TY - JOUR
T1 - Experimental investigation on the cooling performance of multi-row film holes of a serpentine nozzle
AU - Shi, Jingwei
AU - Hui, Zhonghao
AU - Zhou, Li
AU - Wang, Zhanxue
AU - Liu, Yongquan
N1 - Publisher Copyright:
© 2025 Elsevier Ltd
PY - 2025/4/1
Y1 - 2025/4/1
N2 - There are significant technical challenges in measuring the film cooling effectiveness (η) of the serpentine nozzle using pressure-sensitive paint (PSP) technology in a confined curved space, and the complex pressure gradients make the cooling performance complicated. This study investigates the cooling performance of multi-row holes of a serpentine nozzle, experimentally and numerically. The results show that the cooling performance of the upstream region is better than that of the downstream region for a small relative mass flow ratio (MFRr), while the opposite is true for large MFRrs. The area-averaged film cooling effectiveness (η‾area) at MFRr = 0.75, 1.0, and 1.5 is 8.1 %, 2.9 %, and 1.6 % lower than that at MFRr = 1.25, respectively. The use of multi-row film holes with a staggered arrangement demonstrates clear advantages over inline arrangements, with the η‾area for staggered arrangements being 30.4 % higher than that for inline arrangements. A smaller inclination angle shows better film cooling performance, with the η‾area for inclination angles of 45° and 60° being 8.9 % and 20.5 % lower than that for an angle of 30°, respectively. Fan-shaped holes exhibit the highest η‾area at all MFRrs, while other diffuser-shaped holes only perform well at certain MFRrs. Cylindrical, laidback, and laidback fan-shaped holes exhibit η‾area values that are 12.2 %, 7.1 %, and 8.7 % lower than that of fan-shaped holes, respectively. Therefore, a staggered arrangement should be applied for the multi-row film hole design of a serpentine nozzle, in addition to using film holes with smaller inclination angles and a fan-shaped exit.
AB - There are significant technical challenges in measuring the film cooling effectiveness (η) of the serpentine nozzle using pressure-sensitive paint (PSP) technology in a confined curved space, and the complex pressure gradients make the cooling performance complicated. This study investigates the cooling performance of multi-row holes of a serpentine nozzle, experimentally and numerically. The results show that the cooling performance of the upstream region is better than that of the downstream region for a small relative mass flow ratio (MFRr), while the opposite is true for large MFRrs. The area-averaged film cooling effectiveness (η‾area) at MFRr = 0.75, 1.0, and 1.5 is 8.1 %, 2.9 %, and 1.6 % lower than that at MFRr = 1.25, respectively. The use of multi-row film holes with a staggered arrangement demonstrates clear advantages over inline arrangements, with the η‾area for staggered arrangements being 30.4 % higher than that for inline arrangements. A smaller inclination angle shows better film cooling performance, with the η‾area for inclination angles of 45° and 60° being 8.9 % and 20.5 % lower than that for an angle of 30°, respectively. Fan-shaped holes exhibit the highest η‾area at all MFRrs, while other diffuser-shaped holes only perform well at certain MFRrs. Cylindrical, laidback, and laidback fan-shaped holes exhibit η‾area values that are 12.2 %, 7.1 %, and 8.7 % lower than that of fan-shaped holes, respectively. Therefore, a staggered arrangement should be applied for the multi-row film hole design of a serpentine nozzle, in addition to using film holes with smaller inclination angles and a fan-shaped exit.
KW - Diffuser-shaped holes
KW - Film cooling
KW - Inclination angle
KW - Multi-row film holes
KW - Pressure-sensitive paint
UR - http://www.scopus.com/inward/record.url?scp=85219023752&partnerID=8YFLogxK
U2 - 10.1016/j.energy.2025.135352
DO - 10.1016/j.energy.2025.135352
M3 - 文章
AN - SCOPUS:85219023752
SN - 0360-5442
VL - 320
JO - Energy
JF - Energy
M1 - 135352
ER -
