scholarly journals Development of Dynamic Model and Analytical Analysis for the Diffusion of Different Species in Non-Newtonian Nanofluid Swirling Flow

2021 ◽  
Vol 8 ◽  
Author(s):  
Auwalu Hamisu Usman ◽  
Noor Saeed Khan ◽  
Usa Wannasingha Humphries ◽  
Zahir Shah ◽  
Poom Kumam ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Activation Energy ◽  
Chemical Reactions ◽  
Swirling Flow ◽  
Local Density ◽  
Variable Thermal Conductivity ◽  
Arrhenius Activation Energy ◽  
Opposite Trend ◽  
Lower Disk ◽  
The Impact

The analysis is carried out to analyze the flow through double stretchable rotating disks with the theory of radiative Cross nanofluid under the influence of variable thermal conductivity, the Hall current, Arrhenius activation energy, and binary chemical reactions. The Buongiorno nanofluid model is adopted for the governing equations of the problem which are transformed into ordinary differential equations through similarity transformations and then solved using the homotopy analysis method. The impact of dimensionless parameters on all profiles and physical quantities is presented and discussed. The radial velocity of the two disks increases with their corresponding ratio stretching rate parameter and decreases with the Hall parameter and the bioconvection Rayleigh number. The heat transfer at the lower disk enhances with the variable thermal conductivity parameter, while at the upper disk, opposite trend is observed. Mass transfer increases with the chemical reactions and temperature difference parameters at the lower disk and decreases with Arrhenius activation energy, whereas an opposite trend is observed at the upper disk. The local density number is enhanced for the larger values of Peclet and Lewis numbers. The comparison of the present work with the published literature authenticates the validation of the present work.

scholarly journals Numerical simulation of variable thermal conductivity on 3D flow of nanofluid over a stretching sheet

2020 ◽  
Vol 9 (1) ◽  
pp. 233-243 ◽  
Author(s):  
Nainaru Tarakaramu ◽  
P.V. Satya Narayana ◽  
Bhumarapu Venkateswarlu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Stretching Sheet ◽  
Three Dimensional ◽  
Variable Thermal Conductivity ◽  
Normal Velocity ◽  
Transfer Coefficients ◽  
Similarity Transformations ◽  
Frictional Coefficients ◽  
The Impact

AbstractThe present investigation deals with the steady three-dimensional flow and heat transfer of nanofluids due to stretching sheet in the presence of magnetic field and heat source. Three types of water based nanoparticles namely, copper (Cu), aluminium oxide (Al2O3), and titanium dioxide (TiO2) are considered in this study. The temperature dependent variable thermal conductivity and thermal radiation has been introduced in the energy equation. Using suitable similarity transformations the dimensional non-linear expressions are converted into dimensionless system and are then solved numerically by Runge-Kutta-Fehlberg scheme along with well-known shooting technique. The impact of various flow parameters on axial and transverse velocities, temperature, surface frictional coefficients and rate of heat transfer coefficients are visualized both in qualitative and quantitative manners in the vicinity of stretching sheet. The results reviled that the temperature and velocity of the fluid rise with increasing values of variable thermal conductivity parameter. Also, the temperature and normal velocity of the fluid in case of Cu-water nanoparticles is more than that of Al2O3- water nanofluid. On the other hand, the axial velocity of the fluid in case of Al2O3- water nanofluid is more than that of TiO2nanoparticles. In addition, the current outcomes are matched with the previously published consequences and initiate to be a good contract as a limiting sense.

scholarly journals The Impact of Variable Thermal Conductivity of Insulation Materials on the Building Energy Performance in Hot Climate

2019 ◽  
Vol 103 ◽  
pp. 02001 ◽  
Author(s):  
Maatouk Khoukhi ◽  
Ahmed Hassan ◽  
Shaimaa Abdelbaqi
Keyword(s):  
Thermal Conductivity ◽  
Energy Performance ◽  
Variable Thermal Conductivity ◽  
Transfer Model ◽  
Ambient Conditions ◽  
K Value ◽  
Hot Climate ◽  
Building Wall ◽  
Wall Assembly ◽  
The Impact

This paper illustrates the impact of embedding an insulation layer of variable thermal conductivity in a typical building wall on the cooling effect and energy performance. The evaluation was performed by applying a conjugate heat transfer model, which was tested in extremely hot conditions of Al Ain (UAE). The thermal performance of a building incorporating insulation layers of variable thermal conductivity (k-value) was compared to a non-variable thermal conductivity system by quantifying the additional heat transferred due to the k-relationship with time. The results show that, when the k-value is a function of operating temperature, its effects on the temperature profile through the wall assembly during daytime is significant compared with that obtained when a constant k-value for the polystyrene (EPS) insulation is adopted. A similar trend in the evolution of temperatures during the day and across the wall section was observed when EPS material with different moisture content was evaluated. For the polyurethane insulation, the inner surface temperature reached 44 °C when constant k-value was adopted, increasing to 48.5 °C when the k-value was allowed to vary under the same ambient conditions.

scholarly journals Effects of Exothermic/Endothermic Chemical Reactions with Arrhenius Activation Energy on MHD Free Convection and Mass Transfer Flow in Presence of Thermal Radiation

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Kh. Abdul Maleque
Keyword(s):  
Activation Energy ◽  
Mass Transfer ◽  
Differential Equations ◽  
Thermal Radiation ◽  
Chemical Reactions ◽  
Numerical Solutions ◽  
Porous Plate ◽  
Local Similarity ◽  
Shooting Methods ◽  
Arrhenius Activation Energy

A local similarity solution of unsteady MHD natural convection heat and mass transfer boundary layer flow past a flat porous plate within the presence of thermal radiation is investigated. The effects of exothermic and endothermic chemical reactions with Arrhenius activation energy on the velocity, temperature, and concentration are also studied in this paper. The governing partial differential equations are reduced to ordinary differential equations by introducing locally similarity transformation (Maleque (2010)). Numerical solutions to the reduced nonlinear similarity equations are then obtained by adopting Runge-Kutta and shooting methods using the Nachtsheim-Swigert iteration technique. The results of the numerical solution are obtained for both steady and unsteady cases then presented graphically in the form of velocity, temperature, and concentration profiles. Comparison has been made for steady flow () and shows excellent agreement with Bestman (1990), hence encouragement for the use of the present computations.

Influence of Initial Stress and Variable Thermal Conductivity on a Fiber-Reinforced Magneto-Thermoelastic Solid with Micro-Temperatures by Multi-Phase-Lags Model

2021 ◽  
pp. 2250007
Author(s):  
Amnah M. Alharbi ◽  
Samia M. Said ◽  
Elsayed M. Abd-Elaziz ◽  
Mohamed I. A. Othman
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Initial Stress ◽  
Thermodynamic Temperature ◽  
Variable Thermal Conductivity ◽  
Fiber Reinforced ◽  
Phase Lags ◽  
Multi Phase ◽  
The Impact ◽  
Physical Quantities

This paper presents the theory of multi-phase-lags thermoelasticity that was used to study the wave propagation on a fiber-reinforced thermoelastic medium with micro-temperatures. The medium was considered to be homogeneous, isotropic and thermal conductivity as a linear function of thermodynamic temperature. The Fourier transform and Laplace transform are employed to solve the governing equations and obtained the solution of the physical quantities. The graphical illustrations of the impact that initial stress, variable thermal conductivity, magnetic field, and the phase-lags have on the field functions are presented. The variable thermal conductivity, initial stress, and magnetic field have a good impact in all the physical quantities.

scholarly journals Energy transport analysis in flow of Carreau nanofluid inspired by variable thermal conductivity and zero mass flux conditions

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199496
Author(s):  
Zahoor Iqbal ◽  
Masood Khan ◽  
Aamir Hamid ◽  
Awais Ahmed
Keyword(s):  
Thermal Conductivity ◽  
Activation Energy ◽  
Mass Flux ◽  
Numerical Technique ◽  
Variable Thermal Conductivity ◽  
Convection Flow ◽  
Physical Constraints ◽  
The Core ◽  
Zero Mass ◽  
Carreau Nanofluid

The presence of nanometric particles in the base fluids lead to form nanofluids. Nanofluids are prominent due to their astonishing features in thermally conducting flows and in the development of electronic and mechanical devices. Based on these motivations, we have designed our article to investigate the thermal conduction features in the free and forced convection flow of unsteady Carreau nanofluid due to stretching cylinder with the effects of variable magnetic field. Moreover, the transport of thermal energy in the flow is properly examined by including the impacts of variable thermal conductivity and nonuniform heat rise/fall. Furthermore, the transport of solutal energy in the flow of nanofluid is encountered under the influences of activation energy and binary chemical reactions. A momentous feature of this study is to employ the zero-mass flux condition at the wall of the cylinder. A section of this study is proposed for mathematical modelling of the current problem. Moreover, the impacts of involved physical constraints are explored by employing an efficient numerical technique namely bvp4c. The features of all physical constraints on flow, thermal and solutal curves are illustrated in the form of graphs and discussed with reasonable physical arguments in discussion section of the article. The core findings of this study are mentioned in the section of closing remarks. The core upshot of the current study is that the nanoparticles concentration rate of nanofluid depicts ascending trend for escalating values of activation energy constraint. A significant upsurge in the coefficients of skin friction and Nusselt number is detected with an escalation in the constraints of buoyancy and thermophoresis forces, respectively. The references regarding this article are also provided at the end.

scholarly journals Chemical reaction and thermal radiation impact on a nanofluid flow in a rotating channel with Hall current

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu-Pei Lv ◽  
Naila Shaheen ◽  
Muhammad Ramzan ◽  
M. Mursaleen ◽  
Kottakkaran Sooppy Nisar ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Activation Energy ◽  
Thermal Radiation ◽  
Chemical Reaction ◽  
Schmidt Number ◽  
Variable Thermal Conductivity ◽  
Nanofluid Flow ◽  
Source Sink ◽  
Chemical Reaction Parameter ◽  
Rotating Channel

AbstractThe objective of the present exploration is to examine the nanoliquid flow amid two horizontal infinite plates. The lower plate is stretchable and permeable. The uniqueness of the flow model is assimilated with the Hall effect, variable thermal conductivity, thermal radiation, and irregular heat source/sink. Transmission of mass is enhanced with the impression of chemical reaction incorporated with activation energy. Appropriate similarity transformation is applied to transform the formulated problem into ordinary differential equations (ODEs). The numerical solution is obtained by employing MATLAB software function bvp4c. The dimensionless parameters are graphically illustrated and discussed for the involved profiles. An increasing behavior is exhibited by the temperature field on escalating the Brownian motion, thermophoresis parameter, variable thermal conductivity, and radiation parameter. For larger values of Schmidt number and chemical reaction parameter, the concentration profile deteriorates, while a reverse trend is seen for activation energy. The rate of heat transfer is strengthened at the lower wall on amplifying the Prandtl number. A comparative analysis of the present investigation with already published work is also added to substantiate the envisioned problem.

Simultaneous impact of magnetic and Arrhenius activation energy on the flow of Casson hybrid nanofluid over a vertically moving plate

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Sarwe D. U. ◽  
Shanker B. ◽  
Mishra R. ◽  
Kumar R. S. V. ◽  
Shekar M. N. R.
Keyword(s):  
Activation Energy ◽  
Current Model ◽  
Energy Parameter ◽  
Hybrid Nanofluid ◽  
Arrhenius Activation Energy ◽  
Moving Plate ◽  
Convective Boundary ◽  
Simultaneous Impact ◽  
Sakiadis Flow ◽  
The Impact

The present study deals with the Blasius and Sakiadis flow of Casson hybrid nanoliquid over a vertically moving plate under the influence of magnetic effect and Joule heating. Here, we considered Silver and Copper as nanoparticles suspended in 50% Ethylene-Glycol (EG) as base fluid. Further, the Arrhenius activation energy and convective boundary conditions are taken into the account. The set of PDEs of the current model are converted into ODEs by using suitable similarity variables. The reduced ODEs are numerically solved with the help of RKF-45 method by adopting shooting scheme. The impact of various pertinent parameters on the fluid fields is deliberated graphically. The result outcomes reveal that, rise in values of Casson parameter diminishes the velocity gradient. The escalated values of magnetic parameter decline the velocity profile but reverse trend is detected in thermal and concentration profiles. Moreover, the augmentation in the activation energy parameter elevates the concentration profile.

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