scholarly journals Discussion: “The Role of Laminar-Turbulent Transition in Gas Turbine Engines: A Discussion” (Walker, G. J., 1993, ASME J. Turbomach., 115, pp. 207–216)

1993 ◽  
Vol 115 (2) ◽  
pp. 216-217
Author(s):  
N. A. Cumpsty
Keyword(s):  
Gas Turbine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Turbulent Transition ◽  
Laminar Turbulent Transition

The Role of Laminar-Turbulent Transition in Gas Turbine Engines

1991 ◽  
Author(s):  
Robert Edward Mayle
Keyword(s):  
Gas Turbine ◽  
Transitional Flow ◽  
Turbine Engines ◽  
Future Research ◽  
Critical Study ◽  
Gas Turbine Engines ◽  
Turbulent Transition ◽  
Engine Design ◽  
The Impact ◽  
Laminar Turbulent Transition

A critical study of laminar-turbulent transition phenomena and its role in aerodynamics and heat transfer in modern and future gas turbine engines is presented. In order to develop a coherent view of the subject, a current look at transition phenomena from both a theoretical and experimental standpoint are provided and a comprehensive state-of-the-art account of transitional phenomena in the engine’s throughflow components given. The impact of transitional flow on engine design is discussed and suggestions for future research and developmental work provided.

The 1991 IGTI Scholar Lecture: The Role of Laminar-Turbulent Transition in Gas Turbine Engines

1991 ◽  
Vol 113 (4) ◽  
pp. 509-536 ◽  
Author(s):  
Robert Edward Mayle
Keyword(s):  
Gas Turbine ◽  
Transitional Flow ◽  
Turbine Engines ◽  
Future Research ◽  
Critical Study ◽  
Gas Turbine Engines ◽  
Turbulent Transition ◽  
Engine Design ◽  
The Impact ◽  
Laminar Turbulent Transition

A critical study of laminar-turbulent transition phenomena and their role in aerodynamics and heat transfer in modern and future gas turbine engines is presented. In order to develop a coherent view of the subject, a current look at transition phenomena from both a theoretical and experimental standpoint are provided and a comprehensive state-of-the-art account of transitional phenomena in the engine’s throughflow components given. The impact of transitional flow on engine design is discussed and suggestions for future research and developmental work provided.

A Diagnostic Expert System for Oil Systems of Aeroengines

1993 ◽  
Author(s):  
Hong Cao ◽  
Mei Ma
Keyword(s):  
Artificial Intelligence ◽  
Expert System ◽  
Gas Turbine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Complex Relation

DIAG, a diagnostic expert system for oil systems of aeroengines, is presented in this paper. Using artificial intelligence, DIAG, which simulates the role of human experts in solving problems, can solve the complicated problems in diagnosing the faults and failures of oil systems of gas turbine engines. The paper concentrates on the design of DIAG as well as the process of handling the complex relation and uncertainty of problems. It also includes graphic subsystem and data subsystem. It is affirmed by the expected goal of diagnosing the faults and failures of oil system and engine of CFM56 engine on Boeing 737–300 airplane.

Relight Envelope of a Military Gas Turbine Engine: An Experimental Study

2008 ◽  
Author(s):  
R. K. Mishra ◽  
G. Gouda ◽  
B. S. Vedaprakash
Keyword(s):  
Gas Turbine ◽  
Fuel Injection ◽  
Full Scale ◽  
Test Facility ◽  
Turbine Engines ◽  
Engine Fuel ◽  
Gas Turbine Engines ◽  
Turbine Engine ◽  
Start Up

A twin spool low bypass turbofan engine under development and its combustor in full-scale were tested independently at altitude conditions to establish the relight envelope of the engine. Demonstration of relight capability and defining its boundary are mandatory for military gas turbine engines and for single engine application in particular. The engine was first subjected to windmill to establish its windmilling characteristics. The full engine was then tested for light-off in an altitude test facility simulating windmilling conditions from 4 to 12 km altitude with flight Mach numbers from 0.2 to 1.0. The relight boundary is defined based on the successful light-off points achieved from engine tests. Similar tests were carried out on the full-scale combustion chamber in a stand-alone mode simulating altitude conditions at engine flame-out. The combustor test has defined the light-off and lean blow out limits of the at each point on the relight boundary. The information of fuel-air ratio at light-off and blow-out is very useful in setting the engine fuel schedule for altitude operation and relight. In this paper an attempt is made to highlight various tests carried out on engine and its combustor to define the relight boundary of the engine. The paper also emphasizes the experience of combustor development and associated problems in meeting the relight challenges of military engines. These problems include the necessity of higher fuel-air ratio at high altitudes, the role of additional localized fuel injection through start-up atomizers, and effect of single igniter on relight characteristics. The relight envelope demonstrated by the engine is very satisfactory to meet the first flight requirement where the flight mission generally concentrate in the zone of 0.6 to 0.8 Mach and altitude does not exceed 10 to 12 km. Combustor and atomizer modification is needed to improve relight performance and to shift the boundary to further left.

The Role of Laminar-Turbulent Transition in Gas Turbine Engines: A Discussion

1993 ◽  
Vol 115 (2) ◽  
pp. 207-216 ◽  
Author(s):  
G. J. Walker
Keyword(s):  
Pressure Gradient ◽  
Gas Turbine ◽  
Free Stream ◽  
Turbine Engines ◽  
Critical Study ◽  
Gas Turbine Engines ◽  
Laminar Separation ◽  
Free Stream Turbulence ◽  
Turbulent Transition ◽  
Transition Length

An extended discussion of Mayle’s (1991) critical study of transition phenomena in gas turbine engines is presented. Attention is focused on transition in decelerating flow regions, which are the major sources of loss production for axial turbomachine blades. The following points are examined in detail: (a) the physics of transition and its implications for the correlation of various transition phenomena; (b) the relative importance of pressure gradient and free-stream turbulence in controlling transition; (c) the influence of pressure gradient on periodic-unsteady transition; (d) the correlation of transition length under conditions of arbitrary pressure gradient and free-stream turbulence level; and (e) transition behavior in laminar separation bubbles. The discussion examines various differences in philosophy concerning the above phenomena and makes further suggestions for transition research, which may assist in resolving the issues raised.

scholarly journals The Role of Laminar-Turbulent Transition in Gas Turbine Engines: A Discussion

1992 ◽  
Author(s):  
G. J. Walker
Keyword(s):  
Pressure Gradient ◽  
Gas Turbine ◽  
Free Stream ◽  
Turbine Engines ◽  
Critical Study ◽  
Gas Turbine Engines ◽  
Laminar Separation ◽  
Free Stream Turbulence ◽  
Turbulent Transition ◽  
Transition Length

An extended discussion of Mayle’s (1991) critical study of transition phenomena in gas turbine engines is presented. Attention is focussed on transition in decelerating flow regions which are the major sources of loss production for axial turbomachine blades. The following points are examined in detail: (a) the physics of transition and its implications for the correlation of various transition phenomena; (b) the relative importance of pressure gradient and free-stream turbulence in controlling transition; (c) the influence of pressure gradient on periodic-unsteady transition; (d) the correlation of transition length under conditions of arbitrary pressure gradient and free-stream turbulence level; and (e) transition behavior in laminar separation bubbles. The discussion examines various differences in philosophy concerning the above phenomena and corrects some areas of misinterpretation in the subject review paper. It concludes with further suggestions for transition research which may assist in resolving the issues raised.

scholarly journals Deposition: Hot Corrosion in Gas Turbine Engines

1981 ◽  
Author(s):  
N. S. Bornstein ◽  
M. A. DeCrescente
Keyword(s):  
Gas Turbine ◽  
Protective Coatings ◽  
Salt Water ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Accelerated Corrosion ◽  
Surface Stability ◽  
Salt Crystals ◽  
Oxidation And Corrosion

The superalloys employed in industrial marine and aircraft gas turbine engines are among the strongest and most oxidation resistant structural materials known. Moreover, it is common practice to further increase the surface stability of hot turbine components by the use of protective coatings. Nevertheless accelerated oxidation and corrosion occurs and can limit the use life of gas turbine components. The principal constituents of the deposits that accumulate on turbine components that are associated with accelerated corrosion are alkali salts. The source of the alkali constituents are generally believed to be sea salt crystals, which can travel hundreds of miles with the prevailing winds, or salt water contamination of otherwise clean fuels. The objective of the studies reported herein is to relate the modes of deposition of salts with corrosion and investigate the role of char as it affects corrosion so that the appropriate steps can be taken to increase gas turbine life.

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