scholarly journals The Investigation of MHD Williamson Nanofluid over Stretching Cylinder with the Effect of Activation Energy

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Wubshet Ibrahim ◽  
Mekonnen Negera
Keyword(s):  
Activation Energy ◽  
Mass Transfer ◽  
Nusselt Number ◽  
Skin Friction Coefficient ◽  
Stretching Cylinder ◽  
Concentration Increase ◽  
Dimensionless Velocity ◽  
Heat Generation Or Absorption ◽  
Published Paper ◽  
Good Agreement

In this paper, we discussed the effect of activation energy on mixed convective heat and mass transfer of Williamson nanofluid with heat generation or absorption over a stretching cylinder. Dimensionless ordinary differential equations are obtained from the modeled PDEs by using appropriate transformations. Numerical results of the skin friction coefficient, Nusselt number, and Sherwood number for different parameters are computed. The effects of the physical parameter on temperature, velocity, and concentration have been discussed in detail. From the result, it is found that the dimensionless velocity decreases whereas temperature and concentration increase when the porous parameter is enhanced. The present result has been compared with published paper and found good agreement.

Binary chemical reaction with activation energy in dissipative flow of non-Newtonian nanomaterial

2020 ◽  
Vol 19 (03) ◽  
pp. 2040006 ◽  
Author(s):  
M. Ijaz Khan ◽  
Faris Alzahrani
Keyword(s):  
Activation Energy ◽  
Mass Transfer ◽  
Chemical Reaction ◽  
Ohmic Heating ◽  
Skin Friction Coefficient ◽  
Entropy Rate ◽  
Brownian Diffusion ◽  
Jeffrey Fluid ◽  
Bejan Number ◽  
Engineering Sciences

This paper deals with the entropy optimization and heat transport of magneto-nanomaterial flow of non-Newtonian (Jeffrey fluid) towards a curved stretched surface. MHD fluid is accounted. The modeling of energy expression is developed subject to Brownian diffusion, Joule (Ohmic) heating, thermophoresis and viscous dissipation. Total entropy rate is discussed with the help of fluid friction irreversibility, mass transfer irreversibility, Joule heating irreversibility and heat transfer irreversibility. Binary chemical reaction with the smallest amount of activation energy is further considered. The governing equations of Jeffrey fluid with effects of hydrodynamic, thermal radiation, heat and mass transfer were solved through built-in-shooting method. The flow variables on the entropy rate, velocity field, concentration, Bejan number, skin friction coefficient and temperature are physically discussed through various graphs. The outcomes reveal that the entropy rate increases with an enhancement in curvature parameter. Such obtained outcomes help in mechanical and industrial engineering sciences. Moreover, the velocity and temperature decays versus ratio of relaxation to retardation times are also noticed.

Turbulent Boundary Layers With Mass Transfer by the Dorodnitsyn Finite Element Method

1987 ◽  
Vol 54 (1) ◽  
pp. 197-202 ◽  
Author(s):  
C. A. J. Fletcher ◽  
R. W. Fleet
Keyword(s):  
Mass Transfer ◽  
Finite Element ◽  
Boundary Layers ◽  
Adverse Pressure Gradient ◽  
Skin Friction Coefficient ◽  
Turbulent Boundary Layers ◽  
Element Formulation ◽  
Surface Mass ◽  
Surface Mass Transfer ◽  
Good Agreement

The Dorodnitsyn finite element formulation is extended to cover incompressible, two-dimensional turbulent boundary layers with surface mass transfer in the normal direction. The method is shown to give accurate and economical answers with only eleven points spanning the boundary layer. Good agreement is obtained when the computational solutions are compared with the experimental results of McQuaid [13] for skin friction coefficient, displacement and momentum thickness and velocity profiles. Zero and adverse pressure gradient and discontinuous injection cases have been considered.

Exploration of flow and heat transfer of non-Newtonian nanofluid over a stretching sheet by considering slip factor

2019 ◽  
Vol 30 (4) ◽  
pp. 1991-2001 ◽  
Author(s):  
K. Ganesh Kumar
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Nusselt Number ◽  
Brownian Motion ◽  
Friction Coefficient ◽  
Stretching Sheet ◽  
Skin Friction Coefficient ◽  
Content Type ◽  
Flow And Heat Transfer ◽  
Brownian Motion Parameter

Purpose Here, the present paper characteristics flow and heat transfer of non-Newtonian nanofluid over a stretching sheet. Energy expression is modeled subject to slip factor phenomenon. Consideration of chemical reaction characterizes the mass transfer mechanism. Design/methodology/approach The use of transformation variables reduces the PDEs into non-linear ODEs. The obtained nonlinear complex problems are computed numerically through RKF-45 technique. The effects of the different physical parameters on the temperature and concentration distribution are analyzed. Findings The nature of the reduced Nusselt number, reduced Sherwood number and skin friction coefficient also described as a function of different parameters arising in the problem. It is found that the rate of mass transfer enhances for enhancing values Brownian motion parameter and thermophoresis parameter. Originality/value The nature of the reduced Nusselt number, reduced Sherwood number and skin friction coefficient also described as a function of different parameters arising in the problem. It is found that, the rate of mass transfer enhances for enhancing values Brownian motion parameter and thermophoresis parameter.

Activation energy impact on radiated magneto-Sisko nanofluid flow over a stretching and slipping cylinder: entropy analysis

2020 ◽  
Vol 16 (5) ◽  
pp. 1085-1115
Author(s):  
S. Sarkar ◽  
R.N. Jana ◽  
S. Das
Keyword(s):  
Activation Energy ◽  
Mass Transfer ◽  
Brownian Motion ◽  
Boundary Conditions ◽  
Entropy Generation ◽  
Velocity Slip ◽  
Stretching Cylinder ◽  
Convective Boundary Conditions ◽  
Convective Boundary ◽  
Content Type

PurposeThe purpose of this article is to analyze the heat and mass transfer with entropy generation during magnetohydrodynamics (MHD) flow of non-Newtonian Sisko nanofluid over a linearly stretching cylinder under the influence of velocity slip, chemical reaction and thermal radiation. The Brownian motion, thermophoresis and activation energy are assimilated in this nanofluid model. Convective boundary conditions on heat and mass transfer are considered. The physical model may have diverse applications in several areas of technology underlying thermohydrodynamics including supercritical fluid extraction, refrigeration, ink-jet printing and so on.Design/methodology/approachThe dimensional governing equations are nondimensionalized by using appropriate similarity variables. The resulting boundary value problem is converted into initial value problem using the method of superposition and numerically computed by employing well-known fourth-order Runge–Kutta–Fehlberg approach along with shooting technique (RKF4SM). The quantitative impacts of emerging physical parameters on the velocity, temperature, concentration, skin friction coefficient, Nusselt number, Sherwood number, entropy generation rate and Bejan number are presented graphically and in tabular form, and the salient features are comprehensively discussed.FindingsFrom graphical outcomes, it is concluded that the slip parameters greatly influence the flow characteristics. Fluid temperature is elevated with rising radiation parameter and thermal Biot number. Nanoparticle concentration is reported in decreasing form with activation energy parameter. Entropy is found to be an increasing function of magnetic field, Brownian motion and material parameters. The entropy is less generated for shear-thinning fluid compared to shear-thickening as well as Newtonian fluids in the system.Originality/valueTill now no study has been documented to explore the impact of binary chemical reaction with Arrhenius activation energy on entropy generation in an MHD boundary layer flow of non-Newtonian Sisko nanofluid over a linear stretching cylinder with velocity slip and convective boundary conditions.

Numerical solution of MHD Sisko fluid over a stretching cylinder and heat transfer analysis

2016 ◽  
Vol 26 (6) ◽  
pp. 1787-1801 ◽  
Author(s):  
M.Y. Malik ◽  
Arif Hussain ◽  
T. Salahuddin ◽  
M. Awais
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Nusselt Number ◽  
Differential Equations ◽  
Skin Friction ◽  
Skin Friction Coefficient ◽  
Stretching Cylinder ◽  
Sisko Fluid ◽  
Content Type ◽  
Curvature Parameter

Purpose – The purpose of this paper is to examine the Sisko fluid model over a stretching cylinder with heat transfer and magnetohydrodynamics. Design/methodology/approach – The boundary layer approach is employed to simplify the governing equations. Suitable similarity transformations are used to transform the governing partial differential equations into ordinary differential equations. In order to solve this system of ordinary differential equations numerically, shooting method in conjunction with Runge-Kutta-Fehlberg method is used. Findings – The effects of physical parameters involved in velocity and temperature profiles are shown through graphs. It is observed that Sisko fluid parameter and curvature parameter enhances fluid velocity while motion of fluid is retarded by increasing magnetic field strength. Additionally temperature of fluid raise with curvature parameter while it fall down for larger values of Prandtl number. Skin friction coefficient and Nusselt number are computed and presented in graphs and tables for further analysis. It can be seen that curvature parameter increases both skin friction and Nusselt number while magnetic field and Prandtl number decayed skin friction and Nusselt number, respectively. Also Sisko parameter enlarges skin friction coefficient. The accuracy of solution is verified by comparing it with existing literature. Originality/value – The computed results are interested for industrial and engineering processes, especially in cooling of nuclear reactors.

scholarly journals Analyzing the impact of induced magnetic flux and Fourier’s and Fick’s theories on the Carreau-Yasuda nanofluid flow

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seemab Bashir ◽  
Muhammad Ramzan ◽  
Jae Dong Chung ◽  
Yu-Ming Chu ◽  
Seifedine Kadry
Keyword(s):  
Activation Energy ◽  
Nusselt Number ◽  
Brownian Motion ◽  
Friction Coefficient ◽  
Differential Equations ◽  
Skin Friction ◽  
Chemical Reaction ◽  
Skin Friction Coefficient ◽  
Nanofluid Flow ◽  
Stretching Ratio

AbstractThe current study analyzes the effects of modified Fourier and Fick's theories on the Carreau-Yasuda nanofluid flow over a stretched surface accompanying activation energy with binary chemical reaction. Mechanism of heat transfer is observed in the occurrence of heat source/sink and Newtonian heating. The induced magnetic field is incorporated to boost the electric conductivity of nanofluid. The formulation of the model consists of nonlinear coupled partial differential equations that are transmuted into coupled ordinary differential equations with high nonlinearity by applying boundary layer approximation. The numerical solution of this coupled system is carried out by implementing the MATLAB solver bvp4c package. Also, to verify the accuracy of the numerical scheme grid-free analysis for the Nusselt number is presented. The influence of different parameters, for example, reciprocal magnetic Prandtl number, stretching ratio parameter, Brownian motion, thermophoresis, and Schmidt number on the physical quantities like velocity, temperature distribution, and concentration distribution are addressed with graphs. The Skin friction coefficient and local Nusselt number for different parameters are estimated through Tables. The analysis shows that the concentration of nanoparticles increases on increasing the chemical reaction with activation energy and also Brownian motion efficiency and thermophoresis parameter increases the nanoparticle concentration. Opposite behavior of velocity profile and the Skin friction coefficient is observed for increasing the stretching ratio parameter. In order to validate the present results, a comparison with previously published results is presented. Also, Factors of thermal and solutal relaxation time effectively contribute to optimizing the process of stretchable surface chilling, which is important in many industrial applications.

Heat transfer from electrically heated cylinders

1964 ◽  
Vol 280 (1383) ◽  
pp. 486-527 ◽  
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Local Heat Transfer ◽  
Skin Friction Coefficient ◽  
Hot Wire ◽  
Resistance Thermometer ◽  
The Wire ◽  
Good Agreement

The heat transfer from small electrically heated cylinders has been studied with particular reference to the performance of hot-wire anemometers. The thermal equilibrium for a cylinder normal to the flow was investigated in detail and the convective transfer to the fluid, conductive flow to the supports and the radiation losses were measured. A simple model of the heat transfer at the surface showed that the Nusselt number was proportional to the product of the skin friction coefficient, C f , and the Reynolds and Prandtl numbers, and was in good agreement with the measurements. At the same time it was argued that the skin friction coefficient was independent of the temperature of the cylinder, provided that the fluid properties are evaluated for the conditions at the surface in the absence of heat transfer. This is in general agreement with published results and the measurements described here. The same model showed that the coefficient of local heat transfer was expressed by h w = C f ρ V c v k w /π k 0 , where k w is the conductivity of air at the temperature of the wire surface. This expression was also in good agreement with the measurements which showed that the temperature dependence of the heat transfer coefficient can be expressed as h w = h 0 (1 + β T ), if it is assumed that k w = k 0 (1 + β T ). The measurements also showed that h 0 was proportional to the product of the mass flux and the skin friction coefficient, C f . The chief source of experimental error in the measurement of Nusselt number was found to be in the estimation of the surface temperature of the wire, the reason being that the hot wire itself was used as a resistance thermometer for this purpose. This difficulty is a major factor in the large scatter among Nusselt number measurements by different observers.

Modeling of mass transfer in biofilms in oscillatory flow conditions using k-ɛ turbulence model

2003 ◽  
Vol 3 (1-2) ◽  
pp. 201-207
Author(s):  
H. Nagaoka ◽  
T. Nakano ◽  
D. Akimoto
Keyword(s):  
Numerical Simulation ◽  
Mass Transfer ◽  
Turbulence Model ◽  
Uptake Rate ◽  
Oscillatory Flow ◽  
Substrate Uptake ◽  
Flow Conditions ◽  
Mass Transfer Mechanism ◽  
Substrate Uptake Rate ◽  
Good Agreement

The objective of this research is to investigate mass transfer mechanism in biofilms under oscillatory flow conditions. Numerical simulation of turbulence near a biofilm was conducted using the low Reynold’s number k-ɛ turbulence model. Substrate transfer in biofilms under oscillatory flow conditions was assumed to be carried out by turbulent diffusion caused by fluid movement and substrate concentration profile in biofilm was calculated. An experiment was carried out to measure velocity profile near a biofilm under oscillatory flow conditions and the influence of the turbulence on substrate uptake rate by the biofilm was also measured. Measured turbulence was in good agreement with the calculated one and the influence of the turbulence on the substrate uptake rate was well explained by the simulation.

The effect of two-phase flow regime on hydrodynamics and mass transfer in a horizontal-tube gas-liquid reactor

1985 ◽  
Vol 50 (3) ◽  
pp. 745-757 ◽  
Author(s):  
Andreas Zahn ◽  
Lothar Ebner ◽  
Kurt Winkler ◽  
Jan Kratochvíl ◽  
Jindřich Zahradník
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Flow Regime ◽  
Liquid Flow ◽  
Horizontal Tube ◽  
Liquid Holdup ◽  
Two Phase ◽  
Flow Rates ◽  
Type Relation ◽  
Good Agreement

The effect of two-phase flow regime on decisive hydrodynamic and mass transfer characteristics of horizontal-tube gas-liquid reactors (pressure drop, liquid holdup, kLaL) was determined in a cocurrent-flow experimental unit of the length 4.15 m and diameter 0.05 m with air-water system. An adjustable-height weir was installed in the separation chamber at the reactor outlet to simulate the effect of internal baffles on reactor hydrodynamics. Flow regime maps were developed in the whole range of experimental gas and liquid flow rates both for the weirless arrangement and for the weir height 0.05 m, the former being in good agreement with flow-pattern boundaries presented by Mandhane. In the whole range of experi-mental conditions pressure drop data could be well correlated as a function of gas and liquid flow rates by an empirical exponential-type relation with specific sets of coefficients obtained for individual flow regimes from experimental data. Good agreement was observed between values of pressure drop obtained for weirless arrangement and data calculated from the Lockhart-Martinelli correlation while the contribution of weir to the overall pressure drop was well described by a relation proposed for the pressure loss in closed-end tubes. In the region of negligible weir influence values of liquid holdup were again succesfully correlated by the Lockhart-Martinelli relation while the dependence of liquid holdup data on gas and liquid flow rates obtained under conditions of significant weir effect (i.e. at low flow rates of both phases) could be well described by an empirical exponential-type relation. Results of preliminary kLaL measurements confirmed the decisive effect of the rate of energy dissipation on the intensity of interfacial mass transfer in gas-liquid dispersions.

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