Influence Of Thermal Radiation Research Articles

Hall and ion slip impacts on unsteady MHD free convective rotating flow of Jeffreys fluid with ramped wall temperature

The influence of thermal radiation, Hall and ion-slip impacts on the unsteady MHD free convective rotating flow of Jeffreys fluid past an infinite vertical porous plate with the ramped wall temperature has been investigated. The Laplace transform technique is utilized to accomplish the analytical solutions of governing equations with initial and boundary conditions. The significant performances of velocity and temperature are acquired to recognize the physical characteristics through a few implanted parameters and are revealed graphically with two kinds of cases ramped wall temperature and isothermal plate. The research phrases of engineering curiosity for skin friction and Nusselt number are originated for mutually ramped wall temperature and isothermal plate. Also it is plotted the velocity vector and discussed the stream lines with reference to pertinent parameters. This is monitored with the intention of that, the enormity of velocity and temperature distributions in favour of isothermal plate are forever superior to the ramped wall temperature.

Radiative Effects on Unsteady MHD Couette Flow through a Parallel Plate with Constant Pressure Gradient

In this paper, the unsteady MHD Couette flow through a porous medium of a viscous incompressible fluid bounded by two parallel porous plates under the influence of thermal radiation and chemical reaction is investigated. A uniform suction and injection are applied perpendicular to the plates while the fluid motion is subjected to the constant pressure gradient. The transformed conservation equations are solved analytically subject to physically appropriate boundary conditions by using the Eigenfunction expansion technique. The influence of some emerging non-dimensional parameters namely, pressure gradient, suction parameter, radiation parameter, and Hartman number are examined in detail. It is observed that the primary velocity is increased with increasing pressure gradient while the increase in radiation parameter leads to adecrease in the thermal profile of the flow.

Featuring the radiative transmission of energy in viscoelastic nanofluid with swimming microorganisms

This article highlights the influence of thermal radiation, inclined magnetic field, and stratification on the third-grade nanofluid with swimming gyrotactic microorganisms. The fluid is flowing past a horizontal cylinder exposed to an inclined magnetic field. The boundary layer system of equations is reconstructed into ordinary differential equations using similarity transformations. The system of equations is resolved using the Optimal Homotopy Analysis Method (OHAM) and the results are visualized numerically and graphically. Physical properties have been taken into consideration and the repercussions of different parameters on these properties are analyzed through contour plots. The following upshots are prominent: (i) radiation augments diffusive energy to the system enhancing the temperature along with the heat transfer rates, (ii) the more inclined magnetic field causes more decrease in velocity (iii) the bioconvective aspect introduced due to the addition of microorganisms altered the transfer rates of microorganisms positively, and (iv) nanoparticles evidently brought down the concentration through Brownian motion effects and the overall influence of these particles hindered mass transport rates.

Mixed Convection in MHD Water-Based Molybdenum Disulfide-Graphene Oxide Hybrid Nanofluid through an Upright Cylinder with Shape Factor

In this work, water is captured as regular fluid with suspension of two types of hybrid nanoparticles, namely molybdenumdisulfide (MoS2) and graphene oxide (GO). The impact of Lorentz’s forces on mixed convective boundary-layer flow (BLF) is studied through an upright cylinder under the influences of thermal radiation. The shape factor is also assessed. The mathematical model for hybrid nanofluidis developed and, by implementing suitable similarity variables, the leading partial differential equations (PDEs) are altered into a non-linear ordinary differential equations (ODEs) system and then resolved through a bvp4c solver. The penetrations of varied parameters, such as thermal radiation, nanomaterials shapes (bricks, platelets, bricks and cylinders), magneto-hydrodynamics (MHD), and ratio parameters on the temperature and fluid velocity, along with the skin friction and the Nusselt number, are typified qualitatively via sketches. The opposing flow, as well as the assisting flow, is considered. The results indicate that the impact of hybrid nanofluid (HBNF) on the velocity and the temperature is more than nanofluid (NF). It is also scrutinized that the blade-shaped nanomaterials of hybrid nanofluid have a maximum temperature and brick-shaped nanomaterials have a low temperature. In addition, the friction factor and the heat transport rate decline due to the magnetic parameter and increase due to the shape factor. Moreover, the radiation uplifts the velocity and temperature, while the free stream Reynolds number declines the velocity and temperature. Finally, a comparison with available results in the literature are made and found in an excellent way. The ranges of constraints in this research are considered as: 0.01 ≤ λ ≤ 0.2 , 0 ≤ M ≤ 4 , 0 ≤ α ≤ 1.5 , 0 ≤ R d ≤ 1 , 1 ≤ Re a ≤ 3 , 0 ≤ ϕ 1 ≤ 0.1 and 0 ≤ ϕ 2 ≤ 0.003 .

Analytical study of transient counter-flow non-premixed combustion of biomass in presence of thermal radiation

Abstract In this study, the transient behavior of a counter-flow non-premixed combustion of dry biomass particles under thermal radiation was modeled analytically. Unsteady conservation equations for mass and energy transports are mathematically formulated in dimensional and dimensionless forms. Preheating, vaporization and reaction processes were considered as the main processes for combustion of the biomass particles. The derived analytical model was solved using an asymptotic technique. After validating our derived analytical model with experimental data, the counter-flow non-premixed combustion of dry lycopodium particles with air was investigated. First, the temporal evolutions of distributions of temperature and species mass fractions were presented and discussed. Also, the temporal changes of flame temperature and position were discussed. The influence of thermal radiation was found to be quantitatively other than qualitatively. Finally, the effects of key operating parameters, such as biomass particle diameter, and Lewis numbers of biomass and oxidizer, were studied. When the combustion process reaches steady state, for unity Lewis number, maximum values of flame temperature with and without the radiative heat losses are equal to 1650 K and 1910 K at t = 0.02 s , respectively.

MHD radiative nanofluid flow induced by a nonlinear stretching sheet in a porous medium

In this article, we numerically investigate the influence of thermal radiation and heat generation on the flow of an electrically conducting nanofluid past a nonlinear stretching sheet through a porous medium with frictional heating. The partial differential equations governing the flow problems are reduced to ordinary differential equations via similarity variables. The reduced equations are then solved numerically with the aid of Keller box method. The influence of physical parameters such as nanoparticle volume fraction ϕ, permeability parameter K, nonlinear stretching sheet parameter n, magnetic field parameter M, heat generation parameter Q and Eckert number Ec on the flow field, temperature distribution, skin friction and Nusselt number are studied and presented in graphical illustrations and tabular forms. The results obtained reveal that there is an enhancement in the rate of heat transfer with the rise in nanoparticle volume fraction and permeability parameter. The temperature distribution is also influenced with the presence of K, Q, R and ϕ. This shows that the solid volume fraction of nanoparticle can be used in controlling the behaviours of heat transfer and nanofluid flows.

Influence of thermal radiation on thermogravitational convection in a tilted chamber having heat-producing solid body

The present work represents a numerical calculation methodology which allows predicting the convective-radiative energy transport in an inclined cavity having an energy-generating body. The surfaces of left and right walls of the chamber are cooled, whilst the upper and down borders are thermally insulated. A square shaped solid block placed in the central zone of the chamber. The finite volume technique is employed to solve the general equations. A parametric study is performed tacking into account the following parameters: thermal conductivity ratio k⁎ from 1 to 10, inclination angle of the cavity φ from 0 to π/2 and emissivity of the surfaces ε from 0 to 1. The impact of the present parameters on both temperature and flow fields, as well as on Nusselt numbers is studied. So, under the radiation energy transport the buoyancy-induced flow gets diminished. The results illustrated that the influence of the thermal radiation on overall thermal transmission becomes strong with surface emissivity of energy-producing solid body and walls.

Numerical study on forced convection in the exhaust problem using the spectral line-based weighted sum of gray gases model

In this work, influences of thermal radiation on forced convection in the Exhaust problem are effectively simulated by application of the spectral line-based weighted sum of gray gases (SLW) model. The Exhaust problem includes an abrupt contraction in a horizontal channel. The working fluid of this problem is an air mixture with 10% CO2 and 20% H2O mole fractions. This mixture is regarded as an emitting, absorbing and non-scattering medium. In addition, the gray model is utilized to simulate the radiative medium based on total emissivity. Then, the findings of this model are compared with the results of SLW model as the main case to attain the error rate of gray model in simulating the Exhaust problem. The results clearly show the differences between the gray and SLW models to simulate the thermal behaviors are strongly dependent on the radiation-conduction parameter (25 ≤ RC ≤ 50) and wall emissivity (0 ≤ ɛw ≤ 1). In this regards, the gray model is unable predict the real results in many cases.

MHD Flow of Non-Newtonian Molybdenum Disulfide Nanofluid in a Converging/Diverging Channel with Rosseland Radiation

The steady two-dimensional flow of an incompressible non-Newtonian Molybdenum Disulfide nanofluid in the presence of source or sink between two stretchable or shrinkable walls under the influence of thermal radiation is investigated numerically. A generalized transformation is applied to convert the constructed set of partial differential equations (PDEs) into the system of non-linear coupled ordinary differential equations (ODEs). The obtained system of ODEs are solved by using Runge-Kutta 4th and 5th order. The influence of physical parameters, shrinking/ stretching parameter, Casson parameter, Hartmann number, Reynolds number, solid volume fraction, opening angle of the channel and radiation parameter on the velocity and temperature distribution are observed for converging and diverging channels. It is noticed that thermal boundary layer thickness is diminished for increased thermal radiation resulting in gradual temperature fall. The results also reveal that velocity and temperature profile both are elevated on raising the stretching parameter and Hartmann number. A comparative analysis is made out to validate the present results.

Entropy Generation and Consequences of MHD in Darcy–Forchheimer Nanofluid Flow Bounded by Non-Linearly Stretching Surface

Present communication aims to inspect the entropy optimization, heat and mass transport in Darcy-Forchheimer nanofluid flow surrounded by a non-linearly stretching surface. Navier-Stokes model based governing equations for non-Newtonian nanofluids having symmetric components in various terms are considered. Non-linear stretching is assumed to be the driving force whereas influence of thermal radiation, Brownian diffusion, dissipation and thermophoresis is considered. Importantly, entropy optimization is performed using second law of thermodynamics. Governing problems are converted into nonlinear ordinary problems (ODEs) using suitably adjusted transformations. RK-45 based built-in shooting mechanism is used to solve the problems. Final outcomes are plotted graphically. In addition to velocity, temperature, concentration and Bejan number, the stream lines, contour graphs and density graphs have been prepared. For their industrial and engineering importance, results for wall-drag force, heat flux (Nusselt) rate and mass flux (Sherwood) rate are also given in tabular data form. Outputs indicate that velocity reduces for Forchheimer number as well as for the porosity factor. However, a rise is noted in temperature distribution for elevated values of thermal radiation. Entropy optimization shows enhancement for larger values of temperature difference ratio. Skin-friction enhances for all relevant parameters involved in momentum equation.

Natural Convection and Thermal Radiation Influence on Nanofluids in a Cubical Cavity

Natural Convection and Thermal Radiation Influence on Nanofluids in a Cubical Cavity

Combined Mixed Convection and Radiation Heat Transfer in the Presence of Participating Medium in a Square Cavity with an Inside Heated Plate

The present paper analyses the interaction between thermal radiation and mixed convection inside a square vented enclosure containing a thin heated plate. The cavity walls are assumed to be diffuse, grey and opaque, while the working fluid is considered to be a radiatively absorbing, emitting and scattering medium. The main attention is focused on the effect of plate inclination angle and radiative parameters on the thermal field, fluid flow and heat transfer rate. The mixed convection governing equations are discretised using the finite volume method and are solved using the SIMPLE algorithm, whereas the solution of the radiative transfer equation is obtained using the discrete ordinate method (DO). Flow parameters such as Grashof number Gr and Richardson number Ri, and geometrical parameters like heated plate inclination are varied to show their impact on heat transfer enhancements. The effect of radiation parameters namely the radiation–conduction parameter RC and fluid optical thickness τ are also discussed while the walls emissivity and single scattering albedo were kept constant. The obtained results show that there is not a limited angle which improves heat transfer for all considered cases, but for every Gr and Ri value, there is a specific inclination which gives the most efficient rate of heat transfer, regardless of other considered parameters. The findings also highlight the influence of thermal radiation on heat transfer behaviour within the enclosure.

Application of CNT-based micropolar hybrid nanofluid flow in the presence of Newtonian heating

This research addresses the effects of Hall and ion slip in micropolar hybrid nanofluid in the presence of Newtonian heating. Furthermore, the influence of thermal radiation, Darcy–Forchheimer, viscous dissipation, and variable viscosity is discussed. Total entropy generation rate is calculated. Two distinct nanoparticles such as (SWCNT, MWCNT) used as a hybrid nanofluid. Built-in function bvp4c integrates the solution of simulated hydrodynamic boundary value problems. The effects on axial velocity, angular velocity, temperature field, concentration field, Bejan number, and entropy optimization of different flow field variables are displayed graphically. The nanoparticle fraction boosts the temperature field, Bejan number, and entropy generation, while the axial velocity and microrotation field reduces. Furthermore, the entropy generation enhances with higher the Brinkman number and variable viscosity parameter.

Unsteady Magneto hydrodynamic Boundary Layer Flow towards a Heated Porous Stretching Surface with Thermal Radiation and Heat Source/Sink Effects

Mathematical model of unsteady boundary layer flow and heat transfer is explored for analyzing the study of influence of thermal radiation on incompressible viscous electrically conducting fluid over continuous stretching surface embedded in a porous medium in the presence of heat source/sink. The scope of influencing parameters that describing phenomenon are determined and governing time dependent boundary layer equations are transformed to ordinary differential equations by using appropriate similarity transformation. Numerical computation of the problem was carried out by shooting iteration technique together with Runge-Kutta fourth order integration scheme. Effects of unsteadiness parameter, permeability parameter, magnetic parameter, thermal radiation parameter, Prandtl number and heat source/sink parameter on velocity and temperature profiles are computed and illustrated graphically, whereas local skin friction coefficient and local Nusselt number are represented numerically through tables. In nonmagnetic flow condition the result is found in concordance with earlier investigations.

Entropy generation in MHD Williamson nanofluid over a convectively heated stretching plate with chemical reaction

AbstractThis investigation focuses on the influence of thermal radiation on the magnetohydrodynamic flow of a Williamson nanofluid over a stretching sheet with chemical reaction. The phenomena at the stretching wall assume convective heat and mass exchange. The novelty of the present study is the thermodynamic analysis in the nonlinear convective flow of a Williamson nanofluid. The resulting set of the differential equations are solved by the homotopy analysis method. We explored the impacts of the emerging parameters on flow, heat, and mass characteristics, including the rate of entropy generation and the Bejan number through graphs, and extensive discussions are provided. The expressions for skin friction, Nusselt and the Sherwood numbers are also analyzed and explored through tables. It is concluded that the rate of mass transfer may be maximized with the variation of the Williamson and chemical reaction parameters. Moreover, the entropy generation rate and the Bejan number are augmented via increasing the Williamson parameter.

Dynamic Monitoring of RS and GIS Resources and Ecological Environment Based on High Temperature Materials

The dynamic monitoring and analysis of regional ecological environment is an important part of land use research, which can provide support for regional ecological environment and macro regulation of government departments. With the support of remote sensing technology (RS) and geographic information system (GIS), a land use dynamic monitoring system is established to obtain land use change information quickly, accurately and economically. In order to reduce the influence of thermal radiation, noise and vibration of high temperature material machinery on the measurement results in high temperature measurement environment, the paper proposed the measurement method of ultraviolet light high humidity thermal deformation and gray average method. In this paper, the algorithm of digital image correlation method and the establishment of high temperature measurement system are studied. A set of high temperature material mechanical digital image correlation system suitable for high humidity environment measurement is independently established and applied to the high humidity test of materials. The results show that the above comprehensive method can effectively improve the influence of thermal flow disturbance on system imaging in high humidity environment. Comprehensive analysis of regional ecological environment data shows that environmental quality is closely related to regional ecological environment. Meteorological conditions are one of the important factors affecting the environment, and the project of returning farmland to forest plays a vital role in improving the environment.

Combined Effects of Thermal Radiation and Magnetohydrodynamic on Peristaltic Flow of Nanofluids: Applications to Radiotherapy and Thermotherapy of Cancer

Background:Cancer is deadly to most of its patients. Consequently, researchers and modelers studies show that there are many ways to cure and destroy it. One of the effective ways is to inject the blood vessel close to the tumor with magnetic nanoparticles. Another way called the radiation therapy or radiotherapy, which eradicates cancer cells through high doses of radiation.Objective:This paper opts to investigate the influences of thermal radiation and variable electrical conductivity on peristaltic flow of Carreau Nanofluids. First order chemical reaction, Dufour and Soret effects are taken into consideration.Methods:The resulting system of partial differential equations is solved numerically with the aid of Parametric-NDSolve. Results for velocity, temperature and concentration distributions are obtained in the analytical two-dimensional and three-dimensional forms. The streamlines graphs are offered in the terminus, elucidating the trapping bolus phenomenon.Results:It has been found that thermal radiation is a decreasing function in the temperature of the fluid. As the temperature decreases, the diameter of the nanoparticles increases i.e., the volume of nanoparticle and its concentration increases and become more effective near tumor tissues.Conclusion:Radiotherapy and Thermotherapy are effective methods to cure and damage the tumor tissues.

Analytical approach for the steady MHD conjugate viscous fluid flow in a porous medium with nonsingular fractional derivative

This study investigates the unsteady magnetohydrodynamics (MHD) flow of a viscous fluid. The fluid is passing over a vertical plate through porous medium. Additionally conjugate effects of heat and mass transfer with ramped temperatures, slip effect and influence of thermal radiation in the energy equation are taken into account. The dimensionless fractional-order governing equations, in the Caputo–Fabrizio sense, are solved with the help of Laplace transformation. Moreover, semi analytical technique is used to investigate the velocity field. Some results which present in literature are recovered as limiting cases. Influences of different parameters on the velocity profiles for the case of f(t)=t and f(t)=sinωt are highlighted. The novelty of the manuscript is the use of the most recent definition of the non integer order derivative operator i.e. Caputo–Fabrizio derivative operator, the use of generalized boundary conditions in terms of general function f(t), from our general results, several particular cases for instance when f(t) is a linear or sinusoidal function could be recovered.

Magnetohydrodynamics natural convection of nanofluid flow over a vertical circular cone embedded in a porous medium and subjected to thermal radiation

In this paper, magnetohydrodynamics natural convection of nanofluid flow over a vertical circular cone immersed in a porous medium under the influence of thermal radiation is investigated using multi-step differential transformation method. The accuracies of the analytical solutions are established through the verifications of the results of the present study with the results of the numerical solutions and the past studies. The approximate analytical solutions are used to examine the impacts of cone angle, flow medium porosity, magnetic field, nanoparticles volume-fraction and shape on the flow and heat transfer behaviours of the Copper (II) Oxide-water nanofluid. It is hoped that this study will enhance better understanding of flow process for the design of flow and heat transfer equipment.

Peristaltic pumping in Buongiorno model nanofluids transport within flexible walls

Peristaltic pumping is a mechanism always takes place from lower pressure region to higher pressure region. The Buongiorno model nanofluid transport for peristaltic pumping within flexible walls has several many applications such as, urine transport between kidney and bladder, drug delivery in blood vessels etc. Several pharmacological delivery systems including industrial applications are the basic principle of peristaltic pumping in transport systems. In the current research work, Buongiorno model nanofluid is undertaken for the peristaltic pumping within flexible walls. The mechanism through an electrically conducting nanofluid warrants the effect of magnetic field. In addition to that, the influences of thermal radiation, Brownian motion, thermophoresis, and constant heat source/sink are deployed in the present investigation. The simplified nonlinear governing equations are solved numerically and the observations for the embodying parameters are displayed via graphs and tabular form. In particular situation the result shows a conformation with that of earlier investigations warrants carrying forward further investigation and the conclusive remarks are elaborated in the results and discussion section.