Visualization of effect of turbulators on local heat transfer distribution in a 180 degree turn with liquid crystals /

10,000 and 38,000. The results are presented as constant

Bibliographic Details
Main Author: Rajesh, Gopal
Format: Thesis eBook
Language:English
Published: [Place of publication not identified] : [publisher not identified] ; 1994.
Subjects:
Online Access:Link to OAKTrust copy
Description
Summary:10,000 and 38,000. The results are presented as constant
45' ribs. In the lower Reynolds number cases, there are
450 ribs cause the heat transfer distributions in the sharp
advantageous to have the angled ribs in the after-tum region
angled ribs is directed toward the inner wall. The crossed
around the 180' turn is influenced by flow impingement, flow
attack of 45', 90', and, 135', and Reynolds numbers of about
cooling passages in modern gas turbine blades. Results are
depending on the orientation of the ribs. In the after-tum
generally higher compared with that in the before-tum region.
generally lower heat transfer in the sharp turn than the V-
in the ribbed walls and the smooth walls in the two straight
in the turn. The 90' ribs increase not only the heat transfer
inner wall. The heat transfer in the after-turn region is
larger variations of the heat transfer distributions in the
Liquid crystal experiments have been conducted to study the
Nusselt number lines on the surface of one of the principal
obtained for a rib height-to-channel hydraulic diameter ratio
of 0.0625, a rib pitch-to-height ratio of 10, angles-of-
oriented in such a way that secondary flow caused by the
parallel rib cases. They have generally lower thermal
passes of the test channel, but also the heat transfer in the
performance than the parallel 45' ribs. Between consecutive
recirculation, secondary flow induced by centrifugal force at
region, the main flow is forced toward the outer wall. It is
regions of high heat transfer near the upstream ends of the
ribs do not perform as well as the V-450 ribs and cause
ribs. The high heat transfer regions may be near the outer
ribs. The rib-roughened channel models the serpentine
sharp turn.
sharp turn. Between consecutive parallel 450 ribs, there are
than both the parallel 45' ribs and the 900 ribs. The V-135'
the turn, and flow separation at the tip of the divider or
The V-450 ribs cause higher heat transfer in the sharp turn
There is a small recirculation zone at the first outer corner
turbulent heat transfer for fully developed flow of air in a
turn to be quite different from those in the corresponding
two-pass square channel with two opposite walls roughened
V-450 ribs, there is a large region of high heat transfer.
wall or near the inner wall in the two-pass channel,
walls of the test section. The smooth channel heat transfer
with parallel and cross arrays of full ribs and with V-shaped
Item Description:"Major subject: Mechanical Engineering".
In title, symbols are used.
Vita.
Physical Description:xi, 68 leaves : illustrations ; 28 cm.
Also available online.
Bibliography:Includes bibliographical references.