Influence Of Heat Generation Research Articles

Thermal and mechanical characterisation of friction stir welded dissimilar aluminium alloys

The influence of thermal properties on the friction stir welded (FSW) dissimilar aluminium alloys at different tool rotational speeds and tool pin profiles was studied. AA 5083 H111 and AA 6082 T6 of 6 mm aluminium alloy plates are welded by varying the process parameters. The influence of heat generation and heat transfer in the joint efficiency of the weldments are characterised. Heat flow and heat flux for various tool rotation speeds generated between the tool shoulder and workpiece are calculated and analysed. The rate of heat distribution during welding is evaluated by calculating the thermal diffusivity of AA5083 H111 and AA6082 T6. Microhardness test helps to comprehend the influence of the parameters over the mechanical property of the weldments. The results revealed that the thermal characterisation clearly illustrates that an increase in tool rotation speed directly amplifies the heat flow and heat flux in weldments. However, AA 5083 H111 and AA 6082 T6 for varying temperature and reveals that 580°C possessed higher thermal conductivity for AA 6082 T6 (260 W/m°C) and AA 5083 5083 H111 (160 W/m°C), thermal conductivity for AA 6082 T6 (1260 J/Kg°C) and AA 50835083 H111 (1225 J/Kg°C) and thermal Diffusivity was 5.2029 × 10−5 (m2/s) for AA 5083 H111 and 7.61819 × 10−5 (m2/s) for AA 6082 T6.

Hybrid nanofluid flow and heat transfer in symmetric porous ducts with CuO nanoparticles and multi-walled carbon nanotubes under peristaltic motion

This study focuses on the analysis of peristaltic transport of a hybrid nanofluid comprising deionized water as a base fluid and the multi-walled carbon nanotubes (MWCNTs) and copper oxide (CuO) as nanoparticles within a sinusoidal wavy porous duct, taking into consideration the influence of heat generation or absorption. The inaugural literature piece addresses the utilization of hybrid nanofluid in the context of peristaltic flow within ducts. To simplify the analysis, we have converted the non-dimensional equations into a two-dimensional (2D) coordinate system using the assumptions of a very long wavelength [Formula: see text] and low Reynolds number (Re). The non-dimensional equations governing the behavior of the hybrid nanofluid are then solved numerically using the finite volume method. Numerical solutions for temperature and the 2D peristaltic flow are obtained with the assistance of the Mathematics software MATLAB. These solutions are subsequently represented graphically using MATLAB software. The graphical results highlight several key findings for important parameters. First, it is observed that the pressure rise, temperature profile, and pressure gradient in the hybrid nanofluid (CuMWCNTs/H2O) flow increases as heat generation increases. Furthermore, an increase in the nanoparticle volume fraction of both nanoparticles leads to a decrease in the pressure rise and pressure gradient in the hybrid nanofluid flow. Additionally, the widening of the channel reduces the pressure gradient and pressure rise in the CuMWCNTs/H2O hybrid nanofluid. The analysis also includes the visualization of streamlines for peristaltic transport. These streamlines reveal that an increase in amplitude results in larger bolus sizes, while heightened heat generation has the opposite effect, decreasing bolus sizes. The results of this investigation can be found in various cooling devices as flows in the ducts are very frequently utilized for the cooling process of engines. A further topic is common in applications related to microfluidics, heat exchangers, and biomedical devices where peristaltic pumping is employed. Our results are in 100% agreement with the existing literature in special cases.

Heat transfer analysis of MHD viscous nanofluid flow over a nonlinearly stretching sheet with heat source/sink: A numerical study

The present study analyses the magnetohydrodynamics (MHD) viscous nanofluid flow past a nonlinearly stretching sheet embedded in a porous medium under the influence of heat generation and thermal radiation. Further, variable magnetic field as well as variable permeability is used instead of constant magnetic field and permeability due to many therapeutic applications, which makes them distinctive and practically helpful. The MHD viscous flow and heat transfer equations have been generated as coupled second-order nonlinear partial differential equations using a mathematical model that resembles the physical flow problem. The partial differential equations governing the flow problems are reduced to ordinary differential equations via similarity variables. The reduced equations are then solved by Runge–Kutta–Fehlberg’s scheme with shooting method by the help of MATLAB software. The result obtained reveals that enhancing the heat generation parameter, porosity parameter, and radiation parameter upsurges the temperature of the nanofluid, whereas the magnetic parameter shows the reverse effect in the case of velocity distribution. Nusselt number decreases at the rate of 2.6147% for copper–water nanofluid when increased from 0 to 0.05. Silver nanoparticles have the highest heat transfer as compared to other nanoparticles. Because of this, silver nanoparticles are the most effective thermal conductors for increasing the effectiveness of heat storage in phase transition materials.

Heat transfer analysis of water-ethylene glycol (50:50) based nanofluid over a cone with the influences of magnetic field and uniform heat generation/absorption

Aim:The novelty of the problem is to examine the heat transfer analysis of H2O–C2H6O2 (50:50) mixture based Al2O3 and Fe3O4 over a heated and spinning down-pointing vertical cone with the effect of heat generation or absorption in the presence of magnetic field. Findings:Results are demonstrated in terms of graphs to examine the influence of various physical parameters that come across such as Magnetic parameter M, Spin parameter ϵ, Nanoparticle volume fraction ϕ, Heat generation or absorption parameter Δ, velocity slip parameter Γ1 and thermal slip parameter Γ2 on dimensionless velocity profile F′(y), G(y) and temperature profile H(y). The effect of M, ϵ, ϕ, Δ,Γ1,Γ2on skin friction and local Nusselt number are examined in tabulation form. Significant outcomes:It is pointed out that enhancement in Magnetic parameter and thermal slip parameter leads to declination of the velocity profile. Influence of Heat generation or absorption parameter magnifies the thermal characteristic of the flow. Moreover, the numerical statistics was triggered and catalogued to analogize the results of existing outcomes with those of previous literature for some special cases and established excellent agreement. Fe3O4 possess 0.78% and 0.92% of high surface drag force and heat transfer rate respectively than Al2O3 with respect to heat generation or absorption parameter. Approach:The system of partial differential equations is transformed into set of nonlinear ordinary differential equations. Solutions for the system of nonlinear Ordinary differential equation are obtained by Numerical method. The numerical scheme is developed based on fourth order Runge Kutta scheme along with shooting techniques. Practical implications:In this current growing scenario, engineers and scientists are making an endeavour to gratify the global needs. Nanofluids are considered as inevitable one for achieving industrial and global needs. The investigation of heat transfer over rotating cone with the effect of magnetic field is of considerable interest due to its presence in industrial and technological applications. Especially in the design of turbines and turbo equipment’s and in understanding the path of flight of rotating wheels.

Magneto radiative and heat convective flow boundary layer in Maxwell fluid across a porous inclined vertical plate

Heat transport in a 2D steady radiative boundary layer with Maxwell fluid flow and the influence of heat generation and MHD has been studied across a porous inclined vertical plate. Through similarity transformation, the mathematical modelling is converted to ODEs, and the built-in solver Bvp4c via MATLAB is used to solve. The linear movement of an inclined porous plate introduced the flow. The MHD (M), Prandtl number (Pr), radiation (Rd), Rayleigh number (Ra), local Nusselt number (Nux), angle of inclination (γ), and material relaxation time (β) have a considerable impact on the flow field as a result. The local Nusselt numbers and the skin friction coefficient are also given as numbers. The validation with the numerical solution is presented. The results are shown, and a thorough physical analysis has been done. The temperature of the fluid rises due to the greater electric field, increasing the heat transfer on the inclined plate. However, skin friction increases dramatically as the heat radiation parameter rises. The critical findings of this study are that the temperature profile increases and the velocity profile lower as the inclination angle increases. The Maxwell fluid parameter raises the velocity profile as well.

Liquid Coating with Variable Thermal Conductivity on a Pipe under Influence of Thermal Radiation and Heat Generation

Flow over a pipe or an elongated cylinder is widely applied in many engineering processes like wire coating and pipe coating. This encourages the present study to examine the fluid flow and heat transfer over a horizontal stretching cylinder with the impact of temperature-reliant thermal conductivity and thermal radiation. The influence of heat generation is also considered. The Carreau rheology model is applied to represent the liquid coating. The similarity technique is used to simplify the developed governing equations and then solved by the homotopy analysis method. The effects of the pertinent parameters such as the thermal conductivity parameter and Weissenberg number on the fluid field and heat transfer are studied by applying the calculated series of analytical solutions, which are scrutinized through graphs and tables. The Nusselt number has a negative function with the radiation and thermal conductivity parameters. Furthermore, the Weissenberg number affects the velocity and temperature profiles differently in conditions n < 1 and n ≥ 1, respectively. The present results are essential in optimizing the pipe coating process.

NUMERICAL ANALYSIS OF NEWLY DEVELOPED FRACTAL-FRACTIONAL MODEL OF CASSON FLUID WITH EXPONENTIAL MEMORY

In the current research community, certain new fractional derivative ideas have been successfully applied to examine several sorts of mathematical models. The fractal fractional derivative is a novel concept that has been proposed in recent years. In the presence of heat generation, however, it is not employed for the free convection Couttee flow of the Casson fluid model. The core interest of the present analysis is to examine the Casson fluid under the influence of heat generation and magnetic field. The flow of the Casson fluid has been considered in between two vertical parallel plates. The distance between the plates is taken as [Formula: see text]. The linear coupled governing equation has been developed in terms of classical PDEs and then generalized by employing the operator of the fractal-fractional derivative with an exponential kernel. The numerical solution of the proposed problem has been found employing the finite-difference technique presented by Crank–Nicolson. The Crank–Nicolson finite difference scheme has the advantage of being unconditionally stable and can be applied directly to the PDEs without any transformation to ODEs. This technique in sense of exponential memory has been revealed to be unreported in the literature for such a proposed problem. For graphical analysis, the graphs of velocity profile and thermal field have been plotted in response to several rooted parameters. For comparative analysis, the graphs for the parameter of fractal-fractional, fractional, and classical order have also been plotted. From the analysis, it has been found that the fractal-fractional order model has a large memory effect than the fractional-order and classical model due to the fractal order parameter.

Recent Patents on Cooling System of CNC Machine Tools

Abstract: With the development of machine tools for high precision and high automation, the problem of thermal deformation has become very prominent. As the spindle speed, feed rate, and effective working time of CNC machine tools are much higher than those of ordinary machine tools, the influence of heat generation and thermal deformation of machine tools on machining accuracy is far greater than that of ordinary machine tools. High-efficiency, high-precision processing machine tools, and CNC machine tools require high accuracy and stability. Therefore, the design and manufacturing of CNC machine tools must fully consider the impact of thermal deformation on machining accuracy and take corresponding measures. The cooling of the CNC machine tools can improve the machining efficiency of the machine tools, the quality of parts processing, and the service life of the CNC machine tools. Various representative patents and papers on the cooling of CNC machine tools at home and abroad have been reviewed. By summarizing a large number of patents and papers on the cooling of CNC machine tools, the cooling methods and methods of CNC machine tools, the recovery, and treatment of coolant are analyzed, and the development trend of CNC machine tools is discussed. The improvement of the CNC machine tools cooling system has a great impact on improving machining accuracy, efficiency, and stability. Therefore, more patents on CNC machine tool cooling systems will emerge in the future.

MHD Williamson Nanofluid Fluid Flow and Heat Transfer Past a Non-Linear Stretching Sheet Implanted in a Porous Medium: Effects of Heat Generation and Viscous Dissipation

The present study is carried out to examine the behavior of magnetohydrodynamic Williamson nanofluid flow and heat transfer over a non-linear stretching sheet embedded in a porous medium. In the current work, the influence of heat generation and viscous dissipation has been taken into account. The considered phenomenon in the form of partial differential equations is transformed into ordinary differential equations by utilizing an appropriate similarity transformation. The reduced form is solved by using rigorous MATLAB built-in solver bvp4c. The numerical solutions for the velocity field, temperature field, and mass concentration along with the skin friction coefficient, Nusselt number, and Sherwood number are computed. The obtained solutions are shown in graphs and are discussed with physical reasoning. It is noted that by increasing Williamson fluid parameter W, the velocity decreases and concentration profile increases. It is deduced that increasing Eckert number Ec leads to a rise in temperature and mass concentration. It has been viewed that with the increment in heat generation parameter Q, the temperature field increases and concentration decreases. The results show that an increasing magnetic field parameter M leaves a decreasing trend in the velocity field and an increasing trend in the temperature field and concentration profile. The present results are compared with the existing solution which shows good agreement and endorses the validation of current solutions.

Influence of wall friction on flow parameters in natural gas transmission pipeline

A mathematical model and computational algorithm are derived for the prediction of natural gas pipeline flow. Non-isothermal and compressible steady-state flow is considered. Heat transfer between gas flow and surroundings is taken into account together with the heat generation due to the gas friction on the inner pipeline wall. The computational algorithm is based on the marching procedure with defined initial conditions. The predicted thermal effect of the wall friction is validated by the simulation of a case that is available in the open literature. The influence of heat generation by gas wall friction in the long transmission pipeline on gas pressure and temperature is evaluated. Differences between results obtained with and without the heat generation due to gas wall friction are analysed. The heat generation due to gas friction on the pipeline inner wall has an influence on the gas temperature change along the pipeline, while its influence on the pressure drop is negligible. These detailed results are novel since most of the previously published results on non-isothermal gas flow did not take into account the thermal effect of the gas wall friction or the influence of this effect was not evaluated. The presented results are a support to the gas pipeline design methods and operational analyses.

Static ultrasonic welding of carbon fibre unidirectional thermoplastic materials and the influence of heat generation and heat transfer

Ultrasonic welding is a promising technology to join fibre-reinforced thermoplastic composites. While current studies are mostly limited to fabric materials the applicability to unidirectional materials, as found in aerospace structures, would offer opportunities for joining primary aircraft structures. However, due to the highly anisotropic flow of a molten unidirectional ply undesired squeeze flow phenomena can occur at the edges of the weld overlap. This paper investigates how the fibre orientation in the plies adjacent to the weld line influences the welding process and the appearance of edge defects. Ultrasonic welding experiments with different layups and energy director configurations were carried out while monitoring temperatures at different locations inside and outside the weld overlap. The joints were characterized by single lap shear tests, analysis of corresponding fracture surfaces and microscopic cross-sections. Results showed that the anisotropic flow and the anisotropic thermal conductivity of the plies adjacent to the weld line have a distinct effect on the appearance and location of edge defects. By using energy directors that cover only part of the weld overlap area a new approach was developed to mitigate edge defects caused by the highly directional properties of the unidirectional plies.

Exploration of cubic autocatalysis and thermal relaxation in a non-Newtonian flow field with MHD effects

This paper relates to the study of cubic autocatalysis in non-Newtonian Casson fluid with magnetohydrodynamic (MHD) effects. The homogeneous reaction is supposed to be provided by isothermal cubic autocatalytic kinetics and the heterogeneous reaction by first order kinetics. The boundary layer flow is discussed in case when both reactant and auto-catalyst have equal diffusion coefficients. The thermal relaxation and heat transfer on the flow of Casson fluid is examined through Cattaneo–Christov heat diffusion under the influence of heat generation. The fluid flow is taken over the stretching cylinder. The independent variables in a coupled partial differential system are reduced through similarity transformation. The numerical results for the reduced coupled system are found by means of Runge–Kutta Fehlberg method along with shooting scheme. The fluid temperature trend declines when uplifting thermal relaxation parameter. The fluid concentration trend decreases when increasing the strength of homogeneous and heterogeneous reaction parameter. Also, the heat transfer rate for thermal relaxation parameter is examined numerically.

Photothermal Effect in Plasmonic Nanotip for LSPR Sensing.

The influence of heat generation on the conventional process of LSPR based sensing has not been explored thus far. Therefore, a need exists to draw attention toward the heat generation issue during LSPR sensing as it may affect the refractive index of the analyte, leading to incorrect sensory conclusions. This manuscript addresses the connection between the photo-thermal effect and LSPR. We numerically analyzed the heat performance of a gold cladded nanotip. The numerical results predict a change in the micro-scale temperature in the microenvironment near the nanotip. These numerical results predict a temperature increase of more than 20 K near the apex of the nanotip, which depends on numerous factors including the input optical power and the diameter of the fiber. We analytically show that this change in the temperature influences a change in the refractive index of the microenvironment in the vicinity of the nanotip. In accordance with our numerical and analytical findings, we experimentally show an LSPR shift induced by a change in the input power of the source. We believe that our work will bring the importance of temperature dependence in nanotip based LSPR sensing to the fore.

Influence of heat generation on magnetohydrodynamic (MHD) flow using a theory of kinetics for liquids

In the present article, the influence of heat generation on the magnetohydrodynamic (MHD) flow of an Eyring–Powell fluid along a permeable plate has been explored. The influence of heat generation or absorption on a steady flow of non-Newtonian fluid over a surface is investigated. The governing equations obtained from Eyring–Powell fluid model are transubstantiated into ordinary differential equations using suitable transformations. Along with the Runge–Kutta method, we attained a numerical solution of the present problem by explicating the shooting technique. Influences of distinct parameters on temperature and the velocity field profiles are highlighted in graphs and tables. The acceleration in the value of γ, velocity profile shows decreasing behavior, but recovery occurs with an increase in M. The streamlines and three-dimensional results have been shown graphically for a selection of different parameters. Numerical results of the present work have been discussed with the support of tables.

Influence of Heat Generation and Viscous Dissipation on Hydromagnetic Fully Developed Natural Convection Flow in a Vertical Micro-Channel

Influence of Heat Generation and Viscous Dissipation on Hydromagnetic Fully Developed Natural Convection Flow in a Vertical Micro-Channel

MHD Flow of Brinkman Type H₂O-Cu, Ag, TiO₂ and Al₂O₃ Nanofluids with Chemical Reaction and Heat Generation Effects in a Porous Medium

This paper studies magnetohydrodynamic (MHD) flow of Brinkman type nanofluids with the influence of heat generation, chemical reaction and thermal radiation. The f luid i s taken ov er a v ertical plate flat p assing through a porous medium. Four distinct types of nano particles (Cu, Ag, TiO₂ and Al₂O₃) are taken in a base fluid H₂O. The vertical plate with constant temperature is oscillating in its own plane. The flow is described by the partial deferential equations with suitable initial and boundary conditions. The Laplace transform method is used to obtain the exact solutions for velocity, temperature and concentration. These solutions are interpreted graphically using computational software Mathcad-15 to analyze the influence of embedded parameters such as Brinkman parameter, permeability of porous medium, chemical reaction parameter, nano particle volume fraction, heat generation parameter, magnetic parameter and radiation parameter. Skin-friction, Sherwood number and Nusselt number are calculated mathematically.

Heat transfer from moving exponential fins exposed to heat generation

The heat transfer through exponential fins in movement and under the influence of heat generation (absorption) is the fundamental subject of the present paper. Obtaining exact formulas for the thermal features like the distribution of temperature as well as the efficiency of exponential fins is the main target. As a consequence of the current research, combined effects of the Peclet number due to the fin movement, and of the heat generation parameter due to the presence of a heat source on the efficiency of exponential fins versus rectangular fins can be analyzed and compared. Better fin efficiency anticipated for growing type of exponential fins provides practical advantages for the designing engineers. Moreover, simulation of more complex phenomena using modern numerical schemes can be tested by the presented closed-form formulae.

Influence of heat generation and heat flux on peristaltic flow with interacting nanoparticles

In the current study, we have examined the peristaltic flow of three different nanoparticles with water as base fluid under the influence of slip boundary conditions through a vertical asymmetric porous channel in the presence of MHD. The selected nanoparticles are titanium dioxide ( TiO2 , copper oxide (CuO) and silicon dioxide ( SiO2 . The Brownian motion shows that the effective conductivity increases to result in a lower temperature gradient for a given heat flux. To examine these transport phenomena thoroughly, we also consider the thermal conductivity model of Brownian motion for nanofluids, this increases the effect of the particle size, particle volume fraction and temperature dependence. The mathematical formulation is presented. Exact solutions are obtained from the resulting equations. The obtained expressions for pressure gradient, temperature and velocity profile are described through graphs for the various relevant parameters. The streamlines are drawn for some physical quantities to discuss the trapping phenomenon.

Numerical modelling of self-heating effects on guiding modes of high-power photonic crystal fibre lasers

The influence of heat generation on propagating modes in a high-power large-mode-area photonic crystal fibre laser was investigated. The temperature distribution, temperature gradient, thermally induced stresses were first simulated. Then the Maxwell’s wave equation with taking the thermal refractive index tensor into account was solved to observe the effects of heat on propagating modes. The results show sensible modifications for TE, TM, and EH mode profiles. However, the linear polarized fundamental mode (HE) was not affected under thermal effects.

Numerical modelling of self-heating effects on guiding modes of high-power photonic crystal fibre lasers

The influence of heat generation on propagating modes in a high-power large-mode-area photonic crystal fibre laser was investigated. The temperature distribution, temperature gradient, thermally induced stresses were first simulated. Then the Maxwell’s wave equation with taking the thermal refractive index tensor into account was solved to observe the effects of heat on propagating modes. The results show sensible modifications for TE, TM, and EH mode profiles. However, the linear polarized fundamental mode (HE) was not affected under thermal effects.