On Improving Full-Coverage Effusion Cooling Efficiency by Varying Cooling Arrangements and Wall Thickness in Double Wall Cooling Application

2018 ◽  
Author(s):  
Weihong Li ◽  
Xunfeng Lu ◽  
Xueying Li ◽  
Jing Ren ◽  
Hongde Jiang
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Wall Thickness ◽  
Film Cooling ◽  
Density Ratio ◽  
Cooling Efficiency ◽  
Gas Turbine Blade ◽  
Cooling Effectiveness ◽  
Full Coverage ◽  
Double Wall

Overall cooling effectiveness was determined for a full-coverage effusion cooled surface which simulated a portion of a double wall cooling gas turbine blade. The overall cooling effectiveness was measured with high thermal-conductivity artificial marble using infra-red thermography. The Biot number of artificial marble was matched to real gas turbine blade conditions. Blowing ratio ranged from 0.5 to 2.5 with the density ratio of DR = 1.5. A variation of cooling arrangements, including impingement-only, film cooling-only, film cooling with impingement and film cooling with impingement and pins, as well as forward/backward film injection, were employed to provide a systematic understanding on their contribution to improve cooling efficiency. Also investigated was the effect of reducing wall thickness. Local, laterally-averaged, and area-averaged overall cooling effectiveness were shown to illustrate the effects of cooling arrangements and wall thickness. Results showed that adding impingement and pins to film cooling, and decreasing wall thickness increase the cooling efficiency significantly. Also observed was that adopting backward injection for thin full-coverage effusion plate improves the cooling efficiency.

On Improving Full-Coverage Effusion Cooling Efficiency by Varying Cooling Arrangements and Wall Thickness in Double Wall Cooling Application

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Weihong Li ◽  
Xunfeng Lu ◽  
Xueying Li ◽  
Jing Ren ◽  
Hongde Jiang
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Wall Thickness ◽  
Film Cooling ◽  
Density Ratio ◽  
Cooling Efficiency ◽  
Gas Turbine Blade ◽  
Cooling Effectiveness ◽  
Full Coverage ◽  
Double Wall

Overall cooling effectiveness was determined for a full-coverage effusion cooled surface which simulated a portion of a double wall cooling gas turbine blade. The overall cooling effectiveness was measured with high thermal-conductivity artificial marble using infrared thermography. The Biot number of artificial marble was matched to real gas turbine blade conditions. Blowing ratio ranged from 0.5 to 2.5 with the density ratio of DR = 1.5. A variation of cooling arrangements, including impingement-only, film cooling-only, film cooling with impingement, and film cooling with impingement and pins, as well as forward/backward film injection, was employed to provide a systematic understanding on their contribution to improve cooling efficiency. Also investigated was the effect of reducing wall thickness. Local, laterally averaged, and area-averaged overall cooling effectiveness were shown to illustrate the effects of cooling arrangements and wall thickness. Results showed that adding impingement and pins to film cooling, and decreasing wall thickness increase the cooling efficiency significantly. Also observed was that adopting backward injection for thin full-coverage effusion plate improves the cooling efficiency.

Film-Cooling Effectiveness on Squealer Cavity and Rim Walls of Gas-Turbine Blade Tip

2006 ◽  
Vol 22 (4) ◽  
pp. 898-899 ◽  
Author(s):  
Shantanu Mhetras ◽  
Huitao Yang ◽  
Zhihong Gao ◽  
Je-Chin Han
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Film Cooling ◽  
Gas Turbine Blade ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Blade Tip

Effects of a Groove Patterned Cooling Tube on the Film Cooling Performance of a Gas Turbine Blade

2017 ◽  
Author(s):  
Yeon-Ho Lee ◽  
Youn-Jea Kim
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Film Cooling ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Cooling Efficiency ◽  
Gas Turbine Blade ◽  
Cooling Performance ◽  
Cooling Tube ◽  
Film Cooling Efficiency

A high working fluid temperature in a gas turbine is required to improve its efficiency. However, high temperatures also reduce turbine blade durability. Film-cooling is one blade cooling method to control gas turbine blade temperature. In this study, film cooling performance was numerically investigated with various configurations of a groove patterned cooling tube. The CO2 blowing ratio of the cooling fluid was varied from 0.6 to 1.4 with 0.2 intervals. The numerical analysis was conducted using the ANSYS CFX ver. 16.1 commercial code. The film cooling efficiency and pressure distribution were graphically depicted and analyzed to derive the groove configuration with the highest film cooling efficiency. In particular, the flow field on the turbine blade with the circular groove configuration showed more uniform distribution compared to the reference model.

Parametric Study of Showerhead Film Cooling Performance on a Gas Turbine Blade

2014 ◽  
Author(s):  
G. Urquiza ◽  
J. O. Davalos ◽  
J. C. Garcia ◽  
L. Castro ◽  
J. A. Rodríguez ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Film Cooling ◽  
Operating Conditions ◽  
Geometrical Parameters ◽  
Blade Surface ◽  
Gas Turbine Blade ◽  
Gas Temperature ◽  
Cooling Effectiveness ◽  
Blade Geometry

Gas turbine power and efficiency have direct relation with inlet gas temperature. However, high gas temperature could cause thermal damage to gas turbine blade material. Gas turbine blade could be cooled using the so-called film cooling technique which is necessary to ensure blade material integrity. In film cooling, air from compressor is injected through internal blade ducts. The air leaves the internal ducts through holes placed on blade surface, creating a cooling film on the blade surface. Operating conditions and hole geometrical factors can influence the cooling effectiveness. Several investigations have been conducted related to film cooling in order to study its behavior under different conditions. Due to its complexity, many studies replace blade geometry for flat plates. A better approximation to realistic results could be obtained by modeling the blade geometry with cooling holes. In this work, influence of geometrical parameters on cooling effectiveness under different operating conditions, like blowing ratio and angular velocity, is studied by means of numerical analysis using a commercial CFD code. The object of study is a typical showerhead configuration at mid-span of the tested blade, with three rows of cooling holes. In order to reduce computational cost, an algorithm was implemented to generate blade geometries and grids, performing numerical analyses and computing results in an automatic way, based on selected parameters. The algorithm could be used in optimization process to reduce the effort used in the construction geometries. The results show the effects of change geometrical parameters on cooling effectiveness. Additionally, changes on cooling flow direction are observed at high angular velocities.

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