Influence Of Reactions Research Articles

Influence of Chemical Reaction on Marangoni Convective Flow of Nanoliquid in the Presence of Lorentz Forces and Thermal Radiation: A Numerical Investigation

Influence of Chemical Reaction on Marangoni Convective Flow of Nanoliquid in the Presence of Lorentz Forces and Thermal Radiation: A Numerical Investigation

Influence of Chemical Reaction and Nonlinear Thermal Radiation on Bioconvection of Nanofluid Containing Gyrotactic Microorganisms with Magnetic Field

This paper deals with the study of bioconvection in nanofluid containing motile gyrotactic microorganisms over an exponentially stretching sheet by considering nonlinear thermal radiation and transverse magnetic field. The governing nonlinear partial differential equations are first transformed into a set of nonlinear ordinary differential equations along with appropriate boundary conditions by using appropriate similarity transformations. Then, these equations are solved numerically by fifth-order Runge-Kutta-Fehlberg integration scheme with shooting technique. The influence of various important physical parameters and bioconvection parameter on velocity, temperature, concentration of nanoparticle, rescaled density of gyrotactic microorganism, local skin friction, Nusselt number, Sherwood number, etc. are studied graphically. It is found that an increase on the bioconvection Lewis number, bioconvection Peclet number, and concentration difference of motile microorganism parameter give rise to the density of motile microorganism. Also, nanoparticle concentration increases by increasing the chemical reaction parameter whereas it decreases by increasing the nonlinear thermal radiation parameter.

Non-Linear Convection in Chemically Reacting Fluid with an Induced Magnetic Field across a Vertical Porous Plate in the Presence of Heat Source/Sink

An investigation is carried out to observe the impacts of non-linear convection and induced magnetic field in the flow of viscous fluid over a porous plate under the influence of chemical reaction and heat source/sink. The plate is subjected to a regular free stream velocity as well as a suction velocity. The subjected non-linear problem is non-dimensionalized and analytic solutions are presented via perturbation method. The graphs are plotted to analyze the effect of relevant parameters on velocity, induced magnetic field, heat and mass transfer fields as well as friction factor, current density, Nusselt and Sherwood numbers. It is established that nonlinear convection aspect is destructive for thermal field and its layer thickness. The magnetic field effect enhances the thermal field while it reduces the velocity field. Also, the nonlinear effect subsides heat transfer rate significantly.

Radiated chemical reaction impacts on natural convective MHD mass transfer flow induced by a vertical cone

Abstract The consequence of thermal radiation in laminar natural convective hydromagnetic flow of viscous incompressible fluid past a vertical cone with mass transfer under the influence of chemical reaction with heat source/sink is presented here. The surface of the cone is focused to a variable wall temperature (VWT) and wall concentration (VWC). The fluid considered here is a gray absorbing and emitting, but non-scattering medium. The boundary layer dimensionless equations governing the flow are solved by an implicit finite-difference scheme of Crank–Nicolson which has speedy convergence and stable. This method converts the dimensionless equations into a system of tri-diagonal equations and which are then solved by using well known Thomas algorithm. Numerical solutions are obtained for momentum, temperature, concentration, local and average shear stress, heat and mass transfer rates for various values of parameters Pr, Sc, λ, Δ, Rd are established with graphical representations. We observed that the liquid velocity decreased for higher values of Prandtl and Schmidt numbers. The temperature is boost up for decreasing values of Schimdt and Prandtl numbers. The enhancement in radiative parameter gives more heat to liquid due to which temperature is enhanced significantly.

Magneto-hydrodynamics heat and mass transfer analysis of single and multi-wall carbon nanotubes over vertical cone with convective boundary condition

This paper investigate the numerical study of MHD boundary layer flow, heat and mass transfer analysis of water based nanofluids containing single and multi-walled CNTs over a vertical cone embedded in porous medium with convective boundary condition under the influence of chemical reaction and suction/injection. The similarity transformation technique is used for converting the governing non-linear partial differential equations, which represents the momentum, temperature and concentration of nanofluid, into the system of coupled ordinary differential equations. The transformed conservation equations together with boundary conditions are solved by using Finite element method. The sway of various pertinent parameters on hydrodynamic, thermal and solutal boundary layers is investigated and the results are displayed graphically. Furthermore, the values of local skin-friction coefficient, rate of temperature and concentration is also inspected for various values of non-dimensional parameters and the results are shown in tabular form. The numerical data results are compared with available data for special cases and found in good agreement. It is found that the skin-friction coefficient, Nusselt number and Sherwood number enhances with rising values of Biot number (B1) in both SWCNTs-water and MWCNTs-water based nanofluids.

English

English

Hydrogen production by biomass gasification in a supercritical water fluidized bed reactor: A CFD-DEM study

In this study, we used CFD-DEM model to simulate glucose gasification in a supercritical water fluidized bed reactor (SCWFBR). Simplified reaction kinetic model, including glucose decomposition, water gas shift reaction and methanation reaction, was used. Particle distributions, gas composition and reaction rate profiles were analyzed. Moreover, the influence of chemical reaction on flow behavior, and the effects of operation parameters, such as wall temperature, flow rates and initial bed height were investigated. The results show that high wall temperature, low flow rate and high initial bed height are in favor of gasification. However, lower H2 yield, gasification efficiency (GE) are found at flow rate below the minimum fluidization velocity. The simulation results show good agreement with the experimental results, demonstrating the validity of this model. The information obtained by the numerical study is useful for the operation and optimization of the gasification reactor.

Endoscopic effect in MHD peristaltic activity of hyperbolic tangent nanofluid: A numerical study

Influence of applied magnetic field in peristalsis of hyperbolic tangent nanofluid is investigated. Inner and outer tubes are inclined. These tubes satisfy wall properties effects. Inner tube in system is rigid while a travelling wave along outer tube generates the flow. Nanofluid is comprised of Brownian motion and thermophoretic effect. Energy equation is modeled in the presence of viscous dissipation and thermal radiation. Influence of chemical reaction is also taken into account. Formulation is completed when no-slip conditions for velocity, temperature and concentration hold. The resulting nonlinear system is solved numerically. Impacts of thermal radiation and Brownian motion on temperature are quite reverse.

Chemical reaction, thermal relaxation time and internal material parameter effects on MHD viscoelastic fluid with internal structure using the Cattaneo-Christov heat flux equation

In this article, the influence of thermal relaxation time and chemical reaction is studied on the MHD upper-convected viscoelastic fluid with internal structure using the Cattaneo-Christov heat flux equation for the first time in the literature. The flow-governing equations are formulated and are converted into their respective ordinary differential equations (ODEs) with the application of similarity functions. The resulting system of coupled nonlinear ODEs is solved along with the prescribed conditions at boundary using a finite-difference code in MATLAB. Influence of chemical reaction, thermal relaxation time and internal material parameter on the macroscopic and micropolar velocities as well as on the temperature and concentration profiles is examined along with other physical parameters (e.g., magnetic parameter, Eckert number, Prandtl number and fluid relaxation time). The accuracy of the obtained numerical solution is shown by comparing the physical parameters of interest with particular cases of existing results in the literature.

Influence of chemical reaction and heat source on dissipative MHD mixed convection flow of a Casson nanofluid over a nonlinear permeable stretching sheet

A mathematical model has been developed to study the mixed convection on MHD flow of Casson fluid over a nonlinearly permeable stretching sheet with thermal radiation, viscous dissipation, heat source/sink, chemical reaction and suction. In this investigation we also incorporated the Buogiorno’s type Nanofluid model that include the effect of Brownian motion and thermophoresis. Suitable similarity transformations are used to reduce the governing partial differential equations (PDEs) into a set of nonlinear ordinary differential equations (ODEs). These equations are solved using homotopy analysis method (HAM). The convergence of series solutions is discussed explicitly. A comparison has been made and found to be in good agreement with a previous published result on special cases of the problem. The graphical and tabulated results are given to deliberate the physical nature of the problem. Casson parameter is helpful for minimizing the skin friction, the rate of heat and mass transfer. Whereas suction is useful in improving the heat and mass transfer rates.

Influence of Chemical Reaction on Heat and Mass Transfer Flow of a Micropolar Fluid over a Permeable Channel with Radiation and Heat Generation

The effects of chemical reaction on heat and mass transfer flow of a micropolar fluid in a permeable channel with heat generation and thermal radiation is studied. The Rosseland approximations are used to describe the radiative heat flux in the energy equation. The model contains nonlinear coupled partial differential equations which have been transformed into ordinary differential equation by using the similarity variables. The relevant nonlinear equations have been solved by Runge-Kutta-Fehlberg fourth fifth-order method with shooting technique. The physical significance of interesting parameters on the flow and heat transfer characteristics as well as the local skin friction coefficient, wall couple stress, and the heat transfer rate are thoroughly examined.

Influence of Chemical Reaction on MHD Boundary Layer Flow of Nanofluids Over a Nonlinear Stretching Sheet with Thermal Radiation

Influence of Chemical Reaction on MHD Boundary Layer Flow of Nanofluids Over a Nonlinear Stretching Sheet with Thermal Radiation

Chemical reaction and heat transfer on boundary layer Maxwell Ferro-fluid flow under magnetic dipole with Soret and suction effects

In this article, the influence of chemical reaction and heat transfer analysis of Maxwell saturated Ferro-fluid flow over a stretching sheet under the influence of magnetic dipole with Soret and suction effects are investigated. The sheet is assumed to be permeable in a semi-infinite domain. Firstly, partial differential equations of mass, momentum and concentration for the governing flow problem are modelled and converted into a system of differential equations by utilizing similarity approach. Then the solution of resulting non-linear differential equations is solved by efficient Runge-Kutta technique based on shooting algorithm with the help of MATLAB. Effect of all appropriate parameters like ferromagnetic interaction parameter, chemical reaction parameter, Maxwell parameter, Soret number, suction parameter, Maxwell parameter, Schmidt number, and suction parameter on velocity, temperature and concentration field are confirmed through graphs and table. From the present conclusions, it is examined that by increasing the Maxwell parameter there is a decrease in the fluid velocity and boundary layer thickness. On the other hand, the uprising behaviour is prominent for both temperature and concentration profiles. Also predicted that there is an enhancement in skin friction coefficient and rate of heat transfer by enlarging suction parameter, but opposite trend is noted for Sherwood number. Also noted that the values of Prandtl are taken ranges from 0.72 to 10. The Nusselt number increases from 1.09 to 4.80.

Simulation of differential pulse polarography of irreversible EC mechanism

A reversible electrode reaction that is followed by totally irreversible chemical reaction is investigated theoretically. The influence of chemical reaction on two components of the net response of differential pulse polarogram is analyzed. It is demonstrated that this EC mechanism depends on two kinetic parameters and that their critical values can be used for the measurement of the rate constant of chemical reaction.

Influence of Chemical Reaction and Soret Effect on Mixed Convective MHD Oscillatory Flow of Casson Fluid with Thermal Radiation and Viscous Dissipation

In this paper the effects of thermal radiation, chemical reaction and Soret number on magnetohydrodynamic heat and mass transfer of a Casson fluid in the presence of magnetic field and viscous dissipation are analyzed. Perturbation technique has been used to convert the governing nonlinear partial differential equations into a ordinary linear differential equation and then solved analytically. The effects of physical parameters on velocity, temperature and concentration profiles are analyzed by plotting graphs and compared the present results with previously published results. It is observed from the results that the velocity profile increases with increase in the chemical reaction, thermal Grashof number and mass Grashof number but the opposite trends are seen with increase in the magnetic field parameter, Prandtl number and Schmidt number. Also, there is a tendency to increase the value of skin friction coefficient and the local Nusselt number with an increase in the Casson fluid parameter.

Comments on “Influence of chemical reaction and viscous dissipation on MHD mixed convection flow” by K. Das [JMST 28 (5) (2014) 1881~1885] and “Cu-water nanofluid flow and heat transfer over a shrinking sheet” by K. Das [JMST 28 (12) 5089~5094

In this letter, we submit our comment on the following recently published papers by Kalidas Das: (1) “Influence of chemical reaction and viscous dissipation on MHD mixed convection flow,” Journal of Mechanical Science and Technology 28 (5) (2014) 1881-1885; and (2) “Cu-water nanofluid flow and heat transfer over a shrinking sheet,” Journal of Mechanical Science and Technology 28 (12) (2014) 5089-5094. The authors attempt to present the similarity solutions in both papers. We comment that the similarity transformations considered in Refs. [1, 2] are incorrect. Thus, the results presented by Kalidas Das lead to invalid conclusions.

Numerical Solutions of Free Convective Flow from a Vertical Cone with Mass Transfer under the Influence of Chemical Reaction and Heat Generation/Absorption in the Presence of UWT/UWC

The purpose of this paper is to present a mathematical model for the combined effects of chemical reaction and heat generation/absorption on unsteady laminar free convective flow with heat and mass transfer over an incompressible viscous fluid past a vertical permeable cone with uniform wall temperature and concentration (UWT/UWC).The dimensionless governing boundary layer equations of the flow that are transient, coupled and non-linear partial differential equations are solved by an efficient, accurate and unconditionally stable finite difference scheme of Crank-Nicholson type. The velocity, temperature, and concentration profiles have been studied for various parameters viz., chemical reaction parameter , the heat generation and absorption parameter  , Schmidt number Sc , Prandtl number Pr , buoyancy ratio parameter N . The local as well as average skin friction, Nusselt number, Sherwood number, are discussed and analyzed graphically. The present results are compared with available results in open literature and are found to be in excellent agreement

Influence of Chemical Reaction and Thermal Radiation on Heat and Mass Transfer for Soret and Dufour's Effects on MHD Mixed Convection Hiemenz Flow of a Micropolar Fluid Embedded in a Porous Medium with Slip

Influence of Chemical Reaction and Thermal Radiation on Heat and Mass Transfer for Soret and Dufour's Effects on MHD Mixed Convection Hiemenz Flow of a Micropolar Fluid Embedded in a Porous Medium with Slip

Influence of chemical reaction, radiation and rotation on MHD nanofluid flow past a permeable flat plate in porous medium

In this paper we investigated an unsteady free convection flow of a nanofluid bounded by a moving vertical flat plate through porous medium in a rotating system with convective and diffusive boundary conditions. We considered two types of nanofluids namely Ag-water and TiO2-water. The governing equations are solved analytically by using perturbation technique. Finally the effects of various dimensionless parameters like magneticfield parameter, chemical reaction parameter, thermal radiation parameter, volume fraction of the nano particles and shape of the nano particles on velocity, temperature and concentration profiles along with the friction factor, local Nusselt and Sherwood numbers are discussed with the help of graphs. Comparisons of the present results made with the existed studies and found an excellent agreement under some special limited cases. Moreover, we observed that the rate of heat transfer in Ag-water nanofluid is higher than that of TiO2-water nanofluid and spherical shaped nano particles effectively enhances the heat transfer rate while compared with the cylindrical shaped nano particles.

Influence of chemical reactions on the nonlinear dynamics of dissipative flows

The nonlinear dynamics of resistive flow with a chemical reaction is studied. Proceeding from the Lagrangian description, the influence of a chemical reaction on the development of fluid singularities is considered.