Second order fully discrete defect-correction scheme for nonstationary conduction-convection problem at high Reynolds number

2016 ◽  
Vol 33 (3) ◽  
pp. 681-703 ◽  
Author(s):  
Haiyan Su ◽  
Xinlong Feng ◽  
Yinnian He
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Second Order ◽  
Defect Correction ◽  
Fully Discrete ◽  
Correction Scheme ◽  
Convection Problem ◽  
High Reynolds

Spectral energy transfer in high Reynolds number turbulence

1977 ◽  
Vol 79 (2) ◽  
pp. 337-359 ◽  
Author(s):  
K. N. Helland ◽  
C. W. Van Atta ◽  
G. R. Stegen
Keyword(s):  
Reynolds Number ◽  
Energy Transfer ◽  
Energy Spectrum ◽  
High Reynolds Number ◽  
Reynolds Numbers ◽  
Second Order ◽  
Spectral Energy ◽  
Local Isotropy ◽  
High Reynolds ◽  
Good Agreement

The spectral energy transfer of turbulent velocity fields has been examined over a wide range of Reynolds numbers by experimental and empirical methods. Measurements in a high Reynolds number grid flow were used to calculate the energy transfer by the direct Fourier-transform method of Yeh & Van Atta. Measurements in a free jet were used to calculate energy transfer for a still higher Reynolds number. An empirical energy spectrum was used in conjunction with a local self-preservation approximation to estimate the energy transfer at Reynolds numbers beyond presently achievable experimental conditions.Second-order spectra of the grid measurements are in excellent agreement with local isotropy down to low wavenumbers. For the first time, one-dimensional third-order spectra were used to test for local isotropy, and modest agreement with the theoretical conditions was observed over the range of wavenumbers which appear isotropic according to second-order criteria. Three-dimensional forms of the measured spectra were calculated, and the directly measured energy transfer was compared with the indirectly measured transfer using a local self-preservation model for energy decay. The good agreement between the direct and indirect measurements of energy transfer provides additional support for both the assumption of local isotropy and the assumption of self-preservation in high Reynolds number grid turbulence.An empirical spectrum was constructed from analytical spectral forms of von Kármán and Pao and used to extrapolate energy transfer measurements at lower Reynolds number to Rλ = 105 with the assumption of local self preservation. The transfer spectrum at this Reynolds number has no wavenumber region of zero net spectral transfer despite three decades of $k^{-\frac{5}{3}}$. behaviour in the empirical energy spectrum. A criterion for the inertial subrange suggested by Lumley applied to the empirical transfer spectrum is in good agreement with the $k^{-\frac{5}{3}}$ range of the empirical energy spectrum.

SWIMMING OF A SINGLY FLAGELLATED MICROORGANISM IN A MAGNETOHYDRODYNAMIC SECOND-ORDER FLUID

2017 ◽  
Vol 17 (01) ◽  
pp. 1750009 ◽  
Author(s):  
M. SAJID ◽  
N. ALI ◽  
O. ANWAR BÉG ◽  
A. M. SIDDIQUI
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Body Force ◽  
Magnetic Parameter ◽  
Green Energy ◽  
Second Order ◽  
Viscous Force ◽  
Electrically Conducting ◽  
Magnetic Body Force ◽  
High Reynolds

Magnetic swimming is rapidly attracting interest in biomedical engineering applications. In the present work, we study the swimming of a singly flagellated microorganism propelling in an electrically-conducting magnetohydrodynamic (MHD) viscoelastic second-order fluid. The singly flagellated microorganism is modeled by a transversely waving infinite flexible sheet. The method of successive approximation is employed up to second-order in the amplitude of oscillation of the waving sheet. It has been shown that the velocity induced by a transversely waving infinite flexible sheet in a viscoelastic second-order fluid decreases with the elastic property for all the values of the Reynolds number. The solution reveals that the magnetic parameter (relating the relative influence of magnetic body force and viscous force effects) increases the propulsion for small Reynolds number and reduces it with high Reynolds number. The influence of magnetic field is therefore variable depending on the inertial effect. Comparisons with the literature demonstrate the generality of the proposed approach which allows errors included in previous formulations to be corrected. The present results may be, in principle, taken as a benchmark for computational modeling of magnetic swimming in viscoelastic fluids of relevance to green energy and magnetic biomedical procedures.

Evaluation of methods for characterizing surface topography of models for high Reynolds number wind-tunnels

1982 ◽  
Author(s):  
E. TEAGUE ◽  
T. VORBURGER ◽  
F. SCIRE ◽  
S. BAKER ◽  
S. JENSEN ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Surface Topography ◽  
High Reynolds Number ◽  
Wind Tunnels ◽  
High Reynolds ◽  
Evaluation Of Methods

Modeling and Simulation of High Reynolds' Number Flows During Reaction Injection Mold Filling

1994 ◽  
Vol 9 (3) ◽  
pp. 279-285 ◽  
Author(s):  
Rahima K. Mohammed ◽  
Tim A. Osswald ◽  
Timothy J. Spiegelhoff ◽  
Esther M. Sun
Keyword(s):  
Reynolds Number ◽  
Modeling And Simulation ◽  
High Reynolds Number ◽  
Mold Filling ◽  
Injection Mold ◽  
High Reynolds ◽  
Reynolds Number Flows
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