Local heat transfer distributions in a square channel with solid and perforated ribs on two opposite walls

Book · Tue Dec 31 04:00:00 EST 1996

OSTI ID:445519

Kukreja, R T ^[1]; Lau, S C ^[2]

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1. Lynntech Inc., College Station, TX (United States)
2. Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering

In this experimental investigation, the variations of the local heat transfer coefficient in rib-roughened turbine blade internal cooling passages are examined. Using liquid crystal thermometry, the detailed local heat transfer distributions are determined for turbulent flow through a long, straight, square test channel model with ribs of various configurations, including perforated ribs, on two opposite walls. Angled and V-shaped solid ribs enhance more heat transfer than transverse solid ribs. Angled solid ribs cause very large spanwise variations of the local heat transfer distribution. With the highest overall heat transfer and relatively small spanwise heat transfer variation, V-shaped ribs are recommended for internal cooling of gas turbine blades. Perforated ribs enhance less heat transfer than solid ribs, because the jet streams leaving the holes interrupt and weaken flow reattachment on the wall downstream of a rib. Increasing the size or the number of holes, or the total hole area, lowers the overall heat transfer.

• Sponsoring Organization: National Aeronautics and Space Administration, Washington, DC (United States)
• OSTI ID: 445519
• Report Number(s): CONF-961105--; ISBN 0-7918-1520-X
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
AUGMENTATION
COOLING SYSTEMS
EXPERIMENTAL DATA
GAS TURBINE ENGINES
HEAT TRANSFER
TURBINE BLADES
TURBULENT FLOW