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Three Dimensional Concentration Fields in the Near-Wake of Anthropomorphic Mannequins in Uniform Freestreams and Assessment of Vortex Shedding as a Mass Transfer Mechanism.

Authors
Flynn-MR
Source
Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 1990 Feb:18 pages
Link
NIOSHTIC No.
00198532
Abstract
Studies were conducted on the spatial distribution of concentration in the vicinity of an anthropometric mannequin in a uniform freestream. A set of concentration measurements was performed to obtain the spatial distribution of concentration with the fixed source placed in their recirculation zone. Sulfur-hexafluoride was used as a tracer gas. Eight isocontour maps were generated by using the results of the study. The heights of the planes were approximately the positions near the navel, the heart and the mouth of the mannequin. Results indicated that the three dimensional concentration field downstream of workers in uniform freestreams is unlikely to be very well mixed if the source is in the near/wake and that vortex shedding is experimentally observed over certain regions of the body but not in others. From the experimental results obtained in this study and those taken from the literature, the authors suggest that a mannequin can be divided into three regions with respect to vortex shedding: the free end region (from the top to the neck) characterized by a down wash effect, the intermediate region (from the chest to the elbows) characterized by the combination of the down wash effect and the vortex shedding, and the vortex shedding region (from the waist to the knee) characterized by the vortex shedding.
Keywords
NIOSH-Grant; Control-technology; Air-contamination; Fluid-mechanics; Air-flow;
Contact
Environmental Sciences & Engr University of North Carolina Rosenau Hall 201H Chapel Hill, NC 27514
Publication Date
19900201
Document Type
Final Grant Report;
Funding Amount
113206.00
Funding Type
Grant;
Fiscal Year
1990
NTIS Accession No.
PB91-197509
NTIS Price
A03
Identifying No.
Grant-Number-R01-OH-02392
NIOSH Division
OEP
Priority Area
Control Technology and Personal Protective Equipment; Research Tools and Approaches; Control-technology;
Source Name
Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina
State
NC;
Performing Organization
University of North Carolina Chapel Hill, Chapel Hill, North Carolina
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