A study of Nusselt number distributions in a curved channel.
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Authors
Schallert, Anthony R.
Subjects
curved heating channel
heat transfer coefficients
Nusselt numbers
Dean vortices
centrifugal instabilities
heat transfer coefficients
Nusselt numbers
Dean vortices
centrifugal instabilities
Advisors
Ligrani, Phillip M.
Date of Issue
1992-06
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
The effects of curvature and the resulting centrifugal instabilities on local heat transfer distributions are
studied in a curved channel with a rectangular cross section and a 40 to 1 aspect ratio at Dean numbers
from 100 to 278. The experimental conditions are identified for which forced convection with weak
buoyancy, and forced convection with strong buoyancy are present. With weak buoyancy effects present
(Re2/Gr > 50 x 10-6
) a new method is developed to deduce forced convection Nusselt numbers without the
influence of natural convection. Resulting data provide information on the influence of Dean vortex pair
and their secondary flows. For a Dean number of 275, Nusselt numbers measured on the concave surface
are higher than the ones on the convex surface through out the curved portion, for X/D from 130 to 230,
where X is the distance from the start of the heated section, and D is the width of the channel. For Dean
numbers from 175 to 250, Nusselt numbers are higher on the concave surface than on the convex surface
for X/D from 160 to 230, such that differences increase with Dean number.
Type
Thesis
Description
Series/Report No
Department
Mechanical Engineering
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
Funder
Format
144 p.;28 cm.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.