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Journal of Flow Visualization and Image Processing
SJR: 0.161 SNIP: 0.312 CiteScore™: 0.1

ISSN Print: 1065-3090
ISSN Online: 1940-4336

Journal of Flow Visualization and Image Processing

DOI: 10.1615/JFlowVisImageProc.v6.i2.40
pages 115-128

DETAILED HEAT TRANSFER DISTRIBUTIONS IN A TRIANGULAR DUCT WITH AN ARRAY OF TANGENTIAL JETS

Jenn-Jiang Hwang
Department of Mechanical Engineering, Chung-Hua University, Hsinchu, Taiwan 300, Republic of China
Chung-Shen Cheng
Department of Mechanical Engineering, Chung-Hua University, Hsinchu, Taiwan 300, Republic of China

ABSTRACT

Heat transfer characteristics in a triangular duct cooled by an array of side-entry tangential jets has been studied experimentally. A right-angle triangular duct with an apex angle of 45° is tested under different jet Reynolds numbers and jet spacing. Coolant is provided by an array of equally spaced wall jets aimed at the leading-edge apex and exits from the radial outlet. Detailed heat transfer coefficients are measured for the two walls forming the apex, using a transient liquid-crystal technique. Secondary flow structures are visualized to realize the mechanism of heat transfer enhancement by swirl jets. Results show that an increase in the jet Reynolds number increases the heat transfer on both walls. Moreover, local heat transfer on both walls gradually decreases downstream due to the crossflow effect. Finally, area-averaged heat transfer coefficients on both walls have been correlated with the jet Reynolds number.