Thermal analysis of higher-order chemical reactive viscoelastic nanofluids flow in porous media via stretching surface

Author(s):  
Mohamed R Eid ◽  
F Mabood

The essence of the present investigation is to reveal the hydrothermal variations of viscoelastic nanofluid flow in a porous medium over a stretchable surface. A higher-order chemical reaction is incorporated with thermophoresis and Brownian motion. Similarity conversions reduce the resulting equations into their dimensionless form and then solved using Runge-Kutta-Fehlberg (RKF) based shooting procedure. The effects of underlying factors on the flow are discussed through various graphs and tables. Computational results for noteworthy skin friction and heat and mass transport are presented and reviewed with sensible judgment. The study reveals that the fluid velocity reduces with incremental values of the viscoelastic parameter [Formula: see text] and magnetic strength. The temperature reduces for the suction parameter with the existence of stretchable but enhances with thermophoresis and Brownian motion effects. Heat transfer rate amplifies for [Formula: see text] but declines for [Formula: see text]. Mass transfer rate increases with the increase in Brownian parameter and Schmidt number. A comparative analysis shows a better agreement with previous results in limiting scenarios.

Author(s):  
Amina Manel Bouaziz ◽  
M.N. Bouaziz ◽  
A. Aziz

Free convective of nanofluid inside dispersive porous medium adjacent to a vertical plate under the effects of the zero mass nanoparticles flux condition and the thermal and solutal dispersions is studied. Buongiorno's model revised is used considering Darcy and non Darcy laminar flows, and isothermal or convective flux outer the wall. Dimensionless governing equations formulated using velocity, temperature, concentration and nanoparticle volume fraction have been solved by finite difference method that implements the 3-stage Lobatto collocation formula. The numerical data obtained with semi or full dispersions cases are compared to predictions made using the non dispersive porous medium. Taking into account the dispersions, the influence of the zero mass nanoparticles flux condition is examined to test the validity of the control active nanoparticle assumption. It is found mainly that the thermal transfers can reach more than 100% in connection with the case where of a semi-dispersion of the porous medium is applied. Realistic condition, i.e. zero mass flux should be addressed for the heat transfer rate rather than the mass transfer rate, discovered markedly different to the active condition. This signifies the importance of considering the zero nanoparticles mass flux and dispersions in the performance characterization of nanofluid flow in porous media.


2021 ◽  
Vol 3 (3) ◽  
Author(s):  
K. S. Srinivasa Babu ◽  
A. Parandhama ◽  
R. Bhuvana Vijaya

AbstractNumerical approach for a non-linear mixed convective magnetohydrodynamic two-dimensional Carreau nanofluid through an exponentially permeable stretching surface with viscous dissipation and velocity slip under the influence of Arrhenius activation energy in chemical reaction is reported. The effects of thermophoresis and Brownian motion are considered. The governing nonlinear equations of this model are transmuted into ODE’s through similarity variables and solved them with a shooting method based on R-K 4th order. Responses of fluid velocity, transfer rates (heat and mass) versus pertinent parameters of the problem for suitable values are obtained and the computational calculations for friction coefficient, Nusselt number and Sherwood number for the both suction and injections regions are presented in plots and tables. It is found that fluid velocity is an increasing function of Weissenberg number. Momentum boundary layer thickness is depressed by magnetic field impact. Increasing trend in Carreau fluid temperature is noticed due to larger values of thermophoresis and Brownian motion effects. Concentration field is a decreasing function of Brownian motion but an increasing function of thermophoresis. Activation energy augments the concentration curves and lowered by Schmidt number. Comparison of the results is made with already published results and we got good agreement.


Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1215
Author(s):  
Nur Azlina Mat Noor ◽  
Sharidan Shafie ◽  
Mohd Ariff Admon

The heat and mass transfer characteristics on hydromagnetic squeeze flow of Jeffrey nanofluid between two plates over a permeable medium by slip condition with the influences of viscous dissipation and chemical reaction is examined. Buongiorno’s nanofluid model, which includes Brownian motion and thermophoresis impacts, is implemented in this research. The governing nonlinear partial differential equations are transformed to the nonlinear ordinary differential equations via asimilarity transformation. The transformed equations are solved by employing numerical techniques of Keller-box. A comparison of the skin friction coefficient, Nusselt and Sherwood numbers with reported outputs in the journals are carried out to validate the present outputs. An excellent agreement is found. The results show that the squeezing of plates accelerates the velocity and wall shear stress. Furthermore, the velocity, temperature and concentration profile decrease when the Hartmann number and ratio of relaxation and retardation times increases. The raise in thermophoresis and viscous dissipation elevate the temperature profile and the heat transfer rate. Furthermore, the mass transfer rate declines due to the strong Brownian motion in the nanofluid, whereas it increases with the addition of chemical reaction and thermophoresis.


Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 540
Author(s):  
Shuang-Shuang Zhou ◽  
Muhammad Bilal ◽  
Muhammad Altaf Khan ◽  
Taseer Muhammad

The fluid flow over a rotating disk is critically important due to its application in a broad spectrum of industries and engineering and scientific fields. In this article, the traditional swirling flow of Von Karman is optimized for Maxwell fluid over a porous spinning disc with a consistent suction/injection effect. Buongiorno’s model, which incorporates the effect of both thermophoresis and Brownian motion, describes the Maxwell nanofluid nature. The dimensionless system of ordinary differential equations (ODEs) has been diminished from the system of modeled equations through a proper transformation framework. Which is numerically computed with the bvp4c method and for validity purposes, the results are compared with the RK4 technique. The effect of mathematical abstractions on velocity, energy, concentration, and magnetic power is sketched and debated. It is perceived that the mass transmission significantly rises with the thermophoresis parameter, while the velocities in angular and radial directions are reducing with enlarging of the viscosity parameter. Further, the influences of thermal radiation Rd and Brownian motion parameters are particularly more valuable to enhance fluid temperature. The fluid velocity is reduced by the action of suction effects. The suction effect grips the fluid particles towards the pores of the disk, which causes the momentum boundary layer reduction.


2021 ◽  
Vol 26 (2) ◽  
pp. 31-46
Author(s):  
Basant K. Jha ◽  
Ali J. Chitumu ◽  
Michael O. Oni

Abstract An analysis into the transient natural convective flow of a nanofluid in a vertical tube is made. The governing equations of momentum, heat transfer and nanoparticle volume fraction are deduced, and the influence of the thermophoresis parameter and Brownian motion is incorporated. By direct integration and variation of the parameter, analytical solutions are obtained for flow formation and heat/mass transfer at steady-state. On the other hand, due to the complexity of same problem at transient state, a numerical solution is used to solve the discretized equations of motion using the implicit finite difference technique. The influence of the thermophoresis parameter and Brownian motion is noted and well discussed. For accuracy check, a numerical comparison is made between the steady state and transient state solution at large time; this comparison gives an excellent agreement. The role of various principal parameters on velocity profile, temperature, concentration of nanoparticles, Sherwood and Nusselt numbers are presented graphically and well discussed. It is noted that the buoyancy ratio decreases the fluid velocity significantly.


2003 ◽  
Vol 68 (11) ◽  
pp. 2080-2092 ◽  
Author(s):  
Martin Keppert ◽  
Josef Krýsa ◽  
Anthony A. Wragg

The limiting diffusion current technique was used for investigation of free convective mass transfer at down-pointing up-facing isosceles triangular surfaces of varying length and inclination. As the mass transfer process, copper deposition from acidified copper(II) sulfate solution was used. It was found that the mass transfer rate increases with inclination from the vertical to the horizontal position and decreases with length of inclined surface. Correlation equations for 7 angles from 0 to 90° were found. The exponent in the ShL-RaL correlation ranged from 0.247 for the vertical case, indicating laminar flow, to 0.32 for inclinations of 60 to 90°, indicating mixed or turbulent flow. The general correlation ShL = 0.358(RaL sin θ)0.30 for the RaL sin θ range from 7 × 106 to 2 × 1011 and inclination range from 15 to 90° was obtained.


Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 74-88 ◽  
Author(s):  
Tanveer Sajid ◽  
Muhammad Sagheer ◽  
Shafqat Hussain ◽  
Faisal Shahzad

AbstractThe double-diffusive tangent hyperbolic nanofluid containing motile gyrotactic microorganisms and magnetohydrodynamics past a stretching sheet is examined. By adopting the scaling group of transformation, the governing equations of motion are transformed into a system of nonlinear ordinary differential equations. The Keller box scheme, a finite difference method, has been employed for the solution of the nonlinear ordinary differential equations. The behaviour of the working fluid against various parameters of physical nature has been analyzed through graphs and tables. The behaviour of different physical quantities of interest such as heat transfer rate, density of the motile gyrotactic microorganisms and mass transfer rate is also discussed in the form of tables and graphs. It is found that the modified Dufour parameter has an increasing effect on the temperature profile. The solute profile is observed to decay as a result of an augmentation in the nanofluid Lewis number.


Author(s):  
Venkatesh Puneeth ◽  
Sarpabhushana Manjunatha ◽  
Bijjanal Jayanna Gireesha ◽  
Rama Subba Reddy Gorla

The induced magnetic field for three-dimensional bio-convective flow of Casson nanofluid containing gyrotactic microorganisms along a vertical stretching sheet is investigated. The movement of these microorganisms cause bioconvection and they act as bio-active mixers that help in stabilising the nanoparticles in the suspension. The two forces, Thermophoresis and Brownian motion are incorporated in the Mathematical model along with Stefan blowing. The resulting model is transformed to ordinary differential equations using similarity transformations and are solved using [Formula: see text] method. The Velocity, Induced Magnetic field, Temperature, Concentration of Nanoparticles, and Motile density profiles are interpreted graphically. It is observed that the Casson parameter decreases the flow velocity and enhances the temperature, concentration, and motile density profiles and also it is noticed that the blowing enhances the nanofluid profiles whereas, suction diminishes the nanofluid profiles. On the other hand, it is perceived that the rate of heat conduction is enhanced with Thermophoresis and Brownian motion.


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