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Affiliation of Author(s):能源与动力学院

Journal:INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER

Key Words:Conjugated heat transfer Confined jet impingement Wedge-shaped concave surface Corrugated impinging plate Heating effectiveness

Abstract:An experimental and numerical investigation is conducted to study the conjugated heat transfer performance on the leading edge of a wedge-shaped concave wall subjected to external cold flow and internal hot jets impingement. A corrugated impinging plate with an extended front-extended port inside the concave cavity is proposed for the purpose of heat transfer enhancement. The effects of corrugation length-to-diameter ratio (H-j/d) ranging from 5 to 11 and width-to-diameter ratio (W-j/d) ranging from 2.5 to 6 on the conjugated heat transfer performance are examined under some representative jet Reynolds numbers (Re-j) in the range of 7900-31,700. The results show that the corrugated impinging plate has a significant impact on improving the conjugated heat transfer performance in the vicinity of concave wall leading edge. The presence of corrugation plays two roles by reducing the jet impinging distance on one hand and aggravating the jet confinement on the other hand. Therefore, it produces more complicated jet impinging flow and convective heat transfer behaviors than the baseline case without corrugation. According to the tested results, the specified area-averaged heating effectiveness is increased approximately 6.3%-18.8% under Re-j = 7900 and 2.5%-9.4% Under Re-j = 31,700 respectively by increasing the corrugation length when Wj/d is fixed as 2.5. The specified area-averaged heating effectiveness is increased approximately 16.1%-22.1% under Re-j = 7900 and 7.7%-12.7% under Re-j = 31,700 respectively by increasing the corrugation width when H-j/d is fixed as 9. In general, the corrugation with larger length and width seems to perform the better heating effectiveness over the entire concave surface. The enhancement of heating effectiveness related to the baseline case behaves more significantly under a smaller jet Reynolds number.

ISSN No.:0735-1933

Translation or Not:no

Date of Publication:2017-10-01

Co-author:Guan Tao,Shan Yong

Correspondence Author:zjz