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Flow Visualizations in a Packed Bed of Twisted Tapes A videotape presentation of the flow field in a packed bed of 48 twisted tapes which can be simulated by very thin virtual cylinders has been assembled. The indices of refraction of the oil and the Lucite twisted tapes were closely matched, and the flow was seeded with magnesium oxide particles. Planar laser light projected the flow field in two dimensions both along and transverse to the flow axis. The flow field was three dimensional and complex to describe, yet the most prominent finding was flow threads. It appeared that axial flow spiraled along either within the confines of a virtual cylindrical boundary or within the exterior region, between the tangency points, of the virtual cylinders. Random packing and bed voids created vortices and disrupted the laminar flow but minimized the entrance effects. The flow-pressure drops in the packed bed fell below the Ergun model for porous-media flows. Single-twisted-tape results of Smithberg and Landis (1964) were used to guide the analysis. In appendix A the results of several investigators are scaled to the Ergun model. Further investigations including different geometric configurations, computational fluid dynamic (CFD) gridding, and analysis are required.
Document ID
20140000374
Acquisition Source
Glenn Research Center
Document Type
Presentation
Authors
Hendricks, R. C.
(NASA Glenn Research Center Cleveland, OH, United States)
Braun, M. J.
(Akron Univ. Akron, OH, United States)
Date Acquired
January 23, 2014
Publication Date
November 1, 2002
Subject Category
Fluid Mechanics And Thermodynamics
Report/Patent Number
NASA/TM-2002-208914
Meeting Information
Meeting: Pacific Symposium on Flow Visualizaiton and Image Processing
Location: Honolulu, HI
Country: United States
Start Date: May 16, 1999
End Date: May 19, 1999
Sponsors: Pacific Centre of Thermal Fluids Engineering
Funding Number(s)
PROJECT: RTOP 910-30-11
Distribution Limits
Public
Copyright
Public Use Permitted.

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