scholarly journals Effect of Schmidt number in planar jet with chemical reaction by DNS

2021 ◽  
Author(s):  
Kenji KITO ◽  
Koji IWANO ◽  
Yasuhiko SAKAI ◽  
Yasumasa ITO
Keyword(s):  
Chemical Reaction ◽  
Schmidt Number ◽  
Planar Jet

S053035 Eddy Diffusivity and Turbulent Schmidt Number in a Reactive Planar Jet in Liquid Phase

2012 ◽  
Vol 2012 (0) ◽  
pp. _S053035-1-_S053035-3
Author(s):  
Tomoaki WATANABE ◽  
Yasuhiko SAKAI ◽  
Kouji NAGATA ◽  
Osamu TERASHIMA ◽  
Yasumasa ITO
Keyword(s):  
Liquid Phase ◽  
Schmidt Number ◽  
Eddy Diffusivity ◽  
Planar Jet ◽  
Turbulent Schmidt Number

MHD Convective Heat and Mass Transfer Flow of a Newtonian Fluid Past a Vertical Porous Plate with Chemical Reaction, Radiation Absorption and Thermal Diffusion

2015 ◽  
Vol 19 ◽  
pp. 37-56 ◽  
Author(s):  
M. Umamaheswar ◽  
M.C. Raju ◽  
S.V.K. Varma
Keyword(s):  
Chemical Reaction ◽  
Schmidt Number ◽  
Porous Plate ◽  
Radiation Absorption ◽  
Radiation Parameter ◽  
Reverse Effect ◽  
Reaction Parameter ◽  
Vertical Porous Plate ◽  
Transfer Flow ◽  
Chemical Reaction Parameter

In this manuscript, we have investigated the influence of radiation absorption on an unsteady MHD convective heat and mass transfer flow of a Newtonian fluid past a vertical porous plate in the presence of thermal radiation and chemical reaction. The non dimensional governing equations have been solved by using a multiple perturbation method, subject to the corresponding boundary conditions. The effects of various physical parameters such as velocity, temperature and concentration are studied through graphs. The expressions for local skin friction, Nusselt number and Sherwood number are derived and discussed with the help of a table. It is noticed that velocity increases when an increase in modified Grashof number Gm, radiation absorption parameter χ, Sorret number S0, time t whereas it decreases when an increase in Schmidt number Sc, chemical reaction parameter Kr and radiation parameter F. Temperature increases with an increase in radiation parameter χ and Sorret number S0whereas it decreases with an increase in chemical reaction parameter Kr, F and ϕ. Concentration is observed to be decreased when chemical reaction parameter Kr and Schmidt number Sc increase whereas it increases with an increase in Sorret number S0. Skin friction increases with an increase modified Grashof number Gm, radiation parameter χ and Sorret number S0whereas it has reverse effect in the case of Schmidt number Sc, chemical reaction parameter Kr. Nusselt number increases with an increase in Sc, S0, χ whereas it has reverse effect in the case of Kr. Sherwood number gets decreased when Sc, χ and Kr both are increased whereas it has shown revere effect in the case of S0.

scholarly journals Effect of Thermal Radiation and Chemical Reaction on MHD Flow of Blood in Stretching Permeable Vessel

2020 ◽  
Vol 25 (3) ◽  
pp. 198-211
Author(s):  
B. Zigta
Keyword(s):  
Blood Flow ◽  
Differential Equations ◽  
Thermal Radiation ◽  
Chemical Reaction ◽  
Schmidt Number ◽  
Hartmann Number ◽  
Time Dependent ◽  
Reaction Parameter ◽  
Linear Partial Differential Equations ◽  
Chemical Reaction Parameter

AbstractThis paper focuses on the theoretical analysis of blood flow in the presence of thermal radiation and chemical reaction under the influence of time dependent magnetic field intensity. Unsteady non linear partial differential equations of blood flow consider time dependent stretching velocity, the energy equation also accounts time dependent temperature of vessel wall and the concentration equation includes the time dependent blood concentration. The governing non linear partial differential equations of motion, energy and concentration are converted into ordinary differential equations using similarity transformations solved numerically by applying ode45. The effect of physical parameters, viz., the permeability parameter, unsteadiness parameter, Prandtl number, Hartmann number, thermal radiation parameter, chemical reaction parameter and Schmidt number on flow variables, viz., velocity of blood flow in vessel, temperature and concentration of blood, has been analyzed and discussed graphically. From the simulation study the following important results are obtained: velocity of blood flow increases with the increment of both permeability and unsteadiness parameter. The temperature of blood increases at the vessel wall as the Prandtl number and Hartmann number increase. Concentration of blood decreases as time dependent chemical reaction parameter and Schmidt number increases.

Reactive scalar field near the turbulent/non-turbulent interface in a planar jet with a second-order chemical reaction

2014 ◽  
Vol 26 (10) ◽  
pp. 105111 ◽  
Author(s):  
T. Watanabe ◽  
Y. Sakai ◽  
K. Nagata ◽  
Y. Ito ◽  
T. Hayase
Keyword(s):  
Scalar Field ◽  
Chemical Reaction ◽  
Second Order ◽  
Planar Jet ◽  
Order Chemical Reaction ◽  
Reactive Scalar

Turbulent Schmidt number and eddy diffusivity change with a chemical reaction

2014 ◽  
Vol 754 ◽  
pp. 98-121 ◽  
Author(s):  
Tomoaki Watanabe ◽  
Yasuhiko Sakai ◽  
Kouji Nagata ◽  
Osamu Terashima
Keyword(s):  
Chemical Reaction ◽  
Schmidt Number ◽  
Absorption Spectrometry ◽  
Eddy Diffusivity ◽  
Upstream Region ◽  
Reactive Flow ◽  
Measure Concentration ◽  
Mass Fluxes ◽  
Turbulent Schmidt Number ◽  
The Mean

AbstractWe provide empirical evidence that the eddy diffusivity$\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}D_{{t}\alpha }$and the turbulent Schmidt number${\mathit{Sc}}_{{t}\alpha }$of species$\alpha $($\alpha =\mathrm{A}, \mathrm{B}$or$\mathrm{R}$) change with a second-order chemical reaction ($\mathrm{A} + \mathrm{B} \rightarrow \mathrm{R}$). In this study, concentrations of the reactive species and axial velocity are simultaneously measured in a planar liquid jet. Reactant A is premixed into the jet flow and reactant B is premixed into the ambient flow. An optical fibre probe based on light absorption spectrometry is combined with I-type hot-film anemometry to simultaneously measure concentration and velocity in the reactive flow. The eddy diffusivities and the turbulent Schmidt numbers are estimated from the simultaneous measurement results. The results show that the chemical reaction increases${\mathit{Sc}}_{t\mathrm{A}}$;${\mathit{Sc}}_{t\mathrm{B}}$is negative in the region where the mean concentration of reactant B decreases in the downstream direction, and is positive in the non-reactive flow in the entire region on the jet centreline. It is also shown that${\mathit{Sc}}_{t\mathrm{R}}$is positive in the upstream region whereas it is negative in the downstream region. The production terms of axial turbulent mass fluxes of reactant B and product R can produce axial turbulent mass fluxes opposite to the axial gradients of the mean concentrations. The changes in the production terms due to the chemical reaction result in the negative turbulent Schmidt number of these species. These results imply that the gradient diffusion model using a global constant turbulent Schmidt number poorly predicts turbulent mass fluxes in reactive flows.

scholarly journals Similarity analysis for natural convection from a vertical plate with distributed wall concentration

2000 ◽  
Vol 23 (5) ◽  
pp. 319-334 ◽  
Author(s):  
I. Mulolani ◽  
M. Rahman
Keyword(s):  
Natural Convection ◽  
Chemical Reaction ◽  
Schmidt Number ◽  
Vertical Plate ◽  
Reaction Order ◽  
Similarity Solutions ◽  
Convection Flow ◽  
Fundamental Parameters ◽  
Runge Kutta Method ◽  
Convection Layer

Steady laminar natural convection flow over a semi-infinite vertical plate is examined in this paper. It is assumed that the concentration of a species along the plate follows some algebraic law with respect to chemical reaction. Similarity solutions may then be obtained for different orders of reaction. The fundamental parameters of this problem are the Schmidt number, Sc, and reaction order,n. Numerical results, based on the fourth order Runge-Kutta method, for Schmidt number ranging from0.0to100.0and reaction order from0.0to1.5are presented. When chemical reaction occurs, diffusion and velocity domains are seen to expand out from the plate. For large values ofn, one may expect a smaller diffusion layer which, at fixed Schmidt number, is associated with increased velocity and reduced convection-layer.

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.

Free convection flow with chemical reaction effect between oscillating parallel plates

2021 ◽  
Vol 2 (2) ◽  
pp. 52-59
Author(s):  
F. Zulkiflee ◽  
S. Shafie ◽  
A. Ali ◽  
A.Q. Mohamad
Keyword(s):  
Free Convection ◽  
Prandtl Number ◽  
Skin Friction ◽  
Chemical Reaction ◽  
Schmidt Number ◽  
Convection Flow ◽  
Parallel Plates ◽  
Free Convection Flow ◽  
Transform Method ◽  
Grashof Number

This research purpose is to investigate the exact solutions for unsteady free convection flow between oscillating parallel plates with mass diffusion and chemical reaction. The governing equations are modelled and reduced using non-dimensional variables. The method used is Laplace transform method. Solutions for velocity, temperature, and concentration fields as well as skin friction, Nusselt and Sherwood number are obtained. For physical understanding, analytical results for velocity, temperature and concentration profile are plotted graphically with respect to the Schmidt number, Prandtl number, oscillating parameter, Grashof number, mass Grashof number and chemical reaction parameter. Increasing Prandtl number and Schmidt number decreases the concentration, velocity, temperature, and skin friction but increases the Sherwood and Nusselt numbers.

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