Heat transfer in rotating narrow rectangular ducts with heated sides oriented at 60 degrees to the r-z plane

Gas turbine blade life is often limited by the effectiveness of the cooling in the trailing edge convective cavity, which generally has a narrow cross -section. Previous research on rotational effects considered cavity shapes quite different from those of typical trailing edge cavities. In this resea rch, experiments were conducted to deter-mine the effect of rotation on hea t transfer in ducts of narrow cross-section (height-to-width ratio of 1:10) , oriented with the heated sides at 60 degrees to the r-z plane. in the exp eriment, a high-molecular-weight gas (Refrigerant- 134A) at ambient pressur e and temperature conditions was used to match the dimensionless parameters at engine conditions. Thin foil heaters were used to produce a constant he ar flux at the long sides of the duct; the narrow sides were unheated. Duct Reynolds numbers were varied np to 20,000; rotation numbers were varied re p to 0.25. The rest results show the effect of rotation and aspect ratio on duct leading and trailing side heat transfer. In addition, the results sha w the variation in heat transfer coefficient with transverse location in th e duct, demonstrating the effect of rotation not only on lead and trail sid e heat transfer, but also on forward and aft end heat transfer.