scholarly journals Numerical analysis of heat and mass transfer along a stretching wedge surface

2017 ◽  
Vol 14 (2) ◽  
pp. 135-144
Author(s):  
M. Ali ◽  
M. A. Alim ◽  
R. Nasrin ◽  
M. S. Alam
Keyword(s):  
Brownian Motion ◽  
Differential Equations ◽  
Pressure Gradient ◽  
Ordinary Differential Equations ◽  
Velocity Ratio ◽  
Lewis Number ◽  
Nanoparticle Concentration ◽  
Wedge Surface ◽  
Mhd Boundary Layer ◽  
Moving Wedge

In this work, the effects of dimensionless parameters on the velocity field, thermal field and nanoparticle concentration have been analyzed. In this respect, the magnetohydrodynamic (MHD) boundary layer nanofluid flow along a moving wedge is considered. Therefore, a similarity solution has been derived like Falkner – Skan solution and identified the point of inflexion. So the governing partial differential equations transform into ordinary differential equations by using the similarity transformation. These ordinary differential equations are numerically solved using fourth order Runge–Kutta method along with shooting technique. The present results have been shown graphically and in tabular form. From the graph, the results indicate that the velocity increases with increasing values of pressure gradient, magnetic induction and velocity ratio. The temperature decreases for velocity ratio, Brownian motion and Prandtl number but opposite result arises for increasing values of thermophoresis. The nanoparticle concentration decreases with an increase in pressure gradient, Brownian motion and Lewis number, but increases for thermophoresis. Besides, the solution of nanoparticle concentration exists in the case of Brownian motion is less than 0.2, thermophoresis is less than 0.14 and lewis number is greater than 1.0. Finally, for validity and accuracy the present results have been compared with previous work and found to be in good agreement. 

scholarly journals Boundary Layer Analysis in Nanofluid Flow Past a Permeable Moving Wedge in Presence of Magnetic Field by Using Falkner – Skan Model

2018 ◽  
Vol 23 (4) ◽  
pp. 1005-1013 ◽  
Author(s):  
M. Ali ◽  
M.A. Alim
Keyword(s):  
Boundary Layer ◽  
Brownian Motion ◽  
Differential Equations ◽  
Pressure Gradient ◽  
Ordinary Differential Equations ◽  
Velocity Ratio ◽  
Lewis Number ◽  
Motion Parameter ◽  
Gradient Parameter ◽  
Brownian Motion Parameter

Abstract In the present work, the effect of various dimensionless parameters on the momentum, thermal and concentration boundary layer are analyzed. In this respect we have considered the MHD boundary layer flow of heat and transfer over a porous wedge surface in a nanofluid. The governing partial differential equations are converted into ordinary differential equations by using the similarity transformation. These ordinary differential equations are numerically solved using fourth order Runge–Kutta method along with shooting technique. The present results have been shown in a graphical and also in tabular form. The results indicate that the momentum boundary layer thickness reduces with increasing values of the pressure gradient parameter β for different situations and also for the magnetic parameter M but increases for the velocity ratio parameter λ and permeability parameter K*. The heat transfer rate increases for the pressure gradient parameter β, velocity ratio parameter λ, Brownian motion parameter Nb and Prandtl number Pr but opposite result is found for the increasing values of the thermoporesis parameter Nt. The nanoparticle concentration rate increases with an increase in the pressure gradient parameter β, velocity ratio parameter λ, Brownian motion parameter Nb and Lewis number Le, but decreases for the thermoporesis parameter Nt. Finally, the numerical results has compared with previously published studies and found to be in good agreement. So the validity of our results is ensured.

Computational analysis of non-Newtonian boundary layer flow of nanofluid past a semi-infinite vertical plate with partial slip

2018 ◽  
Vol 7 (1) ◽  
pp. 29-43 ◽  
Author(s):  
C.H. Amanulla ◽  
N. Nagendra ◽  
M. Suryanarayana Reddy
Keyword(s):  
Brownian Motion ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Vertical Plate ◽  
Lewis Number ◽  
Velocity Slip ◽  
Partial Slip ◽  
Thermal Slip ◽  
Slip Factor ◽  
Infinite Vertical Plate

Abstract An analysis of this paper is examined, two-dimensional, laminar with heat and mass transfer of natural convective nanofluid flow past a semi-infinite vertical plate surface with velocity and thermal slip effects are studied theoretically. The coupled governing partial differential equations are transformed to ordinary differential equations by using non-similarity transformations. The obtained ordinary differential equations are solved numerically by a well-known method named as Keller Box Method (KBM). The influences of the emerging parameters i.e. Casson fluid parameter (β), Brownian motion parameter (Nb), thermophoresis parameter (Nt), Buoyancy ratio parameter (N), Lewis number (Le), Prandtl number (Pr), Velocity slip factor (Sf) and Thermal slip factor (ST) on velocity, temperature and nano-particle concentration distributions is illustrated graphically and interpreted at length. The major sources of nanoparticle migration in Nanofluids are Thermophoresis and Brownian motion. A suitable agreement with existing published literature is made and an excellent agreement is observed for the limiting case and also validation of solutions with a Nakamura tridiagonal method has been included. It is observed that nanoparticle concentrations on surface decreases with an increase in slip parameter. The study is relevant to enrobing processes for electric-conductive nano-materials, of potential use in aerospace and other industries.

scholarly journals Sensitivity Analysis on Thermal Conductivity Characteristics of a Water-Based Bionanofluid Flow Past a Wedge Surface

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Sze Qi Chan ◽  
Fazlina Aman ◽  
Syahira Mansur
Keyword(s):  
Brownian Motion ◽  
Differential Equations ◽  
Lewis Number ◽  
Motion Parameter ◽  
Nonlinear Ordinary Differential Equations ◽  
Shooting Technique ◽  
Wedge Surface ◽  
Water Based ◽  
Local Sherwood Number ◽  
Brownian Motion Parameter

Thermobioconvection boundary layer flow in a suspension of water-based bionanofluid holding both nanoparticles and motile microorganisms past a wedge surface was studied. The governing nonlinear partial differential equations on reference of the Buongiorno model were transformed into a set of coupled nonlinear ordinary differential equations. Shooting technique was then used to solve the transformed nonlinear ordinary differential equations numerically. The solutions were found to be contingent on several values of the governing parameters. As highlighted, the velocity profile as well as the skin friction coefficient was affected by the pressure gradient parameter, the function of the wedge angle parameter. On the other hand, the temperature, nanoparticle concentration, and density of motile microorganism’s distributions together with its corresponding local Nusselt number, local Sherwood number, and local density of the motile microorganisms change with the thermophoresis and Brownian motion parameter and so Lewis number, Schmidt number, and bioconvection Péclet number. An experimental scheme together with sensitivity analysis on the basis of Response Surface Methodology (RSM) was applied to examine the dependency of the response parameters of interest to the input parameters’ change. Obviously, local Nusselt number was more sensitive towards the Brownian motion parameter when the Brownian motion parameter was at 0.2 and 0.3. However local Sherwood number was more sensitive towards the Lewis number for all values of Brownian motion parameter. Compatibility found by comparing results between RSM and shooting technique gave confidence for the model’s accuracy. The findings would provide initial guidelines for future device fabrication. Finally, the numerical results obtained were thoroughly inspected and verified with the existing values reported by some researchers.

Pathwise convergent higher order numerical schemes for random ordinary differential equations

2007 ◽  
Vol 463 (2087) ◽  
pp. 2929-2944 ◽  
Author(s):  
Peter E Kloeden ◽  
Arnulf Jentzen
Keyword(s):  
Stochastic Process ◽  
Brownian Motion ◽  
Vector Field ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Higher Order ◽  
Time Variable ◽  
Numerical Schemes ◽  
Hölder Continuous ◽  
Usual Order

Random ordinary differential equations (RODEs) are ordinary differential equations (ODEs) with a stochastic process in their vector field. They can be analysed pathwise using deterministic calculus, but since the driving stochastic process is usually only Hölder continuous in time, the vector field is not differentiable in the time variable, so traditional numerical schemes for ODEs do not achieve their usual order of convergence when applied to RODEs. Nevertheless deterministic calculus can still be used to derive higher order numerical schemes for RODEs via integral versions of implicit Taylor-like expansions. The theory is developed systematically here and applied to illustrative examples involving Brownian motion and fractional Brownian motion as the driving processes.

scholarly journals Mathematical analysis of non-Newtonian nanofluid transport phenomena past a truncated cone with Newtonian heating

2018 ◽  
Vol 15 (1) ◽  
pp. 17-35 ◽  
Author(s):  
Nagendra Nallagundla ◽  
C. H. Amanulla ◽  
M. Suryanarayana Reddy
Keyword(s):  
Brownian Motion ◽  
Partial Differential Equations ◽  
Differential Equations ◽  
Biot Number ◽  
Lewis Number ◽  
Casson Fluid ◽  
External Boundary ◽  
Partial Differential ◽  
Truncated Cone ◽  
Highly Nonlinear

In the present study, we analyze the heat, momentum and mass (species) transfer in external boundary layer flow of Casson nanofluid past a truncated cone surface with Biot Number effect is studied theoretically. The effects of Brownian motion and thermophoresis are incorporated in the model in the presence of both heat and nanoparticle mass transfer Biot Number effect. The governing partial differential equations (PDEs) are transformed into highly nonlinear, coupled, multi-degree non-similar partial differential equations consisting of the momentum, energy and concentration equations via. Appropriate non-similarity transformations. These transformed conservation equations are solved subject to appropriate boundary conditions with a second order accurate finite difference method of the implicit type. The influences of the emerging parameters i.e. Casson fluid parameter (?), Brownian motion parameter (Nb) and thermophoresis parameter (Nt), Lewis number (Le), Buoyancy ratio parameter (N ), Prandtl number (Pr) and Biot number (Bi) on velocity, temperature and nano-particle concentration distributions is illustrated graphically and interpreted at length.  Validation of solutions with a Nakamura tri-diagonal method has been included. The study is relevant to enrobing processes for electric-conductive nano-materials of potential use in aerospace and other industries.

scholarly journals Magnetohydrodynamic (MHD) Boundary Layer Flow Past a Wedge with Heat Transfer and Viscous Effects of Nanofluid Embedded in Porous Media

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Wubshet Ibrahim ◽  
Ayele Tulu
Keyword(s):  
Boundary Layer ◽  
Porous Media ◽  
Brownian Motion ◽  
Prandtl Number ◽  
Boundary Layer Flow ◽  
Boundary Layer Thickness ◽  
Lewis Number ◽  
Mhd Boundary Layer ◽  
Layer Flow ◽  
Mhd Boundary Layer Flow

The problem of two-dimensional steady laminar MHD boundary layer flow past a wedge with heat and mass transfer of nanofluid embedded in porous media with viscous dissipation, Brownian motion, and thermophoresis effect is considered. Using suitable similarity transformations, the governing partial differential equations have been transformed to nonlinear higher-order ordinary differential equations. The transmuted model is shown to be controlled by a number of thermophysical parameters, viz. the pressure gradient, magnetic, permeability, Prandtl number, Lewis number, Brownian motion, thermophoresis, and Eckert number. The problem is then solved numerically using spectral quasilinearization method (SQLM). The accuracy of the method is checked against the previously published results and an excellent agreement has been obtained. The velocity boundary layer thickness reduces with an increase in pressure gradient, permeability, and magnetic parameters, whereas thermal boundary layer thickness increases with an increase in Eckert number, Brownian motion, and thermophoresis parameters. Greater values of Prandtl number, Lewis number, Brownian motion, and magnetic parameter reduce the nanoparticles concentration boundary layer.

Exact Analytical Solution for the Peristaltic Flow of Nanofluids in an Asymmetric Channel with Slip Effect of the Velocity, Temperature and Concentration

2014 ◽  
Vol 30 (4) ◽  
pp. 411-422 ◽  
Author(s):  
E. H. Aly ◽  
A. Ebaid
Keyword(s):  
Brownian Motion ◽  
Temperature Distribution ◽  
Pressure Gradient ◽  
Exact Solutions ◽  
Homotopy Perturbation Method ◽  
Pressure Rise ◽  
Peristaltic Flow ◽  
Rise Velocity ◽  
Nanoparticle Concentration ◽  
Homotopy Perturbation

AbstractThe peristaltic flow of nanofluids under the effect of slip conditions was theoretically investigated. The mathematical model was governed by a system of linear and non-linear partial differential equations with prescribed boundary conditions. Then, the exact solutions were successfully obtained and reported for the first time in the present work. These exact solutions were then used for studying the effects of the slip, thermophoresis, Brownian motion parameters and many others on the pressure rise, velocity profiles, temperature distribution, nanoparticle concentration and pressure gradient. In addition, it is proved that the obtained exact solutions are reduced to the literature results in the special cases.In the general case, it was found that on comparing the current solutions with the approximate ones obtained using the homotopy perturbation method in literature, remarkable differences have been detected for behaviour of the pressure rise, velocity profiles, temperature distribution, nanoparticle concentration and finally the pressure gradient. An example of these differences is about effect of the Brownian motion parameter on the velocity profile; where it was shown in this paper that the small values of this parameter have not a significant effect on the velocity, while this situation was completely different in the published work. Many other significant differences have been also discussed. Therefore, these observed differences recommend the necessity of including the convergence issue when applying the homotopy perturbation method or any other series solution method to solve a physical model. In conclusion. The current results may be considered as a base for any future analysis and/or comparisons.

Full-size mathematical model of the fuel metering unit

2011 ◽  
Vol 8 (1) ◽  
pp. 249-256
Author(s):  
E.Sh. Nasibullaeva ◽  
E.V. Denisova ◽  
I.Sh. Nasibullayev
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Pressure Gradient ◽  
Ordinary Differential Equations ◽  
Constant Pressure ◽  
Initial Conditions ◽  
Control Valve ◽  
Nonlinear Mathematical Model ◽  
Full Size

The paper presents a nonlinear mathematical model for the operation of the fuel metering unit, which takes into account the operation of the control valve, which includes two pistons and three fuel circuits. A technique for determining the initial conditions for a system of ordinary differential equations describing the movements of a servo piston, a piston of a constant pressure gradient valve and a piston of a control valve is proposed.

scholarly journals Numerical Analysis of Boundary Layer Flow Adjacent to a Thin Needle in Nanofluid with the Presence of Heat Source and Chemical Reaction

Symmetry ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 543 ◽  
Author(s):  
Siti Nur Alwani Salleh ◽  
Norfifah Bachok ◽  
Norihan Md Arifin ◽  
Fadzilah Md Ali
Keyword(s):  
Boundary Layer ◽  
Brownian Motion ◽  
Differential Equations ◽  
Chemical Reaction ◽  
Heat Generation ◽  
Boundary Layer Flow ◽  
Velocity Ratio ◽  
Dual Solutions ◽  
Reaction Parameters ◽  
Layer Flow

The steady boundary layer flow of a nanofluid past a thin needle under the influences of heat generation and chemical reaction is analyzed in the present work. The mathematical model has been formulated by using Buongiornos’s nanofluid model which incorporates the effect of the Brownian motion and thermophoretic diffusion. The governing coupled partial differential equations are transformed into a set of nonlinear ordinary differential equations by using appropriate similarity transformations. These equations are then computed numerically through MATLAB software using the implemented package called bvp4c. The influences of various parameters such as Brownian motion, thermophoresis, velocity ratio, needle thickness, heat generation and chemical reaction parameters on the flow, heat and mass characteristics are investigated. The physical characteristics which include the skin friction, heat and mass transfers, velocity, temperature and concentration are further elaborated with the variation of governing parameters and presented through graphs. It is observed that the multiple (dual) solutions are likely to exist when the needle moves against the direction of the fluid flow. It is also noticed that the reduction in needle thickness contributes to the enlargement of the region of the dual solutions. The determination of the stable solution has been done using a stability analysis. The results indicate that the upper branch solutions are linearly stable, while the lower branch solutions are linearly unstable. The study also revealed that the rate of heat transfer is a decreasing function of heat generation parameter, while the rate of mass transfer is an increasing function of heat generation and chemical reaction parameters.

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