Joule Heating Effect Research Articles

Numerical study of Williamson fluid flow and heat transfer over a permeable stretching cylinder with the effects of Joule heating and heat generation/absorption

AbstractThe present study aims to discuss the Williamson fluid flow and heat transfer across a permeable stretching cylinder with heat generation/absorption effects. The effects of viscous dissipation, Joule heating, and magnetic field are also taken into account. The BVP‐4C numerical solver in MATLAB is adopted for all the numerical simulations in the present study. For this, the modeled partial differential equations are translated into dimensionless ordinary differential equations using some well‐developed similarity transformations. A good agreement between the numerical results of the present study and existing literature is exhibited. The dimensionless physical parameters being investigated are Reynolds number, magnetic field parameter, suction parameter, heat source/sink parameter, Williamson fluid parameter, and mixed convection parameter. The numerical calculations are also performed for the skin friction coefficient and local Nusselt number to get an understanding of the shear stress rate and heat transfer rate, respectively. Furthermore, the impact of all these physical parameters on the velocity and temperature profiles is investigated and represented throughout the literature.

Rational Design of Ti3C2Tx MXene Inks for Conductive, Transparent Films.

Transparent conductive electrodes (TCEs) with a high figure of merit (FOMe, defined as the ratio of transmittance to sheet resistance) are crucial for transparent electronic devices, such as touch screens, micro-supercapacitors, and transparent antennas. Two-dimensional (2D) titanium carbide (Ti3C2Tx), known as MXene, possesses metallic conductivity and a hydrophilic surface, suggesting dispersion stability of MXenes in aqueous media allowing the fabrication of MXene-based TCEs by solution processing. However, achieving high FOMe MXene TCEs has been hindered mainly due to the low intrinsic conductivity caused by percolation problems. Here, we have managed to resolve these problems by (1) using large-sized Ti3C2Tx flakes (∼12.2 μm) to reduce interflake resistance and (2) constructing compact microstructures by blade coating. Consequently, excellent optoelectronic properties have been achieved in the blade-coated Ti3C2Tx films, i.e., a DC conductivity of 19 325 S cm-1 at transmittances of 83.4% (≈6.7 nm) was obtained. We also demonstrate the applications of Ti3C2Tx TCEs in transparent Joule heaters and the field of supercapacitors, showing an outstanding Joule heating effect and high rate response, respectively, suggesting enormous potential applications in flexible, transparent electronic devices.

Thermal transport in nanofluid across a radiated permeable sheet with irreversible effects based on the shape of the particles

Purpose The purpose of this study is to examine the flow and heat transfer performance of titanium oxide/water and copper/water nanofluids with varying nanoparticle morphologies by considering magnetic, Joule heating and viscous dissipation effects. Furthermore, it studies the irreversibility caused by the flow of a hydromagnetic nanofluid past a radiated stretching sheet by considering different shapes of TiO2 and Cu nanoparticles with water as the base fluid. Design/methodology/approach In this study, the authors investigated entropy production in an unsteady two-dimensional magneto-hydrodynamic nanofluid regime using water as the base fluid and five unique TiO2 and Cu nanoparticle morphologies. Using appropriate similarity transformations, the controlling nonlinear system of partial differential equations is transformed into a system of ordinary differential equations. The shooting technique with Runge–Kutta method was then used to solve these equations quantitatively. The findings of this study are depicted graphically, and the skin friction corresponding to various nanoparticle geometries and physical parameter variations is tabulated. Findings To assess the reliability of the current findings, a tabular representation of the data was compared to that of previously published studies. It is noted that a reduction in thermal energy was detected as a result of the higher levels of Prandtl number (Pr). It is further analysed that the highest heat energy generation of TiO2 nanoparticles was larger than that of Cu nanoparticles. The most important finding was that the sphere-shaped Cu/H2O nanofluid had the lowest velocity and greatest temperature. Also, Cu nanoparticles in the shape of platelets generate the most entropy, while TiO2 nanoparticles in the shape of spheres generate the least. Originality/value To the best of the knowledge of the authors, the attempt to investigate the previously unexplored shape effects of TiO2 and Cu nanoparticles on the heat transfer enhancement and inherent irreversibility caused by hydromagnetic nanofluid flow past a radiated stretching sheet with magnetic, Joule heating and viscous dissipation effects. This study fills this gap in the existing literature and encourages scientists, engineers and businesses to do more research in this area. This model can be used to improve heat transfer in systems that use renewable energy, thermal management in industry and the processing of materials.

Convective heat transfer and MHD flow through semi-porous cylindrical filters embedded in an impermeable region

• Magnetic field dominate the flow field and suppresses the flow rate. • Maximize the effect of Hartmann number leads to rise in temperature distribution for the flow. • Heat transfer in the flow is enhanced as the Darcy number increased. • A negative pressure gradient influences the flow immensely. In the present study, profound applications of agriculture, industries and engineering have motivated to report an exact solution for steady incompressible axisymmetric electrically conducting fluid flow through a semi-porous media surrounded by an impervious cylinder. The uniqueness of this paper is to propose the effect of Joule heating by incorporating convection terms which allows to improve the flow model. Further, the non-dimensional parameters applied on equations governing the flow, takes the form of non-linear differential equations. A Differential Transform Method (DTM) is employed directly to the non-linear differential equations. A succinct solution for velocity and temperature is obtained and its variation on the fluid flow is observed for different dimensionless parameters. This is an interesting phenomenon graphically revealed by Skin-friction and Nusselt number. A good agreement is found in the current paper with certain added features by making the equations compatible and well matched with the previous work of research investigators.

Influence of oxygen on the optical, electrical, and heating properties of gallium-doped zinc oxide (GZO) films

Thin-film transparent heaters (TFTHs) are gaining popularity in optoelectronics and a variety of domestic applications, including smart windows, car defrosters, and other devices. The deposition and characterization of TFTHs made of gallium-doped zinc oxide (GZO) are presented in this work. GZO thin films were deposited via pulsed laser deposition on glass substrates with varying oxygen partial pressures from 0 to 10 mTorr during deposition. The samples demonstrated very low sheet resistance values between 5 and 17 Ω/sq from 0 to 10 mTorr, respectively. UV/vis transmission spectra revealed that TFTHs have a high optical transparency above 80%. GZO-based TFTHs demonstrated a consistent and repeatable joule heating effect, with temperatures reaching 76 °C with a low input voltage of 10 V. This research could guide the future use of GZO as a transparent conducting oxide material for many potential cost-effective applications from low-powered electronics to lightweight and wearable devices.

Effect of Elastoplastic Thermal Softening on Electrical Contact Resistance Based on the Dual-Iterative Coupling Method

Electrical contact resistance (ECR) affecting the work behavior is a key index to evaluate the electrical contact capacity of electrical connectors. A large number of factors affecting ECR exist, among which elastoplastic thermal softening (EPTS) caused by temperature rise has a significant effect on ECR. Thus, a high-accuracy dual-iterative coupling method (DICM) is proposed to explore the influence of EPTS on ECR. First, according to the characterization results of the real rough surface, a finite element model (FEM) including a rough surface is created, and the contact state is improved by the contact adjustment method to achieve accurate coupling analysis. Second, the grid dimension is optimized to select an optimal mesh size for the contact surface in terms of computational efficiency and accuracy. Then, a refined numerical model is established. Meanwhile, the validity of the FEM is checked by the experimentally measured ECR. Finally, the impact of EPTS on ECR is revealed through the DICM. The results show that the electrical contact interface suffers from apparent temperature rise due to the Joule heating effect, which causes the ECR to decrease in a different degree under two loading conditions when EPTS is taken into account. Therefore, if a numerical simulation is used to predict the ECR, a DICM should be adopted to obtain more accurate prediction results.

Ultrathin Wood‐Derived Conductive Carbon Composite Film for Electromagnetic Shielding and Electric Heating Management

AbstractRecently, wood‐based composites have absorbed widespread concern in the field of electromagnetic interference (EMI) shielding due to their sustainability and inherent layered porous structure. The channel structure of wood is often used to load highly conductive materials to improve the EMI shielding performance of wood‐based composites. However, there is little research on how to use pure wood to prepare ultrathin EMI shielding materials. Herein, ultrathin veneer is obtained by cutting wood in parallel to the annual rings. Then, carbonized wood film (CWF) is prepared by a simple two‐step compressing and carbonization. The specific EMI shielding effectiveness (SSE/t) of CWF‐1200 with an ultrathin thickness (140 µm) and high electrical conductivity (58 S cm−1) can reach 9861.41 dB cm2 g−1, which is much higher than other reported wood‐based materials. In addition, the zeolitie imidazolate framework‐8 (ZIF‐8) nanocrystals are grown in situ on the surface of the CWF to obtain CWF/ZIF‐8. CWF/ZIF‐8 exhibits an EMI shielding effectiveness (SE) of up to 46 dB and an ultrahigh SSE/t value of 11 330.04 dB cm2 g−1 in X band. In addition, the ultrathin CWF also shows an excellent Joule heating effect. Therefore, the development of ultrathin wood‐based film provides a research basis for wood biomass to replace traditional non‐renewable and expensive electromagnetic (EM) shielding materials.

Effects of viscous dissipation and joule heating of magnetohydrodynamics (MHD) convective nano fluid heat transfer over a flat porous plate

In the present investigation, we studied the effects of Viscous Dissipation and Joule Heating of magnetohydrodynamic (MHD) convective heat transfer over a flat porous plate. The governing partial differential equations is expressed into a nonlinear partial differential equation, using a suitable similarity transformation. A semi analytical method of Homotopy Parturbation was applied to solve the equation and the obtained numerical solution for the velocity, temperature and other parameters of the nano fluid are discussed and represented graphically. Also, the effect of other parameters on the velocity and temperature profiles are also presented.

Effects of Joule Heating, Viscous Dissipation, and Activation Energy on Nanofluid Flow Induced by MHD on a Vertical Surface

This study investigates magnetohydrodynamic (MHD) nanofluid flow through a stretching vertical surface influenced by Joule heating, chemical reaction, viscosity dissipation, thermal radiation, and activation energy. Such physical problems have significance in applied mathematics, engineering, and physics, and they are frequently found in symmetrical scenarios. A transformation of the similarity technique is used to reduce the difficulty of the boundary layer equations for nonlinear motion, energy, solute, and nanoparticle concentration. To identify these variations with local similarity, we employ symmetry analysis. The altered equations were solved using the shooting technique with Matlab bvp4c. It was found that raising the Schmidt number increases the impact of temperature and concentration profiles. As the Biot number and thermal radiation rise, the local Nusselt number, local Sherwood number, and skin friction increase as well. The comparative table shows good agreement with the current results.

Numerical simulation of MHD two‐dimensional flow incorporated with joule heating and nonlinear thermal radiation

AbstractThe current investigation presents a numerical simulation of boundary layer flow with heat transfer. The study primarily emphasizes heat generation due to the influence of nonlinear thermal radiation. Moreover, the simultaneous effects of Joule heating and viscous dissipation have been incorporated for the thermal enhancement of the magnetohydrodynamics (MHD) on the convective boundary layer flow over a flat plate. Dimensional analysis is brought into use to determine the hydro and thermal boundary layer thickness for the two‐dimensional flow. Subsequently, the application of the suitable similarity transformation yields a nonlinear coupled flow problem with is solved numerically with the help of the Runge–Kutta Fehlberg (RKF) method incorporated with the Shooting technique. Moreover, this theoretical study highlights the immense mechanical and aeronautical applications of thermal radiation. In view of computational findings and simulating results, linear and nonlinear thermal radiation effects can also be investigated on fluids passing through a cylinder and channels. Finally, computational data tabulated against some pertinent parameters and parametric study reveal that non‐linear thermal radiation is more effective for highly viscous fluids.

Tunable Photoresponse in a Two-Dimensional Superconducting Heterostructure.

The photo-induced superconducting phase transition is widely used in probing the physical properties of correlated electronic systems and to realize broadband photodetection with extremely high responsivity. However, such photoresponse is usually insensitive to electrostatic doping due to the high carrier density of the superconductor, restricting its applications in tunable optoelectronic devices. In this work, we demonstrate the gate voltage modulation to the photoresponsivity in a two-dimensional NbSe2-graphene heterojunction. The superconducting critical current of the NbSe2 relies on the gate-dependent hot carrier generation in graphene via the Joule heating effect, leading to the observed shift of both the magnitude and peak position of the photoresponsivity spectra as the gate voltage changes. This heating effect is further confirmed by the temperature and laser-power-dependent characterization of the photoresponse. In addition, we investigate the spatially-resolved photocurrent, finding that the superconductivity is inhomogeneous across the junction area. Our results provide a new platform for designing tunable superconducting photodetector and indicate that the photoresponse could be a powerful tool in studying the local electronic properties and phase transitions in low-dimensional superconducting systems.

Transient MHD flow of fractional Burger's fluid model through a parallel microchannel with heat transfer and slip boundary condition

The combined influence of magnetic field, electro-osmotic flow (EOF), and pressure gradient on the unsteady magnetohydrodynamic fluid flow through a parallel microchannel is investigated. The Burger's liquid model is used for the fractional partial differential equation, which allows us to study the behavior of viscoelastic liquid velocity profile in the parallel microchannel. The Laplace transform (LT) in concert with the Fourier cosine transform are used to obtain the analytical solution of the velocity profile. Furthermore, using the method of separation of variables, the energy equation, Joule heating, energy dissipation, and electromagnetic effects are calculated to obtain the temperature within the microchannel. The influence of some relevant parameters like heat transfer, temperature distribution, Hartmann number (Ha), and Brinkman number (Br) on fluid flow velocity are presented graphically and discussed. The results obtained show that temperature decreases with Ha and Br of the transverse electric field for slip flow. Close to the middle of the microchannel, fluid flow velocity increases with decrease in the delay time parameter value and increase in the Burger's parameter value, while the opposite trend is found for the velocity near to the middle of the microchannel. In addition, Burger's liquid is quite general, such that Oldroyd-B, Maxwell, and Newtonian liquids are readily obtained as limiting cases. The study is significant in the application fields of chemical analysis and biological analysis, drug delivery, bacteria detection, and some others.

Investigation of Different Oxygen Partial Pressures on MgGa2O4-Resistive Random-Access Memory.

Different oxygen partial-pressure MgGa2O4-resistive RAMs (RRAMs) are fabricated to investigate the resistive switching behaviors. The X-ray photoelectron spectroscopy results, set voltage, reset voltage, cycling endurance, and retention time are drawn for comparison. With the increasing oxygen ratio gas flow, the resistive switching characteristics of MgGa2O4 RRAM are drastically elevated by changing the fabrication conditions of the RS layer. Moreover, we portray a filament model to explain the most likely mechanism associated with the generation and rupture of conductive filaments composed of oxygen vacancies. The formation of the interfacial layer (AlO x ) and the participation of the Joule heating effect are included to explain the highly distributed high-resistance state (HRS). The high randomness among switching cycles for memory application should be prevented, but it is suitable for the physical unclonable function. The relationship between HRS and the next time set voltage shows a strong correlation, and the conduction mechanisms of the low-resistance state (LRS) and HRS correspond to ohmic conduction and space charge-limited conduction, respectively. Meanwhile, the RRAM undergoes 10,000 s retention tests, and the two resistance states can be distinguished without obvious alternation or degradation. A favorable cycling endurance and retention time achieved by optimizing the fabrication parameters of Al/MgGa2O4/Pt RRAM have the potential for nonvolatile memristors and information security applications.

Self-sensing and self-healing smart fiber-reinforced thermoplastic composite embedded with CNT film

Impacts can degrade the strength of composite structures; thus, impact damages should be monitored and repaired. In this study, a novel composite consisting of carbon nanotube film and glass fiber-reinforced thermoplastic was thermoformed. The fabricated smart composite demonstrated self-sensing and self-healing capabilities for damage caused by low-energy impacts. Elastic deformation of the composite caused by a 0.5-J impact was monitored from the immediate change in resistance of approximately 0.25 Ω. Internal damage such as tears and debonding was detected in real time by monitoring the permanent resistance variation of approximately 0.4 Ω using a Wheatstone bridge with a 3-J impact on the smart composite. This difference occurs because a 3-J impact discontinues the conductive path of the carbon nanotubes and changes the total resistance of the smart composite. The internal damage caused by a 3-J impact was repaired through the Joule heat effect when 0.7 MPa and 55 V were applied to heat the composite to 330°C. A three-point bending test demonstrated that the self-healing efficiency of the smart composite reached 87% in terms of flexural strength.

Entropy approach of hydromagnetic Williamson nanofluid flow with Joule heating

The current investigation, the flow of a hydromagnetic Nanofluid Williamson over an unsteady via a porous medium while stretching a sheet is being analysed along with the impact of thermal radiation and magnetic field on its flow properties. Slip condition between the nanofluid and stretching sheet is also considered. Appropriate similarity transformations are used for converting into a dimensionless form the governing equations with boundary conditions. The derived conventional differential equation was solved using the method of spectral local linearisation. After completing the numerical simulation, the outcomes are presented through different graphs and tables. The momentum conservation equation used in research papers on Williamson nanofluids, hitherto, was corrected. The effect of Joule heating has been considered in the temperature and entropy generation equations for Nanofluid flow over a stretched sheet by Williamson. The growth in the Weissenburg parameter (We) decreases the velocity profile. However, it increases the concentration and temperature distributions. Higher values of the temperature difference parameter ( α ) are seen to decrease the entropy generated in the nanofluid system. The Reynolds number (Re) and the Brinkman number show the opposite tendency. The results have been validated with existing research and our results are found to be in great agreement.

Sensitivity analysis of nonlinear convective heat transport of a hybrid nanoliquid sandwiched by micropolar liquid using RSM

Petroleum and polymer industries utilize a multilayer flow model for efficient heat transfer. In such applications, the linear Boussinesq approximation is not recommended as the devices used in such experiments would work at moderate or extremely high temperatures. Therefore, the flow and heat transfer in a multilayer vertical channel with a magnetic field and the nonlinear (quadratic) Boussinesq approximation are investigated, with the central region filled with a hybrid nanoliquid and the outer regions filled with an oil-based micropolar liquid. The effects of Joule heating and viscous dissipation are taken into account. The effective viscosity and thermal conductivity are modeled using the experimental data based Esfe model. The modeled equations are coupled and nonlinear, they are solved using the Differential Transform Method (DTM). Results are analyzed for various values of the material parameter, quadratic convection parameter, Brinkman number, mixed convection parameter, Hartmann number, nanoparticle volume fraction (NVF) on Nusselt number, skin friction, velocity, microrotation velocity and temperature distributions. Additionally, multi-objective optimization of Nusselt number and friction factor is performed for three different levels of the quadratic convection parameter , material parameter and the NVF using the Response Surface Methodology (RSM). The material parameter diminishes the velocity whereas enhances the microrotation velocity. Also, the quadratic convection parameter increases the flow field. Sensitivity computations reveal that the Nusselt number is more sensitive to material parameter and NVF whereas the skin friction coefficient is more sensitive to quadratic convection parameter.

Numerical Crank-Nicolson methodology analysis for hybridity aluminium alloy nanofluid flowing based-water via stretchable horizontal plate with thermal resistive effect

Hybrid nanofluid (HNF) is a new and improved type of nanofluid models that is widely employed in fluid flow regimes to increase thermal efficiency. The purpose of this effort is to investigate HNF flow in two dimensions over a horizontal sheet while accounting for the effects of Joule heating, viscous dissipation, suction, and thermal slip. The impact of regulating parameters on skin friction and heat transfer is also investigated. HNF used in this investigation is a mixture of water and two types of solid nanoparticles, namely aluminium alloys AA7072 and AA7075. The numerical solutions of partial differential equations are obtained using the Crank-Nicolson method. The outcomes are illustrated in detailed ranges of the connection parameters. The thermal slip effect diminishes the temperature outline from the system and wall temperature. Shrinking sheet movement plays a key role in manipulating fluidity and thermal dispersal. Magnetic strength pulls down the fluidity and wall temperature meanwhile, it assists the thermal dispersion, fractional force, and Nusselt number.

Multiple solutions and their stability for a Ti-alloy nanofluid saturated Darcy porous medium: Flow separation and reversal

In this article, the authors provided the stability analysis for Darcy porous medium saturated by a Ti-alloy nanofluid in the presence of tilted magnetic field, Joule heating, heat generation, and velocity slip effects. The Tiwari-Das model is implemented and the relevant similarity transformations are identified for mathematical modeling of the proposed fluid flow problem. The set of resultant ODEs has been solved using the shooting method in conjunction with the RK-4th order scheme. The existence of dual solutions is observed along with their critical values for the present setup at and after the bifurcation point but for a limited range of certain fixed parameters. Through the eigenvalue approach, it is shown that the first solutions are stable, but not the second solutions. The streamlines are depicted to understand the flow patterns in addition to the identification of flow separation point and flow reversal. The important findings are as follows: (a) the delay of boundary layer separation is pointed out with the enhancing values of volume fraction of Ti-alloy nanoparticles and the inclined magnetic parameter in the presence of suction, (b) the Ti-alloy nanofluids velocity rises but the temperature decays with rising values of the Ti-alloy nanoparticle volume fraction, and (c) the value of smallest eigenvalues is growing with the growing values of magnetic parameter. Finally, this type of research may be extremely beneficial in the fields of aerodynamics (i.e. production of engine components, aircraft turbines, and high-performance automatic parts) and medicine.

Analysis of Heat Transport in a Powell-Eyring Fluid with Radiation and Joule Heating Effects via a Similarity Transformation

Heat transfer in an Eyring-Powell fluid that conducts electricity and flows past an exponentially growing sheet is considered. As the sheet is stretched in the x direction, the flow develops in the region with y > 0. The problem is tackled through a set of partial differential equations accounting for Magnetohydrodynamics (MHD), radiation and Joule heating effects, which are converted into a set of equivalent ordinary differential equations through a similarity transformation. The converted problem is solved in MATLAB in the framework a fourth order accurate integration scheme. It is found that the thermal relaxation period is inversely proportional to the thickness of the thermal boundary layer, whereas the Eckert-number displays the opposite trend. As this characteristic number grows, the temperature within the channel increases.

Effects of Chemical Reaction and Joule Heating on MHD Generalized Couette Flow between Two Parallel Vertical Porous Plates with Induced Magnetic Field and Newtonian Heating/Cooling

In this article, the effects of chemical reaction and Joule heating on MHD generalized Couette flow between two vertical porous plates with induced magnetic field and Newtonian heating/cooling have been investigated. The mathematical model used for the MHD generalized Couette flow takes into account the effect of viscous dissipation. The system of nonlinear partial differential equations governing the flow was solved numerically using the finite difference method. The resulting numerical schemes are simulated in MATLAB to obtain the profiles of the flow variables such as velocity, induced magnetic field, temperature, and concentration profiles graphically. Also, the effects of the flow parameters on the skin‐friction coefficient, Nusselt number, and Sherwood number are obtained and discussed numerically through tabular forms. The findings show that an increase in the chemical reaction parameter leads to a decrease in the concentration profiles. Also, increase in the Joule heating parameter and heat generation parameter leads to an increase in the temperature profiles. Induced magnetic field profiles increase with an increase in Reynold’s number. The findings of this study are important due to its application in developing a variety of chemical technologies, including polymer manufacturing, MHD pumps, food processing, chemical catalytic reactors, astronomy, MHD flow meters, and lubrication.