Effect Of Heat Generation Research Articles

Entropy generation in a chemically and thermally reinforced doubly stratified porous enclosure in a magnetic field

In this article, the study of chemical reaction and heat generation effects on the magnetohydrodynamic free convection in the thermal and mass stratified fluid-filled porous enclosure under the influence of cross-diffusion forces is extended to the entropy generation analysis for the design of relevant tools of engineering applications. Here, the multiphysics associated with natural convection in doubly stratified fluid containing chemically reactive square porous enclosure under uniform magnetic field furnishes novel flow dynamics modeling. Since the distinctive nature of the free convective flow mechanism is described by the complex heat and mass transfer process, the thermal investigation cannot be considered complete until the visual illustration of the transportation of heat and mass flux is provided. Therefore, the new heat flux and mass flux models are proposed for the multi-force effect on chemically reactive porous media under the effect of viscous dissipative heat generation to facilitate the directional manifestation of heat and mass flux transitions along with intensity. Additionally, the thermodynamical measures are established by the new entropy generation model and advanced Bejan number irreversibility characterization.

Effect of Temperature and Heat Generation on Martensitic Phase Transformation in DH Steels

Effect of Temperature and Heat Generation on Martensitic Phase Transformation in DH Steels

Predication of temperature distribution and strain during FSW of dissimilar Aluminum alloys using Deform 3D

Dissimilar aluminium alloy plates AA6061 and AA5052 were subjected to friction stir welding (FSW) in order to examine the effect of heat generation on the welding process. Thermocouples were used to measure the temperature distribution on the workpiece during welding and it was found that the advancing side had higher temperatures than the receding side. The FSW process was simulated at tool speeds of 1000, 1200, and 1400 rpm, as well as feed rates of 20, 40, and 60 mm/min. The tests were designed using the Taguchi OA. AA6061 identical welds show a small reduction in grain size at the HAZ, but AA5052 and AA6061 dissimilar welds show much larger grain sizes at the weldment than the base metal. While keeping a consistent feed rate, the tool speed was found to boost weld zone heat generation. It is possible to reduce the amount of heat generated in weld zones by increasing the feed rate while maintaining consistent tool rotation rates. Analysis of variance (ANOVA) demonstrated that the advancing side, retreating side as D1F3S1, and total heat generation is D1F3S3 (i.e., distance from the welded zone is 20 mm, feed rate at 60 mm/min, and tool speed at 1000 rpm) is the ideal temperature distribution and heat generation condition. For FSW, Deform-3D software was used to create a model of the workpiece and tool. Thermal analysis was performed to determine the temperature distribution throughout each part of the workpiece.

Effects of Heat Generation/Absorption on Magnetohydrodynamics Flow Over a Vertical Plate with Convective Boundary Condition

Heat generation effect in a steady two-dimensional magnetohydrodynamics (MHD) flow over a moving vertical plate with a medium porosity has been studied. By similarity transformation variables, the coupled non-linear ordinary differential equations describing the model are obtained. The resulting equation is then solved, using Galerkin Weighted Residual Method (GWRM), where the effect of heat generation, Magnetic Parameter as well as other physical parameters encountered were examined and discussed. Some of the major findings were that increase in heat generation and convective heat parameter enhances the plate surface temperature as well as temperature field which allows the thermal effect to penetrate deeper into the quiescent fluid.

Irreversibility analysis for nanofluid (NiZnFe2O4-C8H18 and MnZnFe2O4-C8H18) flow with radiation effect

Here we simulate heat transfer analysis for radiative flow of nanomaterials by a curved stretched sheet. Radiation, heat generation and dissipation effects are addressed in heat expression. Nickel zinc ferrite (NiZnFe2O4) and manganese zinc ferrite (MnZnFe2O4) are used as the nanoparticles and engine oil (C8H18) as a base liquid. Irreversibility analysis modeling is developed through thermodynamics second law. Entropy generation reduction guarantees the improvement of thermal system performance. Nonlinear differential system is reduced to an ordinary one through suitable transformation. The given system is solved through ND-solve method. Velocity, pressure, temperature, entropy rate and Bejan number variations against different influential variables are scrutinized graphically for both NiZnFe2O4 and MnZnFe2O4 nanoparticles. Performance of sundry parameters on Nusselt number and velocity gradient are analyzed for both NiZnFe2O4 and MnZnFe2O4 nanoparticles. An improvement in velocity field is noted for curvature variable. An improvement in radiation rises temperature. For higher values of volume fraction variable both thermal and velocity fields are augmented. Radiation variable leads to improve the entropy generation and temperature for both nanoparticles. An increment in temperature is seen against Eckert number. Bejan number is reduced versus volume fraction. Velocity gradient is enhanced for curvature variable. An increment in Nusselt number is found is noticed via volume fraction.

Magnetohydrodynamic Flow Past a Nonlinear Stretching or Shrinking Cylinder in Nanofluid with Viscous Dissipation and Heat Generation Effect

The Tiwari-Das model is used to investigate magnetohydrodynamic stagnation point flow and heat transfer past a nonlinear stretching or shrinking cylinder in nanofluid with viscous dissipation and heat generation using. The partial differential equations, also known as governing equations, were reduced to nonlinear ordinary differential equations using similarity transformation. MATLAB with the bvp4c solver is used for numerical computing. The controlling parameter, such as nanoparticle volume fraction, magnetic, curvature, nonlinear, radiation, and heat generation parameters, as well as Eckert and Grashof numbers, influence the skin friction coefficient, heat transfer rate, velocity, and temperature profiles. The results are presented as graphs to show the influence of the variables studied. In some circumstances of stretching and shrinking cases, dual solutions can be obtained.

Numerical study of hybrid nanofluid flow and heat transfer on a stretching sheet with MHD and heat generation effects

AbstractThe key goals of this manuscript are (i) to investigate the heat transfer and unsteady flow properties of a viscous hybrid nanofluid on a stretching sheet having nonzero slot velocity, and (ii) to examine the impacts of magnetic field parameter, stretching parameter, nanoparticle volume fraction, and heat generation parameter on the Nusselt number and skin friction coefficient numerically. The Tiwari‐Das nanofluid model is used. The mathematical (PDEs) equations controlling border layer flow and heat transfer are resolved by applying a numerical finite‐difference technique in the Crank Nicolson style. For the validation process, the analytical solution is established using the Laplace transform technique and is compared with the numerical solution for a particular case and found to be in superb agreement.

Wear Based Lifetime Estimation of a Clutch Facing using Coupled Field Analysis

Repetitive use of the clutch, over a period of time, causes the friction material at the contact surfaces (clutch facing and flywheel/pressure plate) to wear, thus deteriorating its performance and usable life. The working life of a rigid clutch is the limiting factor when it comes to extracting maximum performance from a dual mass flywheel system, which is used in a lot of modern vehicles nowadays to lower fuel consumption and improve ride quality. In this study, we investigate the influence of different groove patterns on wear in rigid clutch facings and estimate their life using a comprehensive finite element model. The wear is calculated and analysed for five different groove patterns across two different inorganic materials, namely FTL180 and TF1600-MC2, using Archard’s Adhesive Wear Model. Coupled multi-physics elements are employed in the analysis to capture the effect of frictional heat generation on wear. We found that the Waffle pattern offered a decrease of 10.4% in volumetric wear loss, a 5.78% decrease in maximum wear thickness and an increase of 11.51% in the average working life is used in city like conditions with frequent engagements. This work sheds light on the impact of groove patterns on clutch facing wear and opens a new path for the design and development of more resilient rigid clutches.

Impact of Joule heating and multiple slips on a Maxwell nanofluid flow past a slendering surface

This manuscript presents a study of three-dimensional magnetohydrodynamic Maxwell nanofluid flow across a slendering stretched surface with Joule heating. The impact of binary chemical reactions, heat generation, thermal radiation, and thermophoretic effect is also taken into consideration. The multiple slip boundary conditions are utilized at the boundary of the surface. The appropriate similarity variable is used to transfer the flow modeled equations into ODEs, which are numerically solved by the utilization of the MATLAB bvp4c algorithm. The involved parameter’s impact on the concentration, velocity, and temperature distribution are scrutinized with graphs. The transport rates (mass, heat) are also investigated using the same variables, with the results reported in tabulated form. It is seen that the fluid relaxation, magnetic, and wall thickness characteristics diminish the velocities of fluid. Further, the velocity, concentration, and temperature slip parameters reduce the velocities of fluid, temperature, and concentration distribution. The results are compared to existing studies and shown to be in dependable agreement.

Temperature and strain distribution during friction stir welding of AA6061 and AA5052 aluminum alloy using deform 3D

This study investigated the effect of heat generation during friction stir welding (FSW) on dissimilar aluminium alloy plates AA6061 and AA5052 using process variables such as tool rotational speed, feed rate and temperature distribution. Temperature distributions on the workpiece were recorded at advancing side and receding side during welding by using thermocouples and revealed that temperatures on the advancing side are greater than those on the receding side. The FSW process was simulated at the tool speed of 1000, 1200 and 1400 rpm, feed rate of 20, 40, 60 mm/min. A Taguchi OA has been used for designed the experiments. The findings of the micro hardness test at the welded zone analysed using Vickers’s tester. Microstructure analysis of AA6061 identical welds reveals that grains are slightly reduced at HAZ, while analysis of AA5052 and AA6061 dissimilar welds reveals that grain are significantly enlarged at weldment than base metal. It also found that, the tool speed increases while maintaining a steady feed rate, increased the amount of heat generated in weld zones. On the other hand, increasing feed rate while maintaining constant tool rotational speeds results in a decrease in the amount of heat created in weld zones. Analysis of variance (ANOVA) revealed, the optimal condition of temperature distribution and heat generation is T3F1 (i.e., tool speed of 1400 rpm and feed rate of 20 mm/min). A model of the workpiece and tool was developed using Deform-3D Software for friction stir welding, and thermal analysis was performed to analyse the temperature distribution.

Non-Newtonian Cross fluid flow through a porous medium with regard to the effect of chemical reaction and thermal stratification phenomenon

A comprehensive study encompassing a general development and a presentation of results for the influence of the chemical reaction on the laminar Cross fluid flow and heat mass transfer is made here. The motion of the fluid is assumed due to the stratified stretching sheet which embedded in a porous medium. Some of important characteristics of the fluid such as the variable thermal conductivity and its dependence on the temperature field are mentioned. Accordingly, some account of the possible effects of heat generation on heat mass transfer in fluid flows is given. Numerical treatments have been introduced for the resulting coupled ordinary differential equations. Then, the results of the variation in the velocity profile, the temperature profile and the concentration profile due to porous parameter, thermal conductivity parameter, heat generation parameter, thermal stratification parameter and chemical reaction parameter are presented graphically. At the proposed physical conditions for the problem, the Sherwood number, the Nusselt number or the temperature gradient and the local skin friction coefficient were measured. It is interesting to observe that, both the solutal and the thermal stratification phenomena plays a dominant role in the mechanism of heat and mass transfer. Also, regarding the warming factors within the thermal boundary layer, both Darcy parameter and heat generation parameter have been proposed which are of special interest in heat transfer problems. Finally, the results pointed out the efficiency of the proposed numerical method, where it gives a good representation describing the mechanism of the flow, heat and mass transfer.

The experimental study on a novel integrated system with thermal management and rapid cooling for battery pack based on C6F12O spray cooling in a closed-loop

Amongst the background of the popularization of the lithium-ion battery (LIB), the thermal issues have attracted a significant amount of attention. In the present paper, a novel integrated system is proposed with thermal management and rapid cooling based on C 6 F 12 O spray cooling in a closed loop. Through experiments using a 4 × 4 dummy 18650 cylindrical battery pack, the cooling performance of the battery thermal management system (BTMS) based on the C 6 F 12 O spray cooling is demonstrated to be effective. Further, the controllable heat generation benefits for the analysis of heat dissipation mechanisms. For the condition of 6 cm spray height with 2.05 g/s flow rate, the heat is taken away by the liquid film accounted for around 30% of the total heat dissipation, while that of direct spray cooling accounted for around 70%. In the rapid cooling experiment, compared with the blank experiment, the thermal runaway maximum temperature significantly decreased by 517.1 °C and the thermal runaway of the first battery is delayed by 229 s. Owing to the significantly effective heat removal ability of C 6 F 12 O spray cooling, the propagation of the thermal runaway is cut off. • A novel integrated system with thermal management and rapid cooling is proposed. • The effects of spray height, flow rate, and heat generation are explored. • The effectiveness of the proposed management system is proved experimentally. • The propagation of thermal runaway is cut off with the application of spray cooling.

Influence of Al203 particle mixed dielectric fluid on machining performance of Ti6Al4V

In this research work, an attempt was made to machine Ti6Al4V titanium alloy utilizing AA6061/10 Gr composite tool. The composite tool was fabricated using stir casting technique and Al2O3 particles of size 5 μm were incorporated in the dielectric fluid to enhance the machining performance. Experiments were conducted by varying Al203 concentration, pulse on time, current, and pulse off time, and the responses Material Removal Rate (MRR), Tool Wear Rate (TWR), and Surface Roughness (Ra) were recorded. Experiments runs were planned using Taguchi orthogonal array. The results revealed that adding powder increases MRR and TWR owing to the excessive heat generation and bridging effect respectively. The best surface finish was attained due to the increase in spark gap and complete flushing of machined debris. Coating of materials over the machined specimen was observed when the parametric value of Ton was higher than 60 μs under PMEDM conditions. Pits, craters and cracks were observed on the machined topography which was eliminated when 5 g l−1 of Al2O3 particles were added to dielectric fluid. MEIOT technique was utilized for optimization and it was observed that Ton 15 μs, Toff 4 μs and current 7 A and powder concentration of 10 g l−1 results in best machining performance.

Time fractional model of electro-osmotic Brinkman-type nanofluid with heat generation and chemical reaction effects: application in cleansing of contaminated water

Drilling fluids execute a dominant role in the extraction of oil and gas from the land and rocks. To enhance the efficiency of drilling fluid, clay nanoparticulate has been utilized. The inclusion of clay nanomaterial to drilling fluids significantly elevate their viscosity and thermal conductivity. Therefore, the present investigation is focused on the analysis of time-fractional free convective electro-osmotic flow of Brinkman-type drilling nanofluid with clay nanoparticles. The heat generation and chemical reaction characteristics and influence of the transverse magnetic field have also been taken into an account. The local mathematical model is formulated in terms of coupled PDEs along with appropriate physical conditions. The dimensional governing equations have been non-dimensionalized by using relative similarity variables to encounter the units and reduce the variables. Further, the non-dimensional local model has been artificially converted to a generalized model by utilizing the definition of time-fractional Caputo–Fabrizio derivative with the exponential kernel. The graphical results are analyzed via computational software Mathematica, to study the flow behavior against inserted parameters. From graphical analysis it has been observed qualitatively that the velocity field has been raised against the greater magnitude of electro-osmosis parameter Es. Numerical table for Nusselt number is calculated from the obtained exact solutions. From the analysis 11.83% elevation in the rate of energy transition of drilling nanofluid has been reported in response of clay nanoparticles.

Numerical Solutions for Laminar Boundary Layer Nanofluid Flow along with a Moving Cylinder with Heat Generation, Thermal Radiation, and Slip Parameter

The investigation of the numerical solution of the laminar boundary layer flow along with a moving cylinder with heat generation, thermal radiation, and surface slip effect is carried out. The fluid mathematical model developed from the Navier-Stokes equations resulted in a system of partial differential equations which were then solved by the multidomain bivariate spectral quasilinearization method (MD-BSQLM). The results show that increasing the velocity slip factor results in an enhanced increase in velocity and temperature profiles. Increasing the heat generation parameter increases temperature profiles; increasing the radiation parameter and the Eckert numbers both increase the temperature profiles. The concentration profiles decrease with increasing radial coordinate. Increasing the Brownian motion and the thermophoresis parameter both destabilizes the concentration profiles. Increasing the Schmidt number reduces temperature profiles. The effect of increasing selected parameters: the velocity slip, Brownian motion, and the radiation parameter on all residual errors show that these errors do not deteriorate. This shows that the MD-BSQLM is very accurate and robust. The method was compared with similar results in the literature and was found to be in excellent agreement.

Non-similar aspects of heat generation in bioconvection from flat surface subjected to chemically reactive stagnation point flow of Oldroyd-B fluid

In recent years, utilization of nano-technology in drugs and cancer growth treatment has produced a great deal of temptation in thermal properties of biological nanofluid, for example, blood with nanoparticles suspension. The objective of this research is to discover a MHD naturally bio-convective flow of non-Newtonian bio-nano-fluid containing blood as base fluid with (Al2O3) alumina nanoparticles suspension carrying effect of buoyancy, chemical reaction, moving microorganism and heat generation near stagnation region. The Buongiorno along Tiwari and Das nanofluid model is employed whereas Oldroyd-B model is capitalized for depicting the viscoelastic behavior of blood. The non-similarity transformations are exercised on governing nonlinear partial differential system (PDE’s) to transform them into system of non-dimensional PDE’s. After applying appropriate transformations the local non-similarity method via bvp4c algorithm is adopted to numerically deal with the problem. The significance of parameters such as Grashof numbers, magnetic field, Brownian motion, thermophoresis, Deborah numbers, Prandtl number, Schmidt number, Peclet number, heat generation/absorption number and chemical reaction on velocity, temperature, concentration and density of moving microorganism are computed in the graphical profiles to explain the physical state of problem. Physical quantities i.e. local Nusselt number, local Sherwood number and local microorganism density number are also calculated.

Hybrid nanofluid flow over two different geometries with Cattaneo–Christov heat flux model and heat generation: A model with correlation coefficient and probable error

The authors scrutinize the steady, MHD flow of SiO2−MoS2/water hybrid nanofluid towards two different geometries i.e. a wedge and a cone. The Tiwari and Das model is implemented with a generalized–Fourier's model, popularized as Cattaneo-Christov heat flux model. Analysis of heat transfer also incorporates the effects of suction, heat generation and thermal radiation. To showcase the relationship between engineering quantities and pertinent parameters involved in the study, the correlation coefficient for heat transfer coefficient and the skin friction coefficient is computed followed by the computation of probable error and statistical declaration. Similarity transformations are utilized to remodel the constitutive laws of flow in non-dimensional form. Numerical computation of non-linear, coupled O.D.E.’s is performed with the support of the Runge-Kutta-Fehlberg scheme and shooting method. Graphical and tabular illustrations of computed results are provided to report the variation in flow properties with the fluctuation in physical parameters. In both cases, i.e. flow close to a wedge and a cone, the temperature of hybrid nanofluid enhances on intensifying the thermal radiation and experiences a decrement with thermal relaxation parameter and magnetic field. Rising values of the suction parameter, thermal relaxation parameter, and thermal radiation cause increment in heat transfer coefficient. Interestingly, it was spotted that the heat generation parameter has contrary effects on temperature distribution over the two geometries.

Thermal features and heat transfer enhancement of a Casson fluid across a porous stretching/shrinking sheet: Analysis of dual solutions

This article explores an unsteady radiative two-dimentional stagnation point flow of a Casson fluid along a stretching and shrinking sheet which is depending on the mixed convection, convective condition, and the slip condition. Additionally, the effect of heat generation and Joule heating is deemed. This study formulates the nonlinear Partial Differential Equations (PDEs), that are initially transformed into the non-dimensional Ordinary Differential Equations (ODEs) based on the dimensionless variables. The bvp4c function in MATLAB has been employed to find the dual solutions for the dimensionless ODEs. These solutions have been determined with regards to the fluid velocity, skin friction coefficient, temperature, and the local Nusselt number which have been found under the influence of the related fluid parameters. It has been found that the friction drags respectively enhances and declines in the stable and unstable flows caused by rising values of Casson parameter, mixed convection, and slip parameter. The heat transfer rate respectively improves with the improvement of radiation, Biot number and Prandtl number although it declines with the improvement of heat generation parameter. According to our deep knowledge, the outcomes of the existing effort are innovative and had not been previously evaluated by someone. Our work can produce a paradigm considering forthcoming analyses of non-Newtonian fluids.

Viscous Dissipation Effect in the Free Convection of Non-Newtonian Fluid with Heat Generation or Absorption Effect on the Vertical Wavy Surface

The present article analyzes the effect of viscous dissipations on natural convection heat transfer. The power law model for non-Newtonian fluid with heat generation or absorption effect along a sinusoidal wavy surface with isothermal boundary condition is investigated. A simple coordinate transform is employed to map the wavy surface into a flat surface, and also, the fully implicit finite difference method is incorporated for the numerical solution. The findings of this study can help better understand the effect of parameters such as the Brinkman number, heat generation/absorption, wave amplitude magnitude, and generalized Prandtl number on convective heat transfer in dilatant and pseudoplastic non-Newtonian. Results show that as the Brinkman number increases, the amount of heat transfer decreases. This is physically justifiable considering that the fluid becomes warmer due to the viscous dissipation, decreasing its temperature difference with the constant temperature surface. Also, the effect of the power law viscosity index is surveyed. It is demonstrated that the magnitude of the local Nusselt number in the plane leading edge has the smallest quantity for pseudoplastic fluids compared to dilatant Newtonian fluids. Additionally, as the distance from the plane leading edge increases, the heat transfer declines.

Design and optimisation of a multifunctional monolithic filter for fire escape masks

Commercial fire escape masks (FEMs) use packed bed filters to remove gaseous and vaporous toxic components in the event of building fires. Packed bed filters incur a high pressure drop and commercial masks have no method to remove environmental (fire) or process (reaction and adsorption) heats. Here we derive a computationally efficient numeric model based on a bi-linear driving force (LDF) model to investigate the purification of gas streams in a square channelled monolith filter containing an impregnated activated carbon (AC) section to adsorb and react toxic components, and a section consisting of shape stable phase change materials (SS-PCMs) to absorb heat. The modelled test gas mixture contained an adsorbing component, cyclohexane, and a reacting component, carbon monoxide, permitting the combined effects of heat generation, heat absorption, component reaction and component adsorption to be studied for a novel filter. The bi-LDF model was validated against a three-dimensional model and provided excellent accuracy at significantly reduced computational time ca. 99.7%. Additionally, the bi-LDF model was used to optimise the dimensions and configuration of the filter, specifically finding an optimal channel diameter, dch, to wall thickness, tw, aspect ratio of dch=1.3tw. The optimal configuration consisted of an initial 2.0 cm long impregnated AC section followed by a 2.5 cm SS-PCM section at the outlet, providing 18 min of thermal protection whilst preventing cyclohexane vapour breakthrough for 21 min. Pt/TiO2 was confirmed to be a viable CO oxidation catalyst with a minimum weight fraction within the impregnated monolith of 2.5 wt%. The success of this work represents a step change in FEM design and more widely in air purification devices where heat absorption is important.