Experimental Study on Film Cooling Effectiveness of Blade With Chevron Shaped Holes Under Wake Influence

2021 ◽  
Author(s):  
Jichen Li ◽  
Huiren Zhu ◽  
Dawei Chen ◽  
Daoen Zhou
Keyword(s):  
Experimental Study ◽  
Film Cooling ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness

scholarly journals Experimental Study Of Short Hole Film-Cooling

2021 ◽  
Author(s):  
Mohammed A. Gandhi
Keyword(s):  
Experimental Study ◽  
Wind Tunnel ◽  
Film Cooling ◽  
Double Row ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Single Row ◽  
Blowing Ratio ◽  
Lift Off ◽  
Low Speed Wind Tunnel

An experimental study was conducted to investigate the film cooling effectiveness of a few configurations of short injection holes: single row, double row and both of the preceding cases with an upstream ramp placed at two different locations. In order to perform the above study, a wind-tunnel facility was assembled to facilitate in the successful culmination of the experiments. The focus of the study was to determine the cooling provided by the short injection holes at a variety of blowing ratios and whether adding an extra row of holes, upstream of the first row would make a difference. For the second part, a ramp was placed upstream of the single and double row configuration to help improve cooling . All of the experiments were performed in a low speed wind-tunnel with a mainstream velocity of 8 m/s and a turbulence insity of 3.3%. Higher blowing ratios were ineffective in improving film-cooling effectiveness due to jet lift-off. Two rows of holes increased the cooling effectiveness by 200%, when compared to single row configurations at the same blowing ratio without ramps. Upstream ramps provided significant improvement in the near hole region of the injection holes.

scholarly journals Experimental Study Of Short Hole Film-Cooling

2021 ◽  
Author(s):  
Mohammed A. Gandhi
Keyword(s):  
Experimental Study ◽  
Wind Tunnel ◽  
Film Cooling ◽  
Double Row ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Single Row ◽  
Blowing Ratio ◽  
Lift Off ◽  
Low Speed Wind Tunnel

An experimental study was conducted to investigate the film cooling effectiveness of a few configurations of short injection holes: single row, double row and both of the preceding cases with an upstream ramp placed at two different locations. In order to perform the above study, a wind-tunnel facility was assembled to facilitate in the successful culmination of the experiments. The focus of the study was to determine the cooling provided by the short injection holes at a variety of blowing ratios and whether adding an extra row of holes, upstream of the first row would make a difference. For the second part, a ramp was placed upstream of the single and double row configuration to help improve cooling . All of the experiments were performed in a low speed wind-tunnel with a mainstream velocity of 8 m/s and a turbulence insity of 3.3%. Higher blowing ratios were ineffective in improving film-cooling effectiveness due to jet lift-off. Two rows of holes increased the cooling effectiveness by 200%, when compared to single row configurations at the same blowing ratio without ramps. Upstream ramps provided significant improvement in the near hole region of the injection holes.

Experimental Study of Oscillating Freestream Effect on the Spatiotemporal Distributions of Leading-Edge Film Cooling

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Hongyi Shao ◽  
Mohamed Qenawy ◽  
Tianlun Zhang ◽  
Di Peng ◽  
Yingzheng Liu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Strouhal Number ◽  
Film Cooling ◽  
Turbine Blades ◽  
Leading Edge ◽  
Fast Response ◽  
Frame Rate ◽  
Cooling Effectiveness ◽  
Oscillation Effect ◽  
Film Cooling Effectiveness

Abstract An experimental study was conducted to investigate the influence of mainstream oscillations on spatio-temporal variation of leading-edge film cooling effectiveness. The investigation utilized fast-response pressure-sensitive paint (Fast-PSP) technique at high frame rate. During the experiment, coolant (i.e., CO2, DR = 1.53) was discharged into three rows of cylindrical holes. Various blowing ratios (i.e., M = 0.50, 0.75, 1.00, and 1.50) were tested under the steady (i.e., f = 0 Hz) and oscillating (i.e., f = 7 Hz and 25 Hz) conditions. The measured instantaneous effectiveness was analyzed in terms of time-averaged and phase-averaged results. The results revealed that the mainstream oscillation, consisting of simultaneous pressure and velocity oscillation, significantly influences the behavior of the film cooling effectiveness. The time-averaged effectiveness significantly decreased at high oscillating frequency (i.e., 13.0–19.8% reduction at M = 0.50, f = 25 Hz compared with f = 0 Hz), especially at low blowing ratios (i.e., M = 0.50 and 0.75). The phase-averaged results captured significant decay in the film distributions associated with backflow caused by negative pressure gradients in coolant holes at certain phases. However, the mainstream oscillation effect was relatively insignificant at high blowing ratios (i.e., M = 1.00 and 1.50), which revealed the robustness of coolant coverage at low coolant Strouhal number (i.e., high blowing ratio) under the same oscillating frequency. Furthermore, the unsteady coolant intermittency showed highly unstable film coverage at high coolant Strouhal number. The coolant decay associated with backflow at high coolant Strouhal number should be considered by the gas-turbine designers in order to improve the lifecycle of turbine blades.

scholarly journals Experimental study of the effect of a transverse trench depth on film cooling effectiveness

2021 ◽  
Vol 25 ◽  
pp. 100934
Author(s):  
I.A. Chokhar ◽  
A.Y. Dyachenko ◽  
M.A. Pakhomov ◽  
M.V. Philippov ◽  
V.I. Terekhov
Keyword(s):  
Experimental Study ◽  
Film Cooling ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness
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