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Record Details

Record 13 of 38797
Absolute instability of the Gaussian wake profile
External Online Source: doi:10.1063/1.866470
Author and Affiliation:
Hultgren, Lennart S.(NASA Lewis Research Center, Cleveland, OH, United States)
Aggarwal, Arun K.(Illinois Institute of Technology, Chicago, United States)
Abstract: Linear parallel-flow stability theory has been used to investigate the effect of viscosity on the local absolute instability of a family of wake profiles with a Gaussian velocity distribution. The type of local instability, i.e., convective or absolute, is determined by the location of a branch-point singularity with zero group velocity of the complex dispersion relation for the instability waves. The effects of viscosity were found to be weak for values of the wake Reynolds number, based on the center-line velocity defect and the wake half-width, larger than about 400. Absolute instability occurs only for sufficiently large values of the center-line wake defect. The critical value of this parameter increases with decreasing wake Reynolds number, thereby indicating a shrinking region of absolute instability with decreasing wake Reynolds number. If backflow is not allowed, absolute instability does not occur for wake Reynolds numbers smaller than about 38.
Publication Date: Nov 01, 1987
Document ID:
19880033615
(Acquired Nov 28, 1995)
Accession Number: 88A20842
Subject Category: FLUID MECHANICS AND HEAT TRANSFER
Document Type: Journal Article
Publication Information: Physics of Fluids (ISSN 0031-9171); 30; 3383-338
Publisher Information: United States
Financial Sponsor: NASA; United States
Organization Source: NASA Lewis Research Center; Cleveland, OH, United States
Illinois Inst. of Tech.; Chicago, IL, United States
Description: 5p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: FLOW STABILITY; FLOW VELOCITY; NORMAL DENSITY FUNCTIONS; VELOCITY DISTRIBUTION; VISCOUS FLOW; WAKES; COMPUTATIONAL FLUID DYNAMICS; REYNOLDS NUMBER
Imprint And Other Notes: Physics of Fluids (ISSN 0031-9171), vol. 30, Nov. 1987, p. 3383-3387. Research supported by the Illinois Institute of Technology.
Miscellaneous Notes: Research supported by the Illinois Institute of Technology
Availability Source: Other Sources
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