TY - GEN
T1 - Effect of density ratio on film-cooling effectiveness distribution & its uniformity for several hole geometries on a flat plate
AU - Yao, Jiaxu
AU - Xu, Jin
AU - Zhang, Ke
AU - Lei, Jiang
AU - Wright, Lesley M.
N1 - Publisher Copyright:
Copyright © 2017 ASME.
PY - 2017
Y1 - 2017
N2 - Film cooling effectiveness distribution and its uniformity downstream of a row of film cooling holes on a flat plate are investigated by Pressure Sensitive Paint (PSP) under different density ratios. Several hole geometries are studied, including a streamwise cylindrical hole, a compound-Angled cylindrical hole, a streamwise fan-shape hole, a compound-Angled fanshape hole, and double-jet film-cooling (DJFC) holes. All of them have an inclination angle (θ) of 35°.The compound angle (β) is 45°. The fan-shape hole has a 10° expansion in the spanwise direction. In order to have a fair comparison, the pitches are kept as 4d for the cylindrical and the fan-shape holes, and 8d for the double-jet film-cooling holes. The investigated uniformity of effectiveness distribution is described by a new parameter (Lateral-Uniformity, LU) defined in this paper. Effects of density ratios (DR=1.0, 1.5 and 2.5) on film-cooling effectiveness and its uniformity are focused. Differences among geometries and effects of blowing ratios (M=0.5, 1.0, 1.5, and 2.0) are also considered. Results show that at higher density ratios, the lateral spread for discrete-hole geometries (i.e., the cylindrical and the fan-shape holes) is enhanced, and the DJFC holes is more advantageous, and the high effectiveness region near the downstream hole exit is larger. Mostly, increased lateral-uniformity is obtained at DR=2.5 due to better coolant coverage and enhanced lateral spread, but the effects of density ratios on lateral-uniformity are not monotonic in some cases. Utilizing compound angle configuration leads to increased lateral-uniformity due to stronger spanwise motion of the jet. Generally, with higher blowing ratio, the lateral-uniformity for the discrete-hole geometries decreases due to narrower traces, while it for the DJFC holes increases due to stronger spanwise movement. Keywords: Double-Jet Film-Cooling (DJFC); Density ratios; Film-Cooling Effectiveness; Uniformity.
AB - Film cooling effectiveness distribution and its uniformity downstream of a row of film cooling holes on a flat plate are investigated by Pressure Sensitive Paint (PSP) under different density ratios. Several hole geometries are studied, including a streamwise cylindrical hole, a compound-Angled cylindrical hole, a streamwise fan-shape hole, a compound-Angled fanshape hole, and double-jet film-cooling (DJFC) holes. All of them have an inclination angle (θ) of 35°.The compound angle (β) is 45°. The fan-shape hole has a 10° expansion in the spanwise direction. In order to have a fair comparison, the pitches are kept as 4d for the cylindrical and the fan-shape holes, and 8d for the double-jet film-cooling holes. The investigated uniformity of effectiveness distribution is described by a new parameter (Lateral-Uniformity, LU) defined in this paper. Effects of density ratios (DR=1.0, 1.5 and 2.5) on film-cooling effectiveness and its uniformity are focused. Differences among geometries and effects of blowing ratios (M=0.5, 1.0, 1.5, and 2.0) are also considered. Results show that at higher density ratios, the lateral spread for discrete-hole geometries (i.e., the cylindrical and the fan-shape holes) is enhanced, and the DJFC holes is more advantageous, and the high effectiveness region near the downstream hole exit is larger. Mostly, increased lateral-uniformity is obtained at DR=2.5 due to better coolant coverage and enhanced lateral spread, but the effects of density ratios on lateral-uniformity are not monotonic in some cases. Utilizing compound angle configuration leads to increased lateral-uniformity due to stronger spanwise motion of the jet. Generally, with higher blowing ratio, the lateral-uniformity for the discrete-hole geometries decreases due to narrower traces, while it for the DJFC holes increases due to stronger spanwise movement. Keywords: Double-Jet Film-Cooling (DJFC); Density ratios; Film-Cooling Effectiveness; Uniformity.
KW - Density ratios
KW - Double-jet film-cooling (DJFC)
KW - Film-cooling effectiveness
KW - Uniformity
UR - https://www.scopus.com/pages/publications/85029037899
U2 - 10.1115/GT2017-63743
DO - 10.1115/GT2017-63743
M3 - 会议稿件
AN - SCOPUS:85029037899
T3 - Proceedings of the ASME Turbo Expo
BT - Heat Transfer
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition, GT 2017
Y2 - 26 June 2017 through 30 June 2017
ER -