Heat Transmission Rate Research Articles

A Generalized Two‐Phase Free Convection Flow of Dusty Jeffrey Fluid between Infinite Vertical Parallel Plates with Heat Transfer

In blood flow and fluid mechanics, Jeffrey fluid has a vital role because of its viscoelastic characteristics. The application of Caputo–Fabrizio time‐fractional derivatives for dusty‐type Jeffrey fluid is discussed in this article. The concept of free convection flow of dusty Jeffrey fluid between infinite vertical parallel static plates is generalized. Free convection and buoyant force produce the flow. Furthermore, the fluid contains homogeneous dispersion of all spherical dust particles. Heat transmission is therefore taken into account for free convection. Nondimensional variables are used to write the dusty Jeffrey fluid classical model in dimensionless form. Also, the dimensionless model is transformed into a generalized dusty Jeffrey fluid model via a fractional derivative. Using the finite sine and Laplace method, the governing equations of the generalized dusty Jeffrey fluid model have been solved exactly. Numerical computation is used to study the physics of velocity and temperature profiles for a variety of embedded parameters. The collected results are discussed in detail and are shown graphically in this report. Mathcad‐15 is used to plot the graphical outcomes for Jeffrey fluid, dust particle, and temperature profiles. Furthermore, skin friction and the Nusselt number are calculated. Table demonstrates how the rate of heat transmission reduces as the Peclet number’s value rises. Similarly, Table demonstrates that skin friction increases as the fractional parameter rises. By increasing the dusty Jeffrey fluid parameter λ, both velocity profiles are retarded.

Heat transfer analysis in fin and tube exchanger using CFD

The designs of fine tubes and thermal exchangers rely on the fabrication of copper and aluminum fin and tube heat exchangers. The heat was regulated through copper tubes and pipes by flowing water. The major objective of this work will be to enhance the rate of heat transmission by altering the existing tube and finish. The copper U-tube was replaced with the spline fin in the heat exchanger in this project. Pressure drop, speed, and heat transfer properties of the heat exchanger were evaluated using solid works and the study was conducted using computer fluid dynamics (CFD). From the results, it has been determined that the improvement of thermal transfer rate and efficiency in spline fin is up to 5 percent higher than the flat fin and also increases pressure and the higher pumping power in a heat exchanger by placing fluid within the fin through cross-flow.

Spectral‐quasi‐linearization method and multiple regression analysis of reiner‐philippoff fluid flow

AbstractIn this paper, the flow and heat transmission of Reiner‐Philippoff fluid (RPF) past a stretchable sheet is investigated theoretically and analyzed by using the numerical and statistical tools. A set of similarity transformations is used to non‐dimensionalize the governing equations. These expressions are numerically evaluated by employing the Spectral‐Quasi‐Linearization Method (SQLM). The numerical values are validated with the published results, and an excellent agreement is noticed in limiting cases. The results are presented graphically for different cases of fluids such as dilatant, Newtonian and pseudo‐plastic fluids for various physical parametric values include Bingham number, thermal buoyancy parameter, inclination angle parameter. Further, the behavior of fluid velocity and its temperature profiles are discussed within the boundary layer regime. Multiple regression process is used to analyze the results of the heat transmission rate and skin‐friction coefficient against distinct physical parametric values. It is observed that the dilatant fluid and pseudo‐plastic fluid show a diverse behavior as Bingham's number increases. With the enhancement in the inclination angle parameter, the fluid temperature risen for dilatant, pseudoplastic, and Newtonian fluids. This type of flow model over the stretching sheet has gained eminent importance in fluid dynamics due to their enormous applications in engineering and environment such as drawing of plastic sheets, metal and polymer extrusion, liquid coatings on photographic films, and so forth.

Enhanced Solar Air Heaters For Crop Drying

Solar air heaters are placed on farms to provide heat for the drying of grain and crop harvesting and harvesting. The results of the thermal study showed that solar air heaters are capable of providing a sufficient increase in air temperature under the majority of crop drying circumstances studied. The restricted thermal capacity of air, as well as the low heat transfer coefficient between the absorber plate and the air flow via the ducting system, both contribute to the overall thermal efficiency of solar air heaters. Solar air heaters must be more efficient in order to be more affordable. This may be accomplished by increasing the heat transfer coefficient between the absorber plate and the air flow passing through the duct. More heat transfer coefficients can be increased by using either active or passive approaches. In most situations, it may be cost-effective to use solar air heaters and incorporate artificial roughness on the absorber plate. The rate of heat transmission from the solar air heater’s duct to the fluid flow may be increased by creating artificial roughness on the surface of the duct. The study focused on several roughness element geometries for solar air heater ducts, and the results indicated that there is a link between the two. This paper attempts to find ways to artificially increase the heat transfer capacity of solar air heaters’ ducts by using element geometries which have been utilised in solar air heaters’ heat transfer devices.

Enhanced Solar Air Heaters for Crop Drying

Solar air heaters are placed on farms to provide heat for the drying of grain and crop harvesting and harvesting. The results of the thermal study showed that solar air heaters are capable of providing a sufficient increase in air temperature under the majority of crop drying circumstances studied. The restricted thermal capacity of air, as well as the low heat transfer coefficient between the absorber plate and the air flow via the ducting system, both contribute to the overall thermal efficiency of solar air heaters. Solar air heaters must be more efficient in order to be more affordable. This may be accomplished by increasing the heat transfer coefficient between the absorber plate and the air flow passing through the duct. More heat transfer coefficients can be increased by using either active or passive approaches. In most situations, it may be cost-effective to use solar air heaters and incorporate artificial roughness on the absorber plate. The rate of heat transmission from the solar air heater's duct to the fluid flow may be increased by creating artificial roughness on the surface of the duct. The study focused on several roughness element geometries for solar air heater ducts, and the results indicated that there is a link between the two. This paper attempts to find ways to artificially increase the heat transfer capacity of solar air heaters' ducts by using element geometries which have been utilised in solar air heaters' heat transfer devices.

A strategy for enhancing heat transfer in phase change material-based latent thermal energy storage unit via nano-oxides addition: A study applied to a shell-and-tube heat exchanger

Due to the scarcity of data on the industrial use of energy storage technology based on material phase change (PCM), a complete computational assessment is done in this work, where a nano-PCM technique is used to enhance the thermal energy storage in a big-scale shell-and-tube heat exchanger. Four high thermal conductive nano-oxides (i.e., Al2O3, MgO, SiO2, and SnO2) are added at various concentrations (1–5% v/v) into the PCM (i.e., paraffin RT82). A two-dimensional mathematical model is used to study the produced nano-PCM systems' heat transfer and melting rate. The model accurately predicted the PCM-melting data's observed behavior, showing that it is adequate for simulating PCM problems. The addition of nano-oxides, for up to 5%, in the PCM solid matrix dramatically enhances heat transmission and melting rate during the first melting stage. However, after a long melting period, the melting performance of the nano-PCMs decreased and became equivalent to that of the pure PCM.Furthermore, increasing the concentration of nanoparticles from 1 to 5% did not significantly improve the temperature and liquid fraction evolutions for the four studied nano-PCMs. Therefore, the use of nano-PCMs in the adopted LTES unit can effectively improve heat recuperation and melting rate, but only for a short charging time during which a part (up to 60%) of the PCM's latent heat is recovered. Consequently, the present paper's data is considered a guideline for increasing the efficacy of thermal energy storage in big-scale shell-and-tube heat exchangers using nano-PCM technology.

Unsteady shear-thinning behaviour of nanofluid flow over exponential stretching/shrinking cylinder

This study aims to explore the significance of wall-stress and rate of heat transmission for the unsteady shear-thinning behaviour of nanofluid flow over exponential stretching/shrinking cylinder. Drag force, heat transmission rate, Weissenberg number, stretching/shrinking velocity rate and unsteadiness are scrutinized under the influence of concentration of nanoparticles to understand the behaviour of the fluid for the engineering and industrial interests. The problem is analyzed by using Buongiorno model and developed a non-linear system of PDEs in cylindrical coordinates. The governing non-linear system of PDEs of unsteady shear-thinning behaviour for nanofluid over exponential stretching/shrinking cylinder is simplified into ODEs through the boundary layer approximation and appropriate similarity transformation. Furthermore, the solution of the developed system has been achieved by utilizing a new powerful numerical technique. A detailed discussion and illustrations of numerical solution for the rate of heat transmission, drag force, velocity profile, temperature profile and concentration of nanoparticles are demonstrated in the graphs and tables.

Mixed Convection Stagnation Point Flow of a Hybrid Nanofluid Past a Permeable Flat Plate with Radiation Effect

This article focuses on the stagnation point flow of hybrid nanofluid towards a flat plate. The cases when the buoyancy forces and the flow are in the opposite direction and the same direction are discussed. The effect of radiation and suction is also taken into account. The similarity transformations are used to convert the partial differential equations into nonlinear ordinary differential equations. These equations are computed numerically via the bvp4c function in MATLAB software. A comparison with the previously published articles is carried out, where an outstanding agreement is observed. The dual solutions exist in the case of opposing flow (λ<0) and the suction parameter S>0.6688. Meanwhile, only unique solutions exist in the case of assisting flow (λ>0). The existence of dual solutions leads to stability analysis. From the analysis, the first solution is confirmed as a stable solution. Furthermore, the heat transmission rate increases, while the skin friction coefficient decreases as the radiation rate increases. An increase in the radiation rate from 0 (no radiation) to 1.0 increases the heat transmission rate by 5.01% for water, 4.96% for nanofluid, and 4.80% for hybrid nanofluid. Finally, it is worth mentioning that the present study yields new and original results. This study has also not been done by other researchers, indicating its novelty.

Heat transfer analysis for EMHD peristalsis of ionic-nanofluids via curved channel with Joule dissipation and Hall effects.

The objective of this research is to study the combined influences of applied electric and magnetic fields on the two-phase peristaltic motion of nanofluid through a curved channel. A two-phase model of a nanofluid, Maxwell's model of thermal conductivity [1], and no-slip velocity and thermal boundary conditions have been used in this study. Hall effects, Joule heating (due to magnetic and electric fields), and viscous heating aspects are under consideration. Governing equations for the present flow configuration have been modeled and simplified by enforcing the lubrication scheme. Debye-Huckel approximation is used to obtain the analytical solution of the electric potential function (Poisson-Boltzmann equation). Resulting expressions are solved numerically through the NDSolve command in Mathematica and plotted in order to understand the effects of different dimensionless parameters on the temperature, stress, heat transmission rate, and fluid's velocity. Graphical results demonstrated that the thermal transmission rate is augmented by increasing the Hartmann number, Brinkman number, and Debye-Huckel parameter while decreases for zeta potential ratio, Joule dissipation parameter, and electro-osmotic velocity. A decrease in axial velocity is noted near the lower wall for higher values of [Formula: see text].

Numerical Simulation of Hybrid Nanofluid Mixed Convection in a Lid-Driven Square Cavity with Magnetic Field Using High-Order Compact Scheme.

In this study, the energy transference of a hybrid Al2O3-Cu-H2O nanosuspension within a lid-driven heated square chamber is simulated. The domain is affected by a horizontal magnetic field. The vertical sidewalls are insulated and the horizontal borders of the chamber are held at different fixed temperatures. A fourth-order accuracy compact method is applied to work out the vorticity-stream function view of incompressible Oberbeck–Boussinesq equations. The method used is validated against previous numerical and experimental works and good agreement is shown. The flow patterns, Nusselt numbers, and velocity profiles are studied for different Richardson numbers, Hartmann numbers, and the solid volume fraction of hybrid nanoparticles. Flow field and heat convection are highly affected by the magnetic field and volume fraction of each type of nanoparticles in a hybrid nanofluid. The results show an improvement of heat transfer using nanoparticles. To achieve a higher heat transmission rate by using the hybrid nanofluid, flow parameters like Richardson number and Hartmann number should be considered.

Radiative Non-Coaxial Rotating Flow for Viscous Fluid over Accelerated Disk with MHD and Porosity Effects

An analytical solution to analyze the effects of radiation, magnetic, and permeability in an accelerating non-coaxial rotation phenomenon is not yet reported in the previous studies. Therefore, a radiative mixed convection flow for non-coaxial rotating MHD viscous fluid in a porous medium past an accelerated disk is studied. The fluid motion in this problem is induced by two sources which are rotating and buoyancy force. The dimensional coupled differential equations subjected to initial and accelerated boundary conditions are transformed to the dimensionless equations by utilizing appropriate dimensionless variables. The Laplace transform technique is applied to generate the closed form analytical solution for this problem. The impacts of Prandtl number, Grashof number, radiation, magnetic, porosity, and accelerated parameters on the temperature and velocity fields are illustrated graphically. The velocity and temperature profiles satisfy both the initial and boundary conditions, and the present results are found in accordance to the published work. The velocity is improved with the assistance of acceleration, radiation and porosity, while the implementation of magnetic field causes the opposite effect. Increasing radiation leads to the growth of the thermal boundary layer as well as reducing the heat transmission rate. This result can significantly contribute to the designing of heating systems because the imposition of radiation able to sustain an environment for a specific temperature. The obtained analytical solution can be used to check the correctness of the solution obtained from the numerical and experimental studies.

Micropolar fluid past a convectively heated surface embedded with nth order chemical reaction and heat source/sink

The objective of the present article is to investigate an incompressible micropolar Prandtl fluid flowing over a porous stretching sheet with the inclusion of effects like exponential temperature-dependent heat source, higher-order chemical reaction viscous dissipation, nonlinear thermal radiation, and multiple convective surface boundary conditions. The nonlinear partial differential equations (PDEs) for momentum, energy, micro-rotation, and concentration are discussed. These PDEs are converted into ordinary differential equations (ODEs) by utilizing suitable variables and then tackled with the utilization of the nonlinear shooting method. For the numerical assessment of upcoming results comparison with already existing literature has been taken. It is canvassed that by augmenting the microrotation parameter, a boost in the angular velocity profile is seen. Moreover, The higher order of reactivity upsurges the heat transmission rate, whilst the mass convection enhances the concentration size. This gives the current model potency as a potential application in clean engine lubricants and coolant industrial liquids under the same constraints.

Numerical study of melting heat transfer in stagnation-point flow of hybrid nanomaterial (MWCNTs+Ag+kerosene oil)

PurposeThe purpose of this study is to analyze hybrid nanofluid (MWCNTs+Ag+Kerosene oil) over a stretched cylinder. Flow analysis is carried out in presence of stagnation-point. Features of heat transport are examined via melting conditions.Design/methodology/approachGoverned expression (partial differential equations) for flow and heat transfer are transmitted into ordinary differential equations (ODEs) via applying adequate transformations. For solutions development shooting method (bvp4c) is used on these non-linear coupled ODEs.FindingsComparative observation among hybrid nanofluid (MWCNTs+Ag+Kerosene oil), basefluid (kerosene oil) and nanofluid (MWCNTs+Kerosene oil) are performed. Influences of physical parameters on heat transfer rate, velocity, skinfriction coefficient and temperature are visualized graphically. Higher values nanoparticle volume fractions, curvature parameter, melting parameter and velocity ratio parameter lead to intensification in the velocity profile. The temperature of the fluid reduces with higher values nanoparticle volume fractions, curvature parameter and melting parameter. The surface friction coefficient is minimized via a higher melting parameter and velocity ratio parameter. Heat transmission rate intensifies with velocity ratio parameter, nanoparticle volume friction and curvature parameter while it reduces gradually with larger melting parameter. During comparative study performance of hybrid nanomaterial (MWCNTs+Ag+Kerosene oil) is outstanding and is proceeded by nanomaterial (MWCNTs+ Kerosene oil) and basefluid (kerosene oil).Originality/valueIn the presented study authors have analyzed the flow of hybrid nanomaterial (MWCNTs+Ag+Kerosene oil) by a stretching cylinder. The further cylinder is subjected to stagnation point and melting condition. The authors believe that all the consequences of the presented study and numerical technique (bvp4c) are original and not published before.

Curvilinear flow of micropolar fluid with Cattaneo–Christov heat flux model due to oscillation of curved stretchable sheet

Abstract This paper aims to investigate the transfer of heat phenomenon in a hydromagnetic time dependent flow of micropolar fluid across an oscillating stretchable curved surface by using the Cattaneo–Christov heat flux model, which considers thermal relaxation time. An elastic curved surface that stretches back and forth causes the flow situation. The flow equations are derived as nonlinear partial differential equations by incorporating a curvilinear coordinates system, which is then solved analytically via the homotopy analysis method (HAM). The accuracy of the derived analytical results is also examined by using a finite-difference technique known as the Keller box method, and it is found to be in strong agreement. The influences of various physical characteristics such as material parameter, magnetic parameter, thermal relaxation parameter, a dimensionless radius of curvature, Prandtl number and ratio of surface’s oscillating frequency to its stretching rate parameter on angular velocity, fluid velocity, pressure, temperature, heat transmission rate, and skin friction and couple stress coefficient are depicted in detail with the help of graphs and tables. Furthermore, for the verification and validation of the current results, a tabular comparison of the published data in the literature for the case of flat oscillating surface versus curved oscillating surface is carried out and found to be in good agreement.

Axisymmetric hybrid nanofluid flow with heat and mass transfer amongst the two gyrating plates

AbstractThe combined effects of magnetic and electrohydrodynamic on the water‐based iron oxide and CNTs hybrid nanoliquids flow between two rotating plates are examined. The influence of electro‐magneto‐hydrodynamics on the mass and heat transmission characteristics is the main aim of this study. The hybrid nanofluid is synthesized using water as a base fluid in the (Iron oxide) , single and multi‐walled (SWCNTs/MWCNTs) carbon nanotubes (CNTs). The flow model has been arranged in form of PDEs, which are reduced into the system of dimensionless differential equations through a similarity approach. The differential equations are further treated with HAM to get analytic results. The impact of the Reynolds number, magnetic, electric and rotation parameters, on the drag force, mass flux and heat transmission rate has been scrutinized and discussed. The arithmetic consequences are carried out for Nusselt number, Sherwood number and drag force. The heat transmission has been considered to increase with the Reynolds number, magnetic constraint and electric parameter. The electric parameter improving the momentum boundary layer and drop the thermal boundary layer. The outcomes are compared with the existing literature and a closed agreement has found.

Numerical approach towards gyrotactic microorganisms hybrid nanoliquid flow with the hall current and magnetic field over a spinning disk

The article explores the effect of Hall current, thermal radiation, and magnetic field on hybrid nanofluid flow over the surface of a spinning disk. The motive of the present effort is to upgrade the heat transmission rate for engineering and industrial purposes. The hybrid nanofluids as compared to the conventional fluids have higher thermal properties. Therefore, in the present article, a special class of nanoparticles known as carbon nanotubes (CNTs) and iron ferrite nanoparticles are used in the base fluid. The system of modeled equations is depleted into dimensionless differential equations through similarity transformation. The transform equations are further solved through the Parametric Continuation method (PCM). For the parametric study, the physical parameters impact on velocity, energy, mass transmission, and motile microorganism’s concentration profiles have been sketched. The obtained results are compared with the existing literature, which shows the best settlement. It concluded that the heat transmission rate reduces for Hall current and rises with radiative parameter. The results perceived that the addition of CNTs in carrier fluid is more efficacious than any other types of nanoparticles, due to its C–C bond. CNTs nanofluid can be more functionalized for the desired achievement, which can be utilized for a variety of applications by functionalization of non-covalent and covalent modification.

Zero-Energy Building Integrated Planning Methodology for Office Building Considering Passive and Active Environmental Control Method

The objective of this study is to derive a design methodology for a zero-energy building considering the energy production and consumption of the building. In order to establish the design methodology, various factors affecting the energy production and consumption of the building are derived, and the effect of the heat transmission rate, the surface to volume ratio (S/V ratio), the location and the orientation of the building are analyzed by simulation method. As a result, the S/V ratio and the heat transmission rate are the most important factors in the central region of Korea where consumes large amounts of heating and cooling energy. This is because the final energy consumption varies depending on the heat loss through the envelope. It was confirmed that solar power generation is the most important factor in the southern regions of Korea where the energy consumption is relatively small. The final energy consumption varies depending on the solar power generation in these areas. Therefore, when designing a zero-energy building, the zero-energy of the building can be achieved by using the design methodology established in this study.

Mathematical Analysis of Two Phase Saturated Nanofluid Influenced by Magnetic Field Gradient

Nanofluids are composed of nano-sized particles dispersed in a carrier liquid. The present investigation’s aim is to examine theoretically the magneto-thermomechanical coupling phenomena of a heated nanofluid on a stretched surface in the presence of magnetic dipole impact. Fourier’s law of heat conduction is used to evaluate the heat transmission rate of the carrier fluids ethylene glycol and water along with suspended nanoparticles of a cobalt–chromium–tungsten–nickel alloy and magnetite ferrite. A set of partial differential equations is transformed into a set of non-linear ordinary differential equations via a similarity approach. The computation is performed in Matlab by employing the shooting technique. The effect of the magneto-thermomechanical interaction on the velocity and temperature boundary layer profiles with the attendant effect on the skin friction and heat transfer is analyzed. The maximum and minimum thermal energy transfer rates are computed for the H2O-Fe3O4 and C2H6O2-CoCr20W15Ni magnetic nanofluids. Finally, the study’s results are compared with the previously available data and are found to be in good agreement.

Von-Karman rotating flow in variable magnetic field with variable physical properties

The steady incompressible slip flow with convective heat transport under the impact of a variable magnetic field has been taken into an account over a revolving disk. The temperature dependent viscosity, density, and thermal conductivity has been scrutinized. The obtained system of nonlinear differential equations governing the induced magnetic field, steady flow, and heat transmission has put down in polar cylindrical coordinates. The subsequent arrangement of nonlinear PDEs are subside into dimensionless system of ordinary equations, while making use of similarity abstraction. The modeled equations are tackled through Homotopy Analysis Method (HAM). The skin fraction coefficient, heat transmission rate, and Nusselt number (skin effects coefficient) are deliberated. From the results, It can be perceived that the slip factor effectively controls the heat and the flow characteristics. The influence of dimensionless numbers such as Batcheler number [Formula: see text] and magnetic strength [Formula: see text] and [Formula: see text] are explored and shown graphically. Further the out-turn of Prandtl number, relative temperature difference, suction parameter, and slip factor on the temperature fields and velocity profile are discussed.

Navier slip and suction/injection effects on oscillatory flow of nanofluid with fluid-particle interaction in a channel

In this paper, the slip and porosity effects on the channel walls are studied for the oscillatory flow of heat-absorbing/generating dusty nanofluid flowing through a porous medium. The channel is vertical and exposed to the transverse magnetic field and thermal radiation. The base fluid is water with silver as nanoparticles. The basic equations of the flow problem, which appeared to be dimensional, are remodelled in the dimension-less form with the help of non-dimensional variables. The obtained equations are solved analytically using the variable separable method. The graphs are presented to show the impact of these parameters on the flow fields, skin friction, heat transmission rate and discussed in detail. Results reveal that the flow velocities of fluid and particles for suction are greater than in the case of injection. The fluid velocity upsurges with the improved values of the velocity slip parameter.