Effect of Unsteady Wake on Full Coverage Film-Cooling Effectiveness for A Gas Turbine Blade

2006 ◽  
Author(s):  
Shantanu Mhetras ◽  
Je-Chin Han
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Film Cooling ◽  
Gas Turbine Blade ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Full Coverage ◽  
Unsteady Wake

Unsteady Wake Effect on Film Temperature and Effectiveness Distributions for a Gas Turbine Blade

1999 ◽  
Vol 122 (2) ◽  
pp. 340-347 ◽  
Author(s):  
Shuye Teng ◽  
Dong Kee Sohn ◽  
Je-Chin Han
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Film Cooling ◽  
Suction Side ◽  
Boundary Layer Transition ◽  
Gas Turbine Blade ◽  
Wake Effect ◽  
Layer Transition ◽  
Film Cooling Effectiveness ◽  
Unsteady Wake

The film effectiveness and coolant jet temperature profile on the suction side of a gas turbine blade were measured using a transient liquid crystal and a cold-wire technique, respectively. The blade has only one row of film holes near the gill hole portion on the suction side of the blade. Tests were performed on a five-blade linear cascade in a low-speed wind tunnel. The mainstream Reynolds number based on cascade exit velocity was 5.3×105. Upstream unsteady wakes were simulated using a spoke-wheel type wake generator. Coolant blowing ratio was varied from 0.6 to 1.2. Wake Strouhal number was kept at 0 and 0.1. Results show that unsteady wake reduces film cooling effectiveness. Results also show that film injection enhances local heat transfer coefficient while the unsteady wake promotes earlier boundary-layer transition. The development of coolant jet temperature profiles could be used to explain the film cooling performance. [S0889-504X(00)00402-5]

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

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.

Increasing film cooling effectiveness of a gas turbine blade by using an upstream ramp

2018 ◽  
Author(s):  
Md Rysul Kabir ◽  
Md. Salman Rabbi Limon ◽  
Sumon Saha ◽  
Mohammad Nasim Hasan
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Film Cooling ◽  
Gas Turbine Blade ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness

scholarly journals Experimental and Numerical Investigation of Effect of Blowing Ratio on Film Cooling Effectiveness and Heat Transfer Coefficient Over a Gas Turbine Blade Leading Edge Film Cooling Configurations

2013 ◽  
Author(s):  
Yepuri Giridhara Babu ◽  
Gururaj Lalgi ◽  
Ashok Babu Talanki Puttarangasetty ◽  
Jesuraj Felix ◽  
Sreenivas Rao V. Kenkere ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Film Cooling ◽  
Gas Turbine Blade ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Blowing Ratio

Film cooling is one of the cooling techniques to cool the hot section components of a gas turbine engines. The gas turbine blade leading edges are the vital parts in the turbines as they are directly hit by the hot gases, hence the optimized cooling of gas turbine blade surfaces is essential. This study aims at investigating the film cooling effectiveness and heat transfer coefficient experimentally and numerically for the three different gas turbine blade leading edge models each having the one row of film cooling holes at 15, 30 and 45 degrees hole orientation angle respectively from stagnation line. Each row has the five holes with the hole diameter of 3mm, pitch of 20mm and has the hole inclination angle of 20deg. in spanwise direction. Experiments are carried out using the subsonic cascade tunnel facility of National Aerospace Laboratories, Bangalore at a nominal flow Reynolds number of 1,00,000 based on the leading edge diameter, varying the blowing ratios of 1.2, 1.50, 1.75 and 2.0. In addition, an attempt has been made for the film cooling effectiveness using CFD simulation, using k-€ realizable turbulence model to solve the flow field. Among the considered 15, 30 and 45 deg. models, both the cooling effectiveness and heat transfer coefficient shown the increase with the increase in hole orientation angle from stagnation line. The film cooling effectiveness increases with the increase in blowing ratio upto 1.5 for the 15 and 30 deg. models, whereas on the 45 deg. model the increase in effectiveness shown upto the blowing ratio of 1.75. The heat transfer coefficient values showed the increase with the increase in blowing ratio for all the considered three models. The CFD results in the form of temperature, velocity contours and film cooling effectiveness values have shown the meaningful results with the experimental values.

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