The Impact of Blade-to-Blade Flow Variability on Turbine Blade Cooling Performance

2004 ◽  
Author(s):  
David Darmofal ◽  
Vince Sidwell
Keyword(s):  
Turbine Blade ◽  
Cooling Performance ◽  
Flow Variability ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
The Impact

The Impact of Blade-to-Blade Flow Variability on Turbine Blade Cooling Performance

2005 ◽  
Vol 127 (4) ◽  
pp. 763-770 ◽  
Author(s):  
Vince Sidwell ◽  
David Darmofal
Keyword(s):  
Turbine Blade ◽  
High Flow ◽  
Low Flow ◽  
Simplified Model ◽  
Selective Assembly ◽  
Turbine Blade Cooling ◽  
Cooling Flow ◽  
Blade Cooling ◽  
Blade Row ◽  
The Impact

The focus of this paper is the impact of manufacturing variability on turbine blade cooling flow and, subsequently, its impact on oxidation life. A simplified flow network model of the cooling air supply system and a row of blades is proposed. Using this simplified model, the controlling parameters which affect the distribution of cooling flow in a blade row are identified. Small changes in the blade flow tolerances (prior to assembly of the blades into a row) are shown to have a significant impact on the minimum flow observed in a row of blades resulting in substantial increases in the life of a blade row. A selective assembly method is described in which blades are classified into a low-flow and a high-flow group based on passage flow capability (effective areas) in life-limiting regions and assembled into rows from within the groups. Since assembling rows from only high-flow blades is equivalent to raising the low-flow tolerance limit, high-flow blade rows will have the same improvements in minimum flow and life that would result from more stringent tolerances. Furthermore, low-flow blade rows are shown to have minimum blade flows which are the same or somewhat better than a low-flow blade that is isolated in a row of otherwise higher-flowing blades. As a result, low-flow blade rows are shown to have lives that are no worse than random assembly from the full population. Using a higher fidelity model for the auxiliary air system of an existing jet engine, the impact of selective assembly on minimum blade flow and life of a row is estimated and shown to be in qualitative and quantitative agreement with the simplified model analysis.

scholarly journals A Comparison Between Engine Test Results and Design Predictions of Turbine Blade Cooling Performance

1989 ◽  
Author(s):  
J. M. Hannis ◽  
M. K. D. Smith
Keyword(s):  
Turbine Blade ◽  
Turbine Blades ◽  
Research Work ◽  
Engine Test ◽  
Test Results ◽  
Supportive Evidence ◽  
Cooling Performance ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Design Calculations

Significant differences exist between the behaviour of cooled turbine blades under engine conditions and their behaviour as predicted in design calculations. This paper presents a comparison between engine test data, static cascade rig data, and design predictions. Wherever possible, the reasons for the differences are identified and cross referenced to recently reported research work. In some cases hard supportive evidence for phenomena observed on research rigs has been obtained from engine tests. The data is presented for two subsonic aerofoil designs with several different cooling configurations.

Exploring the Impact of Elevated Turbine Blade Cooling Effectiveness and Turbine Material Temperatures on Gas Turbine Engine Performance and Cost

2015 ◽  
Author(s):  
Aaron R. Byerley ◽  
August J. Rolling
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Turbine Blade ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Cooling Effectiveness ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Turbine Inlet ◽  
The Impact

Since the 1950’s, the turbine inlet temperatures of gas turbine engines have been steadily increasing as engine designers have sought to increase engine thrust-to-weight and reduce fuel consumption. In turbojets and low-bypass turbofan engines, increasing the turbine inlet temperature boosts specific thrust, which in some cases can support supersonic flight without the use of an afterburner. In high-bypass gas turbine engines, increasing the turbine inlet temperature makes possible higher bypass ratios and overall pressure ratios, both of which reduce specific fuel consumption. Increased turbine inlet temperatures, without sacrificing blade life, have been made possible through advances in blade cooling effectiveness and high-temperature turbine blade materials. Investigating the impact of higher turbine inlet temperatures and the corresponding cooling air flow rates on specific thrust, specific fuel consumption, and engine development cost is the subject of this paper. A physics-based cooling effectiveness correlation is presented for linking turbine inlet temperature to cooling flow fraction. Two cases are considered: 1) a low-bypass, mixed-exhaust, non-afterburning turbofan engine intended to support supercruising at Mach 1.5 and 2) a high-bypass, unmixed-exhaust turbofan engine intended to support highly efficient, long range flight at Mach 0.8. For each of these two cases, both baseline and enhanced cooling effectiveness values as well as both baseline and elevated turbine blade material temperatures are considered. Comparing these cases will ensure that students taking courses in preliminary engine design understand why huge research investments continue to be made in turbine blade cooling and advanced, high-temperature turbine blade material development.

TURBINE BLADE COOLING AT BUAA

2018 ◽  
Author(s):  
Zhi Tao ◽  
Haiwang Li ◽  
Ruquan You
Keyword(s):  
Turbine Blade ◽  
Turbine Blade Cooling ◽  
Blade Cooling

Flow in a Simulated Turbine Blade Cooling Channel With Spatially Varying Roughness Caused by Additive Manufacturing Orientation

2020 ◽  
Author(s):  
Stephen T. McClain ◽  
David R. Hanson ◽  
Emily Cinnamon ◽  
Jacob C. Snyder ◽  
Robert F. Kunz ◽  
...  
Keyword(s):  
Turbine Blade ◽  
Inconel 718 ◽  
Rough Surfaces ◽  
Structured Light ◽  
Internal Flow ◽  
Smooth Wall ◽  
Number Range ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Hot Film

Abstract Because of the effects of gravity acting on the melt region created during the laser sintering process, additively manufactured surfaces that are pointed upward have been shown to exhibit roughness characteristics different from those seen on surfaces that point downward. For this investigation, the Roughness Internal Flow Tunnel (RIFT) and computational fluid dynamics models were used to investigate flow in channels with different roughness on opposing walls of the channel. Three rough surfaces were employed for the investigation. Two of the surfaces were created using scaled, structured-light scans of the upskin and downskin surfaces of an Inconel 718 component which was created at a 45° angle to the printing surface and documented by Snyder et al. [1]. A third rough surface was created for the RIFT investigation using a structured-light scan of a surface similar to the Inconel 718 downskin surface, but a different scaling was used to provide larger roughness elements in the RIFT. The resulting roughness dimensions (Rq/Dh) of the three surfaces used were 0.0064, 0.0156, and 0.0405. The friction coefficients were measured over the range of 10,000 < ReDh < 70,000 for each surface opposed by a smooth wall and opposed by each of the other rough walls. At multiple ReDh values, x-array hot film anemometry was used to characterize the velocity and turbulence profiles for each roughness combination. The friction factor variations for each rough wall opposed by a smooth wall approached complete turbulence. However, when rough surfaces were opposed, the surfaces did not reach complete turbulence over the Reynolds number range investigated. The results of inner variable analysis demonstrate that the roughness function (ΔU+) becomes independent of the roughness condition of the opposing wall providing evidence that Townsend’s Hypothesis holds for the relative roughness values expected for additively manufactured turbine-blade cooling passages.

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