SBIR 95-1 SOLICITATION
HEAT TRANSFER ENHANCEMENT IN TURBINE BLADES WITH ASYMMETRIC RIBS
Gas turbines are required to operate with gas flows at temperatures more than 1400oC, much
higher than the melting temperatures of the blade material. The Coriolis force, induced by
rotation of turbine blades, results in highly non-uniform heat transfer distribution on leading
and trailing sides, leading to premature failure and unreliable thermal operation of the blade.
This is mainly due to the distortion of mainstream velocity profile by cross-stream secondary
flows. To combat this problem, use of Asymmetric ribs are proposed for heat transfer
augmentation, namely, thicker ribs on trailing side and thinner ribs on leading side. It is
anticipated that higher shear stress along the leading wall and lower shear stress on the leading
wall, enforced by asymmetric ribs, will yield enhanced and more uniform heat transfer.
The proposed investigation aims at obtaining uniform distributions of regional and local heat
transfer coefficients through mass transfer experiments and by using the analogy between heat
and mass transfer. Extensive experiments will be conducted with transverse and angled,
asymmetric ribs in a two-pass, square rotating channel. The local distributions obtained will
determine the extent of uniformity and enhancement of heat transfer with asymmetric ribs. A
wide number of operating and geometrical parameters will be examined. The proposed Phase I
project will identify the best rib configuration that can yield enhanced and more uniform heat
transfer in turbine blades.
Potential Commercial Applications:
The for asymmetric ribs include gas turbine blades for
aircraft engines and rotors of electrical rotating machinery. It will lead to higher power output,
higher thermal efficiency, and increased life cycle of gas turbine engines and turbomachinery.
Name and Address of Offeror:
7610 Eastmark Drive, Suite 105
College Station, Texas 77840
Small Business Innovation Research Program (SBIR) &
Small Business Technology Transfer Program (STTR) Programs
Electronic Management System (EMS)
National Aeronautics and Space Administration (NASA)
The SBIR/STTR EMS site is maintained by Steve
Hu, Hughes STX.
For comments and questions, contact
Updated: Feb. 7, 1996