circuits and biosensors.

Darcy-Forchheimer Flow of Casson Nanofluids Towards a Spinning Disk with Non-Uniform Heat Source

Darcy-Forchheimer Flow of Casson Nanofluids Towards a Spinning Disk with Non-Uniform Heat Source

Analysis of magneto-natural convection and second law of thermodynamics of Cu-Al2O3-hybrid nanofluid in a vertical wavy cabinet having a localized non-uniform heat source

Improvements in thermal transference rate and minimization of entropy generation are critical issues in many industrial and engineering applications where heat transfer coefficient is essential to achieve optimal performance and minimal energy consumption. In the present investigation, a computational analysis has been conducted to analyze the impact of magnetic field on magneto-free convection and entropy generation inside a vertical wavy cabinet filled by Cu-Al2O3/H2O hybrid nanosuspension. In the geometry of this model, vertical boundaries of the chamber are designed as wavy and kept as cooled temperature (Tc), whereas the horizontal boundaries are modeled as square and are designed to be thermally adiabatic, except the centrally heated portion on the bottom wall. The centered bottom heated section is supposed to be isothermal with linearly changing temperature, and it changes linearly from Th1 to Th2, whereas it is modelled as a non-isothermal condition. The main focus, in this investigation, is on the entire chamber filled with the combination of hybrid nanoparticles regarded the volumetric concentration of copper and alumina nanoparticles (Cu-50 %+Al2O3-50 %) along with base liquid (H2O). The transformed dimensionless partial differential equations were solved by using finite volume method (FVM) with power law differencing scheme. The simulated flow and temperature fields are scrutinized by streamlines, isotherms, entropy formations, total entropy generation and average convective Nusselt number associated with varying number of undulations (0 ≤ N≤3) volume fraction of hybrid nano liquid (0 ≤ φ ≤ 0.04) magnetic orientation angles (0° ≤ ς ≤ 135°), Hartmann number (Ha = 0 and 50), and dimensionless temperature drop (Ω = 0.001–0.1). From this study, it is found that the average Nusselt number and entropy generation increase as the solid volume fraction of hybrid nanoadditives increases, while opposite trend is observed when the values of Hartmann number rises. The findings show that growth of undulation number (N) causes the reduction of convective heat transfer rate as well as average entropy production intensity. The obtained outcomes concluded that hybrid nano liquid is more effective and finest choice for the improvement of cooling of heat transfer process and minimal energy loss than single nanoliquid. According to the new proposed criterion (TPC), the results show that square-shaped enclosure (N=0) manifests the better cooling performance among the considered governing parameters. The novelty of this study is to scrutinize the flat/ vertical wavy boundaries of the cabinet which can be represented as a model of heat transfer controller, in which it manages the thermal and flow field characteristics. Predominantly, the isothermal line source is used to boost the overall convective heat transfer which is applied in buildings and fluid-mounted heaters. Additionally, many investigators have focused only on the enhancement of heat transfer. As it is known, to increase the thermodynamic efficiency of a system, optimization of entropy generation is an excellent tool which reduces the loss of energy. Hence, it recently does a good engineering sense to highlight an entropy irreversibility.

Numerical analysis for Cattaneo-Christov heat flux on convective viscous non-Newtonian fluid flow through porous medium with nonuniform heat source

This work investigates the Ohmic heating, nonuniform heat generation, and Hall effects with Cattaneo-Christov model (CCM) on flow and heat transfer of power-low non-Newtonian fluids (NNFs) past stretching surface embedded in a porous medium. Runge-Kutta method is used to solve non-linear ODEs numerically using a shooting procedure. We study non-Newtonian fluids for power law values of 0.7 and 1.2, respectively. Innovation of this work lies in studying the effect of Hall currents in presence of buoyancy force and an irregular heat source on slip flow of NNFs moving through Darcy porous medium. Varying velocities, surface frictional forces, and Nusselt numbers are examined. Resulting entropy is also examined using computational flow problem investigation. Model-simulated results suggested that various factors play critical role in constructing thermal systems. It is asserted that Hall parameter, mixed convection parameter, Biot numbers, and thermal relaxation time improve heat transference rates by directly affecting fluid molecules temperature.

Convection and heat transfer analysis of Cu-water rotatory flow with non-uniform heat source

Convection and heat transfer analysis of Cu-water rotatory flow with non-uniform heat source

Enhancing Inductive IR Thermography by Using FFT-Equalization, Motion Tracking Detection and VDSR Super-resolution Processing

Among non-destructive inspection techniques, infrared thermography stands out as a promising technology that enables real-time inspection of large areas without the need for physical contact. In this study, we employed the dynamic induction thermography method, which is one of the active infrared thermography techniques, to detect defects on the back side of the S275 material specimen. This technique involves creating relative movement between the IR camera and the specimen. We acquired sequence images at different moving speeds using the induction thermography technique, and then used the FFT with Gaussian filtering to solve for non-uniform heat sources. To further enhance the resolution, we applied the VDSR technique, which is based on deep neural networks. The effectiveness of this approach was validated both qualitatively and quantitatively. Finally, we utilized the MOT algorithm to automatically detect defects in the image with the highest thermal contrast, which was captured at a speed of 15 mm/s. In this study, we demonstrate the effectiveness of thermal equalization using the GF-based FFT algorithm, as well as the superresolution conversion achieved through the VDSR-based deep neural network. Additionally, we present a mechanism for automated slit detection using the MOT algorithm.

Convection driven by a nonuniform radiative internal heat source in a cavity: Example of medical isotope production in liquid targets

In the present study we use two-dimensional direct numerical simulations (DNS) to understand the coupled heat transfer to fluid flow in a liquid target for the production of nuclear medicines. Fluid motion is driven by buoyancy created by heat generated by a proton beam. The internal heat source has a gaussian distribution in the vertical direction and a rapidly growing intensity in the horizontal direction until it reaches a range at the Bragg peak where the heating drops to zero. The structure of the heating imposes two convective cells, separated at the location of the range. We solve the governing fluid flow and energy equations in a square cavity subject to highly nonuniform internal heating generated by the energy deposition of a proton beam. While most studies of convection driven by an internal heat source in a fluid layer have been focused on a uniform heating of the fluid, our study shows that the nonuniformity in the heat source has important implications for the temperature and flow fields, the boundary heat fluxes, and the growth of convective instabilities in the flow. Interestingly, the scalings of the maximum and averaged temperatures with the Rayleigh number compare similarly to previously found power laws for uniformly heated fluid layers. At higher power levels, the layer of fluid near the top cold boundary becomes convectively unstable via Rayleigh–Taylor instabilities. By comparing the rate of growth of these instabilities to their rate of advection to the boundaries of the cavity, a model is developed that predicts the instability of the convective cells for different values of the range of the beam and the Rayleigh number. Crucially, we demonstrate that the disturbances in the production of isotopes due to convective instabilities and the design of the cooling system is dependent on the location of the Bragg peak and must be considered in design of future generation of this class of target.

Computational investigation of methanol-based hybrid nanofluid flow over a stretching cylinder with Cattaneo–Christov heat flux

Abstract This study investigates heat transfer rates in (AA7075-AA7072/Methanol) hybrid nanofluid flows, considering non-uniform heat sources and Cattaneo–Christov heat flux, with significant implications for aerospace engineering by enhancing thermal management in aircraft engines. The findings could revolutionize automotive cooling system efficiency, optimize heat dissipation in electronic devices, and advance the design of renewable energy systems such as concentrated solar power plants. The study aims to conduct a comparative analysis of (AA7075/Methanol) nanofluid and (AA7075-AA7072/Methanol) hybrid nanofluid flow, examining heat transfer rates, non-uniform heat sources, and Cattaneo–Christov heat flux theory around a stretching cylinder. Thermal radiation and the Biot number are also evaluated. Two different nanoparticles, AA7072 and AA7075, are used with methanol to create AA7075/Methanol nanofluid and AA7075-AA7072/Methanol hybrid nanofluid. The study compresses the resultant non-linear partial differential equation system and applies suitable similarity transformations to reduce the governing partial differential equations with boundary conditions to dimensionless form. The BVP4C shooting method in MATLAB is employed to numerically and graphically solve these dimensionless ordinary differential equations. The results indicate that higher curvature parameter values correlate with increased velocity and temperature distribution profiles. A rise in nanoparticle volume fraction reduces the radial velocity profile but increases the temperature profile. Temperature distribution profiles increase with higher thermal radiation parameter and Biot number values, while higher thermal relaxation parameter values decrease temperature. Additionally, thermal distribution profiles rise with increasing values of both the time-dependent heat source constant and space-dependent heat source parameter.

Study of the time dependent MHD convective couple stress nanofluid flow across bidirectional periodically stretched frame using the homotopy analysis method

AbstractThe current study presents a time dependent couple stress nanofluid flow across a bidirectional periodically stretched surface under magnetic effects. The effects of nonuniform heat source and variable thermal conductivity on the convective heat transfer are analyzed. The effect of the chemical reaction, nonlinear mixed convection, and activation energy are also considered. Adequate dimensional quantities are utilized to entertained the problem in simplified from. Then, a series of solutions are obtained via homotopic analysis method. Tables and graphs are organized to evaluates the physical dynamic of problem. The archived observations convey that the nonlinear convective parameters cause a rise in horizontal velocity component. It is determined that flow intensity and skin friction have an increasing behavior with most of the governing parameters. Current investigation emphasized that the temperature increases by imposing variable thermal conductivity. The concentration values become higher by increasing the activation energy but decrease with the reaction rate.

Inverse heat transfer problem for the characterization of nanofluids produced with different types of palladium nanoparticles

The objective of this work is the measurement of physical properties of distilled water nanofluids containing palladium nanocubes, palladium cerium oxide nanoparticles, and their respective hydrides. Due to their biocompatibility and favorable photothermal effects, palladium nanoparticles can be used to promote localized absorption of external energy sources in the thermal treatment of cancer, aiming at a thermal damage constrained to the tumor region without significant effects to the healthy tissues. An inverse problem is solved here within the Bayesian framework of statistics with the Markov Chain Monte Carlo method, by using nonintrusive transient measurements taken with an infrared camera during the heating of different water-based nanofluids. The mathematical model used in this work takes into account natural convection effects, due to the nonuniform heat source caused by the diode-laser that heats the nanofluids. Prior distributions for the model parameters were selected based on additional independent measurements, theoretical models and by the careful implementation of the experiments. The proposed model and the estimated parameters were validated, with an excellent agreement between the measured temperatures and those obtained from stochastic simulations during the solution of the inverse problem.

On the dual diffusion flow of Powell–Eyring hybrid nanofluid with motile microorganism and non-uniform heat source using Darcy–Forchheimer model

This communication elaborates the rheological behavior of bioconvection flow of Powell–Eyring hybrid nanofluid over a stretchable heated cylinder embedded in Darcy–Forchheimer porous medium. The single and two-phase nanofluid models are used as mixture model by taking volumetric friction and dual diffusion of injected nanomaterial’s, while the Buongiorno model takes the dual diffusion of nanomaterials, allowing us to evaluate the thermophoresis and Brownian diffusion properties. The governing equations are solved with an efficient Runge–Kutta–Fehlberg numerical technique. The effects of appropriate parameters on flow, temperature, concentration, and motile microorganism. Our findings reveal that the fluid velocity increases with curvature parameter, while detract with Darcy and porosity parameter. Temperature is increasing function of Brownian, thermophoresis and heat source parameters. The concentration and motile profile increases with curvature parameter. An escalating trend for energy and mass transport was seen against curvature and thermophoresis parameter. Higher values of Curvature and Schmidt number depict positive impact on nanoparticle concentration, while the results for chemical reaction are conflicting. An increasing value of Brownian and thermophoresis parameters promote higher temperature. The temperature and thermal boundary layer thickness are also affected by the heat source and sink parameters in opposite manner.

Numerical simulation for the slip impacts on the radiative nanofluid flow over a stretched surface with nonuniform heat generation and viscous dissipation

Abstract The growing fascination with nanofluid flow is motivated by its potential applications in a variety of industries. Therefore, the objective of this research article is to conduct a numerical simulation of the Darcy porous medium flow of Newtonian nanofluids over a vertically permeable stretched surface, considering magnetohydrodynamic mixed convection. Various attributes, such as the impacts of slip, thermal radiation, viscous dissipation, and nonuniform heat sources, are integrated to explore the behavior of the flow. The utilization of the boundary layer theory helps to describe the physical problem as a system of partial differential equations (PDEs). These derived PDEs are then converted to a system of ordinary differential equations (ODEs) through the application of suitable conversions. The outcomes are obtained using the finite difference method, and the effects of parameters on nanofluid flow are compared and visualized through both tabular and graphical representations. The outcomes have been computed and subjected to a comparative analysis with previously published research, revealing a remarkable degree of agreement and consistency. Consequently, these innovative discoveries in heat transfer could prove beneficial in addressing energy storage challenges within the contemporary technological landscape. The noteworthy main findings indicate that when the porous parameter, magnetic number, velocity slip parameter, viscosity parameter, and Brownian motion parameter are assigned higher values, there is an observable expansion in the temperature field. Due to these discoveries, we can enhance the management of temperature in diverse settings by effectively modulating the heat flow.

Two-phase numerical simulation of thermal and solutal transport exploration of a non-Newtonian nanomaterial flow past a stretching surface with chemical reaction

Abstract Non-uniform heat sources and sinks are used to control the temperature of the reaction and ensure that it proceeds at the desired rate. It is worldwide in nature and may be found in all engineering applications such as nuclear reactors, electronic devices, chemical reactors, etc. In food processing, heat is used to cook such as microwave ovens, pasteurize infrared heaters, and sterilize food products. Non-uniform heat sources are mainly used in biomedical applications, such as hyperthermia cancer treatment, to target and kill cancer cells. Because of its ubiquitous nature, the idea is taken as our subject of study. Heat and species transfer analysis of a non-Newtonian fluid flow model under magnetic effects past an extensible moving sheet is modelled and examined. Homogeneous chemical reaction inside the fluid medium is also investigated. This natural phenomenon is framed as a set of Prandtl boundary layer equations under the assumed convective surface boundary constraint. Self-similarity transformation is employed to convert framed boundary layer equations to ordinary differential equations. The resultant system is solved using the efficient finite difference utilized Keller box method with the help of MATLAB programming. The influence of various fluid-affecting parameters on fluid momentum, energy, species diffusion and wall drag, heat, and mass transfer coefficients is studied. Accelerating the Weissenberg number decelerates the fluid velocity. The temperature of the fluid rises due to variations in the non-uniform heat source and sink parameters. Ohmic dissipation affects the temperature profile significantly. Species diffusion reduces when thermophoresis parameter and non-uniform heat source and sink parameters vary. The Eckert number enhances the heat and diffusion transfer rate. Increasing the chemical reaction parameter decreases the shear wall stress and energy transmission rate while improving the diffusion rate. The wall drag coefficient and Sherwood number decrease as the thermophoretic parameter increases whereas the Nusselt number increases. We hope that this work will act as a reference for future scholars who will have to deal with urgent problems related to industrial and technical enclosures.

Entropy generation and heat transport performance of a partially ionized viscoelastic tri-hybrid nanofluid flow over a convectively heated cylinder

A wide range of industrial applications where effective heat transport, fluid dynamics, and material adaptability are vital and can be addressed by the deployment of ternary hybrid nanofluids across an extensible cylinder. This work deals with entropy optimized flow and heat transport features of partially ionized and magnetically affected Prandtl fluid loaded with three nanomaterials drifting over a convectively heated cylinder. Three distinct nanomaterials (Al2O3,CuO,TiO2) are dispersed in order to enhance the heat performance rate of functional fluid. The ion and Hall slip effects, Joule heating, non-uniform heat source, and frictional heating are among the initial hypotheses in this computational analysis. The problem is presented quantitatively by taking the Tiwari-Das model to the basic equations. The Keller-Box framework is used to solve the nonlinear equations computationally. The findings reveal that enhancement in the Hall and ion slip effects diminish a rapid growth in entropy, while an opposite trend emerges for the Brinkman and magnetic parameter. The fluid motion is depressed by magnetic field intensity. The flow field and thermal transfer rate are enhanced by uplifting Prandtl first and curvature parameters. The system's irreversibility detracts with Brinkman number. A higher curvature parameter β results an elevated shear stresses and skin friction.

Influence of periodicity on natural convection in a square porous cavity due to non-uniform heat under LTNE state

In this article, the influence of the local thermal non-equilibrium (LTNE) state on free convection in a square cavity filled with fluid-saturated porous medium is investigated numerically. The steady-state flow is induced due to sinusoidal heat distributed on the side walls of the cavity and insulated of the horizontal walls. The coupled flow governing equations are solved numerically by using the finite volume method (FVM) consisting of the SIMPLER (Semi-Implicit Method for Pressure Linked Equation Revised) Algorithm. The numerical simulations of temperature and stream-function contours are carried out for the non-Darcy model. The developed code is validated with existing numerical and present computed results for the case of a square enclosure associated with non-uniform heat source. Then, the present numerical results are analyzed over a range of physical parameters, like periodicity parameter ( N ≥ 1 ), interface heat transfer coefficient ( 10 − 2 ≤ H ≤ 10 2 ), porosity scaled thermal conductivity ratio ( 10 − 2 ≤ γ ≤ 10 2 ), with a fixed Rayleigh number ( Ra = 10 6 ), Darcy number ( Da = 10 − 4 ), Prandtl number (Pr = 0.71), and porosity ( ε = 0.8 ). To study the impacts of these key parameters on the fluid flow behavior and isotherm patterns of fluid as well as solid phase in the porous-square enclosure. From present numerical experiments that the structure of flow is controlled by multicellular structure with rotating clockwise and anticlockwise directions in the entire results. The flow dynamics are highly affected by the periodicity parameter (N) under LTNE circumstances. The characteristics of the local Nusselt number have the point of inflection and the maximum magnitude of it increases with N. The significant effect of H is found on the heat transfer rate of fluid phase but it is negligible on the heat transfer rate of solid phase. However, the influence of γ is found reverse in nature on the heat transfer rate of fluid as well as solid phase when as compared to the effect of H.

Gyrotactic Mixed Bioconvective Flow of Copper–Water Nanofluid Past a Rotating Cone with Non-uniform Heat Source and Activation Energy

Gyrotactic Mixed Bioconvective Flow of Copper–Water Nanofluid Past a Rotating Cone with Non-uniform Heat Source and Activation Energy

Destabilization of geodesic acoustic-like mode in the presence of poloidally inhomogeneous heat sources in tokamak plasmas

The effects of poloidally inhomogeneous heat sources are investigated through a gyrokinetic formula in collisionless toroidal plasmas. A gyrokinetic dispersion relation is newly derived under the assumption that equilibrium parallel heat flows are generated to remove the injected poloidally nonuniform heat source. The dispersion relation is numerically solved, considering both inboard and outboard heat source injections. In the case of the inboard source injection, both Stringer spin-up and geodesic acoustic mode (GAM) are excited. Conversely, outboard injection leads to the emergence of a heat source-driven GAM (referred to as Q-GAM), featuring a frequency around half that of the standard GAM. Various physical quantities of the Q-GAM, such as mode frequency and source threshold, are analyzed through parametric scans. The Q-GAM exhibits similarities with the energetic-particle-driven GAM (EGAM), particularly in its frequency range, and both belong to one of the strong Landau damped poles. Despite having distinct driving mechanisms and structural differences in parallel velocity and poloidal coordinates, the response function of the perturbed parallel pressure to the potential, mainly contributing to the destabilization of each mode around half of the GAM frequency, is derived to have a similar form for both the Q-GAM and EGAM cases.

Radiative bioconvective flow with non-uniform heat source and Soret and Dufour impacts

Background and objectiveThe stretched flow with heat transfer has pivotal role in geothermal energy system, oil extraction, continuous casting, metal spinning and electronic cooling. Owing to this fact, the current analysis focuses on non-linear thermal radiation effect in bio-convective stagnation point flow by a stretchable wedge. Darcy relation is used to discuss the porous space. Convective conditions are deliberated. Non-uniform heat source is addressed. Soret and Dufour outcomes are analyzed. Dissipation and magnetohydrodynamics are discussed. Presence of gyrotactic microorganisms along with chemical reaction is considered. MethodologyRelated non-linear partial differential equations (PDEs) are reduced into dimensionless ordinary differential equations (ODEs) through adequate transformations. Optimal homotopy analysis method (OHAM) is adopted for the computations of related nonlinear differential systems. ResultsFlow, microorganism field, concentration and temperature distribution are graphically explored. Numerical analysis for coefficient of skin friction, microorganism density number and Sherwood and Nusselt numbers against emerging parameters are discussed. It is noted that velocity and skin friction coefficient have similar scenario for modified Hartman number. Thermal transport rate and temperature have reverse trends for non-uniform heat source variable. An augmentation in thermal distribution is seen through thermal Biot number. Larger Dufour number has increasing trend for temperature. An increasing trend for solutal Biot number for concentration is noticed. Larger Soret number leads to concentration enhancement. Microorganism field and motile density number against Peclet number have opposite response. There is reduction for bio-convective Lewis number in motile density number.