Papers by Keyword: Thermal Radiation

Abstract: This study investigates the steady magnetohydrodynamic flow of the Walter-B ternary nanofluid (composed of water-ethylene glycol (WEG) base fluid with graphene, alumina, and titanium dioxide nanoparticles) over a nonlinear stretching sheet, incorporating the effects of cross-diffusion, couple stress, and viscous dissipation. Using similarity transformations, the governing equations are converted to ordinary differential equations and solved numerically with MATLAB's bvp4c solver. A Bayesian-regularized artificial neural network (BRANN) is developed to predict skin friction, Nusselt, and Sherwood numbers with R² > 0.99 accuracy. Results reveal that fluid velocity decreases with increasing couple stress but enhances with the Deborah number and Darcy parameter, while temperature rises with the Eckert and Dufour numbers. Concentration profiles decline with chemical reaction but grow with the Soret number. Entropy generation intensifies with Brinkman and Biot numbers, whereas the Bejan number shows opposite behavior. Empirical correlations for skin friction, Nusselt, and Sherwood numbers are developed, showing a 6.3% rise in skin friction with the Forchheimer number and a 13.14% improvement in heat transfer with thermal radiation. This work provides critical insights for thermal management systems, leveraging machine learning to optimize ternary nanofluid flows in porous media under cross-diffusion effects.

Abstract: The focal concern of this study is to examine the behaviour of bio-convective flow featuring micropolar nanofluids over an inclined permeable stretching surface while considering the influence of radiative activation energy. This investigation addresses the complex interplay of factors such as biological activity, convective heat and mass transfer, unique attributes of micropolar fluids, the dynamics of nanofluids, and radiative effects. This analysis employed Buongiorno’s model, considering thermal radiation and activation energy on the bioconvective flow of micropolar nanofluids over an inclined stretching surface. Some suitable similarity variables were used to obtain a set of non-linear differential equations from the initial partial differential equations which were then solved numerically using the Runge-Kutta Fehberg method along with shooting technique. The effects of some physical parameters were examined on the velocity, temperature, concentration, and microorganism density profiles of the flow. The result revealed that each increase in the heat source/sink, thermal radiation, thermophoresis, and Brownian motion lead to a corresponding increase in the thermal boundary layer; activation energy increased the concentration while Peclet number and bioconvective Lewis number declined the microorganism density profile. Insights gleaned from this study can find applications in biomedical fields. Understanding the behavior of bio-convective nanofluids has implications for controlled heat transfer in medical applications like hyperthermia treatments or targeted drug delivery, thereby impacting patient care.

Abstract: This paper studies the two-dimensional unsteady incompressible Ag-water and CuO-water nanofluid flow in a semi-porous expanding-contracting channel in the presence of thermal radiation effect. The continuity equation, Navier-Stokes equation, and energy equation governing the model are transformed into a set of non-dimensional ordinary differential equations using appropriate transformations. These dimensionless governing equations are solved using power series with the aid of the Hermite-Padé approximation method. The influences of physical parameters such as Reynolds number, expansion ratio, solid volume fraction, Prandtl number, Magnetic parameter, and shape factor are depicted in velocity and temperature profiles. Moreover, the average Nusselt number and skin friction coefficient are also investigated with the effect of Reynolds number, solid volume fraction, and expansion ratio. It is observed that the heat transfer rate decreases significantly as the shape factor increases.

Abstract: In this article, the heat transfer and flow pattern characteristics are discussed in the proximity of convective boundary condition for three kinds of nanoparticles, namely gold, Platinum and magnetite with three different shapes, namely spherical, platelets, and lamina. Here water is taken as a base liquid. The thermal radiation impact is assumed into account. The partial differential equations are shifted into ordinary differential equations by applying an acceptable transformation and then exact solutions are acquired by promoting the Laplace transform technique. Solid volume fraction is fluctuated as 5%, 10%, 15%, and 20%. The variations of nanoliquid motion and heat transfer are displayed graphically as well as the numerical values of skin friction and rate of heat transfer at the plate are displayed in tabular pattern. In particular, the liquid motion as well as the heat transfer is least for lamina type nanoparticles, medium for platelet type nanoparticles, and greatest for spherical type nanoparticles. Moreover, the skin friction escalates and the rate of heat transfer declines for three types of nanoliquids in three distinct shapes with the progress of time. This report can be further utilized to authenticate the effectiveness of acquired mathematical results for another sophisticated nanoliquid problems.

Abstract: Entropy generation minimization is a method that helps to improve the efficiency of real processes and devices. This study investigates the heat transfer in an electrically conducting Casson fluid flow between parallel plates under the influence of thermal radiation and convective boundary conditions. The thermodynamics first and second laws were employed to examine the problem. The present study provides a fast convergent method on the finite parallel plates, namely the Optimal Homotopy Analysis method (OHAM) and Collocation Method (CM) are used to analyzes the fluid flow, heat, transport. The impacts of governing parameters on Casson flow velocity, temperature profile, local skin friction, and Nusselt number were analysed. The obtained solutions were used to determine the heat transfer irreversibility and bejan number of the model. The method employed in this paper offers excellently convergence solutions with good accuracy. The results of the computation show that the effect of thermophysical properties such as thermal radiation parameter, suction/injection parameter, magnetic field parameter, radiation parameter, and Eckert number has a significant influence on Skin friction coefficient (Cf) and local Nusselt number (Nu) when compared to the Newtonian fluid. The application of this work can be found in polymer synthesis, metallic processing, and electromagnetic crucible systems.

Abstract: For the first time, the time dependences of the temperature of aluminum, zinc and zinc-aluminum alloys alloyed with II A group elements under spontaneous cooling mode were obtained; an anomalous course and two characteristic times of the cooling process were found, and their mechanism was explained; the temperature dependence of the thermophysical properties of the investigated metals and alloys was established; the temperature dependence of the coefficients of convective heat transfer and radiation of Al, Zn and Zn55Al and Zn5Al alloys was experimentally determined; the influence of the concentration of II A group elements and temperature on the heat capacity and thermodynamic functions of Zn55Al and Zn5Al alloys was revealed.

Abstract: This Paper contributes heat transfer phenomena in mixed convection flow of Siskoferronanofluidover a porous surface in the presence of a temperature gradient heat sink with prescribed heatflux. The effect of viscous dissipation and thermal radiation on the flow field is also taken in to consideration. The three types of ferromagnetic particles Nickel Zinc ferrite (Ni–ZnFe₂O₄), ManganeseZinc ferrite (Mn₁/2Zn₁/2Fe₂O₄) and Cobalt ferrite (CoFe₂O₄) are considered with water (H₂O)and Ethylene Glycol (C₂H₆O₂) as conventional base fluids. The RungeKuttaFehlberg method of numerical methodology is used to solve momentum and energy equations. With the help of graphs andtables, the effect of various associated physical parameters on the velocity, temperature, Skin frictioncoefficient and Nusselt number is studied. The present results indicate that the heat transfer rate ofEthylene Glycol based Siskoferronanofluid is higher than that of water based fluid and also waterbased Siskoferronanofluid reduces shear stress of the fluid flow rapidly than Ethylene glycol basedfluid. The accuracy of the results comparison table is validated with the current data.

Abstract: The influence of velocity slip and thermal radiation effects on the magnetohydrodynamic hybrid Cu-Al₂O₃/water nanofluid flow over a permeable stretching sheet is reported in this paper. The similarity transformation is adopted to reduce the partial differential equations to the ordinary differential equations. Exact analytical method is implemented to solve the problem. Maple program is used to facilitate the calculation process. The new additional effects which are the velocity slip and thermal radiation effects are considered towards the model to scrutinize the impacts. The effects of various parameters towards the velocity and temperature profiles are demonstrated through graphs, meanwhile the skin friction coefficient and the local Nusselt number are exhibited through the tabulation of data. The existence of velocity slip reduced the velocity profile but enhanced the temperature profile. The thermal radiation effect has increased the temperature profile. The heat transfer rate are enhanced for the case of hybrid nanofluid compared to the mono nanofluid.

Abstract: 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 4^th and 5^th 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.

Abstract: In this paper, a fractional relaxation model is studied to determine the effect of heat transfer and magnetic field on the blood flow. The flow is due to an oscillating periodic pressure gradient and body acceleration. We apply Laplace transform as well as finite Hankel transform to obtain the closed form solutions of the velocity and temperature distributions of the fractional time partial differential equations. Effect of the fluid flow parameters are shown graphically with changes in the ordinary model as well as the fractional parameters. The analysis shows that the fractional derivative is an excellent tool which gives remarkable change in controlling temperature and blood flow. The analysis depicts graphically, that in the presences of strong applied (exterior) magnetic field, reduces the temperature and blood flow velocities, which is appropriate to avoid tissues damage during treatment. In addition, it is seen that some of the aforementioned parameters influenced the fluid flow profiles in increasing and decreasing fashion which is interpreted as useful to the study.