Citation
Laufer, John (1948) Investigation of turbulent flow in a two-dimensional channel. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/6ZYC-HJ88. https://resolver.caltech.edu/CaltechETD:etd-09152005-133021
Abstract
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A detailed exploration of the field of mean and fluctuating quantities in a two-dimensional turbulent channel flow is presented. The measurements were repeated at three Reynolds numbers, 1.23 x 10(5), 3.08 x 10(5) and 6.16 x 10(5), based on the half width of the channel and the maximum velocity. A channel of 5" width and 12:1 aspect ratio was used for the investigation.
Mean speed and axial fluctuation measurements were made well within the laminar sublayer. The semi-theoretical predictions concerning the extent of the laminar sublayer were confirmed. It was found that the viscosity has a more profound influence on the fluctuations than on the mean velocity, the region of influence being approximately four times as wide.
Fluctuations perpendicular to the flow direction [...] and the correlation coefficient [...] were measured, and the turbulent shear distribution calculated. Shear calculations from independent methods using the measured velocity gradient at the wall and pressure gradient along the channel furnished a good check on the values of the shearing stress in all cases with the exception of the highest Reynolds number where [...] obtained from the fluctuation measurements is approximately 25% lower. All mean fluctuating quantities were found to decrease with increasing Reynolds number. Measurements of the scales [...], [...] and micro-scales of turbulence [...] across the channel are presented and their variation with Reynolds number is discussed. Using a new technique, values for [...] were obtained; a method for estimating [...] is also given.
The energy balance in the turbulent flow field was calculated from the measured quantities. From this calculation it is posssible to give a descriptive picture of turbulent energy diffusion in the center portion of the channel cross-section.
Item Type: | Thesis (Dissertation (Ph.D.)) |
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Degree Grantor: | California Institute of Technology |
Division: | Engineering and Applied Science |
Major Option: | Aeronautics |
Thesis Availability: | Public (worldwide access) |
Research Advisor(s): |
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Group: | GALCIT |
Thesis Committee: |
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Defense Date: | 1 January 1948 |
Record Number: | CaltechETD:etd-09152005-133021 |
Persistent URL: | https://resolver.caltech.edu/CaltechETD:etd-09152005-133021 |
DOI: | 10.7907/6ZYC-HJ88 |
Default Usage Policy: | No commercial reproduction, distribution, display or performance rights in this work are provided. |
ID Code: | 3549 |
Collection: | CaltechTHESIS |
Deposited By: | Imported from ETD-db |
Deposited On: | 16 Sep 2005 |
Last Modified: | 21 Dec 2019 04:57 |
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