Effects of Schmidt Number on Turbulent Mass Transfer Around a Rotating Circular Cylinder

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Dong-Hyeog Yoon ◽  
Kyung-Soo Yang ◽  
Klaus Bremhorst
Keyword(s):  
Mass Transfer ◽  
Circular Cylinder ◽  
Diffusion Layer ◽  
Time Scale ◽  
Schmidt Number ◽  
Concentration Field ◽  
Limiting Behavior ◽  
Rotating Circular Cylinder ◽  
Scale Ratio ◽  
Turbulent Mass Transfer

Characteristics of turbulent mass transfer around a rotating circular cylinder have been investigated by Direct Numerical Simulation. The concentration field was computed for three different cases of Schmidt number, Sc = 1, 10 and 100 at ReR* = 336. Our results confirm that the thickness of the Nernst diffusion layer decreases as Sc increases. Wall-limiting behavior within the diffusion layer was examined and compared with that of channel flow. Concentration fluctuation time scale was found to scale with r+2, while the time scale ratio nearly equals the Schmidt number throughout the diffusion layer. Scalar modeling closure constants based on gradient diffusion models were found to vary considerably within the diffusion layer. Results of an octant analysis show the significant role played by the ejection and sweep events just as is found for flat plate, channel, and pipe flow boundary layers. Turbulence budgets revealed a strong Sc dependence of turbulent scalar transport.

Effects of Schmidt Number on Turbulent Mass Transfer Around a Rotating Circular Cylinder

2010 ◽  
Author(s):  
Dong-Hyeog Yoon ◽  
Kyung-Soo Yang ◽  
Kyongjun Lee ◽  
Klaus Bremhorst
Keyword(s):  
Mass Transfer ◽  
Circular Cylinder ◽  
Diffusion Layer ◽  
Schmidt Number ◽  
Concentration Field ◽  
Limiting Behavior ◽  
Rotating Circular Cylinder ◽  
Nernst Diffusion Layer ◽  
Scale Ratio ◽  
Turbulent Mass Transfer

Characteristics of turbulent mass transfer around a rotating circular cylinder have been investigated by Direct Numerical Simulation. The concentration field was computed for three different cases of Schmidt number, Sc = 1, 10 and 100 at Re* = 336. Our results confirm that the thickness of the Nernst diffusion layer decreases as Sc increases. Wall-limiting behavior within the Nernst diffusion layer was examined and compared with those of channel flow. Concentration fluctuation was found to be time-scaled with (r+)2 while the time scale ratio equals the Schmidt number throughout the Nernst diffusion layer. Scalar modeling closure constants were determined, and turned out to vary considerably within the diffusion layer.

Direct Numerical Simulation of Turbulent Flow and Mass Transfer Around a Rotating Circular Cylinder

2005 ◽  
Author(s):  
Jong-Yeon Hwang ◽  
Kyung-Soo Yang ◽  
Klaus Bremhorst
Keyword(s):  
Numerical Simulation ◽  
Mass Transfer ◽  
Reynolds Number ◽  
Circular Cylinder ◽  
Direct Numerical Simulation ◽  
Turbulent Flow ◽  
Friction Velocity ◽  
Concentration Field ◽  
Rotating Circular Cylinder ◽  
Instantaneous Concentration

Characteristics of turbulent flow and mass transfer around a rotating circular cylinder are investigated by Direct Numerical Simulation. Mass-transfer results are presented at a high Schmidt number (Sc = 1670). The concentration field is computed for three different cases of low Reynolds number, Re*R = 161, 348 and 623, based on the cylinder radius and friction velocity. Results confirm that the thickness of Nernst diffusion layer is very small compared with that of viscous sub-layer in the case of high Sc mass transfer. A strong correlation of the concentration field with streamwise and vertical velocity components is noticed. However, that is not the case with the spanwise velocity component. Visualization of instantaneous concentration reveals that the length scale of concentration fluctuation typically decreases as Reynolds number increases. The correlation between Sherwood number and Reynolds number is consistent with other experiments currently available.

A contribution to the problem of turbulent mass transfer at high values of the Schmidt number and to the hydrodynamics of the turbulent boundary layer

1986 ◽  
Vol 51 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Václav Kolář ◽  
František Vašák ◽  
Zdeněk Brož
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Mass Transfer ◽  
Turbulent Boundary Layer ◽  
Transition Layer ◽  
Schmidt Number ◽  
Interface Parameters ◽  
Turbulent Mass Transfer

It has been shown in the paper that under the turbulence (Re > 104) and at high values of the Schmidt number (Sc > 103), when the principal resistance to mass transfer is concentrated in the laminar layer immediately adhering to the interface, significant instabilities appear induced by the turbulent disturbances in the neighbouring transition layer, or by the discontinuities at the interface. Parameters have been determined characterizing this phenomenon on the basis of experimental data and their values have been compared with the data published in the literature as characteristics of the periodic viscous sublayers.

Transient Heat and Mass Transfer of Micropolar Fluid between Porous Vertical Channel with Boundary Conditions of Third Kind

2016 ◽  
Vol 17 (5) ◽  
pp. 231-242 ◽  
Author(s):  
D. H. Doh ◽  
M. Muthtamilselvan ◽  
D. Prakash
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Micropolar Fluid ◽  
Schmidt Number ◽  
Concentration Field ◽  
Vertical Channel ◽  
Physical Parameters ◽  
Incompressible Micropolar Fluid ◽  
Implicit Finite Difference ◽  
Biot Numbers

AbstractAn investigation of heat and mass transfer characteristics of unsteady free convective flow of viscous incompressible micropolar fluid between the vertical porous plates in the presence of thermal radiation is carried out in the present work. The fluid is considered to be grey, absorbing–emitting but non scattering medium and the Cogley–Vincent–Gilles formulation is adopted to simulate the radiation component of heat transfer. The resulting system of equations is solved numerically with Crank–Nicolson implicit finite difference method. The effects of various physical parameters such as transient, micropolar parameter, radiation parameter, Reynolds number, Schmidt number, heat and mass transfer Biot numbers on the velocity, temperature and concentration field are discussed graphically.

Influence of Schmidt number on the fluctuations of turbulent mass transfer to a wall

AIChE Journal ◽  
1977 ◽  
Vol 23 (2) ◽  
pp. 160-169 ◽  
Author(s):  
Dudley A. Shaw ◽  
Thomas J. Hanratty
Keyword(s):  
Mass Transfer ◽  
Schmidt Number ◽  
Turbulent Mass Transfer
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