Characteristics of Low Reynolds Number Shear-Free Turbulence at an Impermeable Base
Joint Authors
El-Shafie, Ahmed
Wan Mohtar, W. H. M.
Source
Issue
Vol. 2014, Issue 2014 (31 Dec. 2014), pp.1-10, 10 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2014-08-27
Country of Publication
Egypt
No. of Pages
10
Main Subjects
Medicine
Information Technology and Computer Science
Abstract EN
Shear-free turbulence generated from an oscillating grid in a water tank impinging on an impermeable surface at varying Reynolds number 74 ≤ R e l ≤ 570 was studied experimentally, where the Reynolds number is defined based on the root-mean-square (r.m.s) horizontal velocity and the integral length scale.
A particular focus was paid to the turbulence characteristics for low R e l < 150 to investigate the minimum limit of R e l obeying the profiles of rapid distortion theory.
The measurements taken at near base included the r.m.s turbulent velocities, evolution of isotropy, integral length scales, and energy spectra.
Statistical analysis of the velocity data showed that the anisotropic turbulence structure follows the theory for flows with R e l ≥ 117 .
At low R e l < 117 , however, the turbulence profile deviated from the prediction where no amplification of horizontal velocity components was observed and the vertical velocity components were seen to be constant towards the tank base.
Both velocity components sharply decreased towards zero at a distance of ≈ 1 / 3 of the integral length scale above the base due to viscous damping.
The lower limit where R e l obeys the standard profile was found to be within the range 114 ≤ R e l ≤ 116 .
American Psychological Association (APA)
Wan Mohtar, W. H. M.& El-Shafie, Ahmed. 2014. Characteristics of Low Reynolds Number Shear-Free Turbulence at an Impermeable Base. The Scientific World Journal،Vol. 2014, no. 2014, pp.1-10.
https://search.emarefa.net/detail/BIM-1050598
Modern Language Association (MLA)
Wan Mohtar, W. H. M.& El-Shafie, Ahmed. Characteristics of Low Reynolds Number Shear-Free Turbulence at an Impermeable Base. The Scientific World Journal No. 2014 (2014), pp.1-10.
https://search.emarefa.net/detail/BIM-1050598
American Medical Association (AMA)
Wan Mohtar, W. H. M.& El-Shafie, Ahmed. Characteristics of Low Reynolds Number Shear-Free Turbulence at an Impermeable Base. The Scientific World Journal. 2014. Vol. 2014, no. 2014, pp.1-10.
https://search.emarefa.net/detail/BIM-1050598
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1050598