scholarly journals The Role of Stress–Strain State of Gas Turbine Engine Metal Parts in Predicting Their Safe Life

2021 ◽  
Vol 22 (4) ◽  
pp. 643-677
Author(s):  
Z. A. Duriagina ◽  
V. V. Kulyk ◽  
O. S. Filimonov ◽  
A. M. Trostianchyn ◽  
N. B. Sokulska
Keyword(s):  
Gas Turbine ◽  
Vapour Deposition ◽  
Material Selection ◽  
Low Cycle Fatigue ◽  
Turbine Blades ◽  
Chemical Vapour ◽  
Gas Turbine Engine ◽  
Fretting Wear ◽  
Turbine Engine ◽  
Metal Parts

The influence of various factors on the workability of critical metallic parts of a gas turbine engine (GTE) is analysed and systematized. As shown, compressor blades fail as a result of foreign-objects’ damage, gas corrosion, and erosion. Compressor blade roots in most cases fail due to fretting wear caused by vibrations, while the fir-tree rim of turbine discs fails due to low-cycle fatigue (LCF) damage and creep. An increase in the radial gaps between the rotor and stator of the turbine reduces the thrust force and causes changes in the gas-dynamic loading of the engine components. Additional oxidation of metal parts is observed under the action of hot gases from the combustion chamber. The principles of material selection for manufacturing turbine blades and disks, concepts of alloying heat-resistant alloys, and modern methods of surface engineering due to applying protective oxidation-resistant coatings, in particular, chemical vapour deposition (CDV), physical vapour deposition (PVD), air plasma spraying (APS), etc., are also described. To predict the lifetime of turbine disks, it is proposed to use the modified Walker model and Miner’s rule. To specify the time before the failure of the metal blades of the turbine, it is proposed to use the finite element method. To monitor the working-surfaces’ deformations of the gas turbine engine, it is recommended to use optical-digital methods.

scholarly journals Comprehensive report on Materials for Gas Turbine Engine Components

2019 ◽  
Vol 9 (2S2) ◽  
pp. 155-158
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Thermal Stresses ◽  
Prolonged Exposure ◽  
Raw Materials ◽  
Turbine Blades ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Turbine Engine ◽  
Engine Component

In the past three decades, it is very challenging for the researchers to design and development a best gas turbine engine component. Engine component has to face different operating conditions at different working environments. Nickel based superalloys are the best material to design turbine components. Inconel 718, Inconel 617, Hastelloy, Monel and Udimet are the common material used for turbine components. Directional solidification is one of the conventional casting routes followed to develop turbine blades. It is also reported that the raw materials are heat treated / age hardened to enrich the desired properties of the material implementation. Accordingly they are highly susceptible to mechanical and thermal stresses while operating. The hot section of the turbine components will experience repeated thermal stress. The halides in the combination of sulfur, chlorides and vanadate are deposited as molten salt on the surface of the turbine blade. On prolonged exposure the surface of the turbine blade starts to peel as an oxide scale. Microscopic images are the supportive results to compare the surface morphology after complete oxidation / corrosion studies. The spectroscopic results are useful to identify the elemental analysis over oxides formed. The predominant oxides observed are NiO, Cr2O3, Fe2O3 and NiCr2O4. These oxides are vulnerable on prolonged exposure and according to PB ratio the passivation are very less. In recent research, the invention on nickel based superalloys turbine blades produced through other advanced manufacturing process is also compared. A summary was made through comparing the conventional material and advanced materials performance of turbine blade material for high temperature performance.

Modeling of Cyclic Life for Compressor Rotor of Gas Turbine Engine Taking Into Account Production Deviations

2020 ◽  
Author(s):  
Alexandr N. Arkhipov ◽  
Yury A. Ravikovich ◽  
Anton A. Matushkin ◽  
Dmitry P. Kholobtsev
Keyword(s):  
Gas Turbine ◽  
Low Cycle Fatigue ◽  
Probabilistic Modeling ◽  
Gas Turbine Engine ◽  
Critical Zone ◽  
Design Stage ◽  
Cyclic Life ◽  
Engine Operation ◽  
Turbine Engine ◽  
Compressor Rotor

Abstract The regional aircraft with a turbofan gas turbine engine, created in Russia, is successfully operated in the world market. Further increase of the life and reduction of the cost of the life cycle are necessary to ensure the competitive advantages of the engine. One of the units limiting the engine life is the compressor rotor. The cyclic life of the rotor depends on many factors: the stress-strain state in critical zones, the life of the material under low-cycle loading, the regime of engine operation, production deviations (within tolerances), etc. In order to verify the influence of geometry deviations, the calculations of the model with nominal dimensions and the model with the most unfavorable geometric dimensions (worst cases) have been carried out. The obtained influence coefficients for geometric and weight tolerances are then used for probabilistic modeling of stresses in the critical zone. Rotor speed and gas loads on the blades for different flight missions and engine wear are determined from the corresponding aerodynamic calculations taking into account the actual flight cycles (takeoff, reduction, reverse) and are also used for stress recalculations. The subsequent calculation of the rotor cyclic life and the resource assessment is carried out taking into account the spread of the material low-cycle fatigue by probabilistic modeling of the rotor geometry and weight loads. A preliminary assessment of the coefficients of tolerances influence on stress in the critical zone can be used to select the optimal (in terms of life) tolerances at the design stage. Taking into account the actual geometric and weight parameters can allow estimating the stress and expected life of each manufactured rotor.

Development of the Ceramic Gas Turbine Engine System (CGT301)

1999 ◽  
Author(s):  
Takeshi Sakida ◽  
Shinya Tanaka ◽  
Takao Mikami ◽  
Masashi Tatsuzawa ◽  
Tomoki Taoka
Keyword(s):  
Gas Turbine ◽  
Turbine Blades ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
The Future ◽  
Engine System ◽  
Primary Type ◽  
Three Phases

The CGT301 ceramic gas turbine has been developed under a contract from NEDO as a part of the New Sunshine Program of MITI since 1988 to 1998. The CGT301 is a recuperated, single-shaft ceramic gas turbine. Ceramic parts are used in the hot section of the engine, such as turbine blades, nozzle vanes, combustion liners and so on. As a primary feature of this turbine, the rotors are composed of ceramic blades inserted into metallic disks (“hybrid rotor”) for the future applicability to the large gas turbine. The R & D program consists of three phases, the model metal gas turbine, the primary type ceramic gas turbine and the pilot ceramic gas turbine. The pilot ceramic gas turbine showed etable operation at TIT of 1,350°C. This paper presents the progress in the development of the pilot ceramic gas turbine of CGT301.

Fabrication and Performance of a Pin Fin Micro Heat Exchanger

2004 ◽  
Vol 126 (3) ◽  
pp. 434-444 ◽  
Author(s):  
Christophe Marques ◽  
Kevin W. Kelly
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Heat Exchangers ◽  
Turbine Blades ◽  
High Heat ◽  
Gas Turbine Engine ◽  
High Heat Flux ◽  
Turbine Engine ◽  
Pin Fin ◽  
Micro Heat Exchanger

Nickel micro pin fin heat exchangers can be electroplated directly onto planar or non-planar metal surfaces using a derivative of the LIGA micromachining process. These heat exchangers offer the potential to more effectively control the temperature of surfaces in high heat flux applications. Of particular interest is the temperature control of gas turbine engine components. The components in the gas turbine engine that require efficient, improved cooling schemes include the gas turbine blades, the stator vanes, the turbine disk, and the combustor liner. Efficient heating of component surfaces may also be required (i.e., surfaces near the compressor inlet to prevent deicing). In all cases, correlations providing the Nusselt number and the friction factor are needed for such micro pin fin heat exchangers. Heat transfer and pressure loss experimental results are reported for a flat parallel plate pin fin micro heat exchanger with a staggered pin fin array, with height-to-diameter ratios of 1.0, with spacing-to-diameter ratios of 2.5 and for Reynolds numbers (based on the hydraulic diameter of the channel) from 4000 to 20,000. The results are compared to studies of larger scale, but geometrically similar, pin fin heat exchangers. To motivate further research, an analytic model is described which uses the empirical results from the pin fin heat exchanger experiments to predict a cooling effectiveness exceeding 0.82 in a gas turbine blade cooling application. As a final point, the feasibility of fabricating a relatively complex micro heat exchanger on a simple airfoil (a cylinder) is demonstrated.

Development of a Hydraulic Filter for Nozzle Actuation System of a Gas Turbine Engine

2012 ◽  
Author(s):  
B. Arul Jothi ◽  
A. M. Junaid Basha
Keyword(s):  
Gas Turbine ◽  
Material Selection ◽  
Extreme Temperature ◽  
Aircraft Engine ◽  
Gas Turbine Engine ◽  
International Standards ◽  
Turbine Engine ◽  
Actuation System ◽  
Performance Qualification ◽  
Stringent Performance

The Integrated Nozzle Actuating System (INAS) of a gas turbine engine is used to vary the exhaust nozzle area to achieve an optimum performance. The nozzle actuating system is operated by four actuators driven by an Integrated Hydraulic Power Pack (IHPP) connected to the Engine Gear Box (EGB). The quality of the oil operating the precision hydraulic actuators of the INAS should be maintained contamination free to achieve an optimum efficiency of the actuators. Hence a fine hydraulic filter is used in the IHPP circuit to maintain the cleanliness level of the hydraulic oil operating the actuators. The design and development of a hydraulic filter for an aircraft engine is a challenging task involving material selection, manufacturing process quality control and stringent performance qualification test schedule to follow the International standards. The present work describes the development of a 10 micron hydraulic filter operating at 30 bar pressure with a flow of 20 lpm designed according to the specifications of a typical aircraft gas turbine engine IHPP system. The filter has been qualified through all the tests prescribed by the International MIL-F-8815E standards. The tests like Multi-pass test, cold start test, Flow fatigue test, extreme temperature test, vibration test and bubble point test are described and the results are discussed.

Design and Analysis of a New Accessory Gearbox Housing for a Gas Turbine Engine

2011 ◽  
Author(s):  
Partha S. Das
Keyword(s):  
Gas Turbine ◽  
Low Cycle Fatigue ◽  
Minimum Weight ◽  
Cost Savings ◽  
Gas Turbine Engine ◽  
Cycle Fatigue ◽  
Element Analysis ◽  
Turbine Engine ◽  
Housing Design ◽  
Engine Mount

Accessory Gearbox (AGB) Housing is one of the most critical components of a gas turbine engine that lies between the core engine & the aircraft. The function of the AGB Housing is to provide support for the gear drive assembly that transfers power from the engine to the engine accessories and to the power takeoff drive for the aircraft accessories. The housing also functions as an oil tight container and passageway for lubrication. In addition, the AGB housing provides mount points to attach engine/aircraft support accessories, including the engine mount points to the aircraft. The complexity in predicting AGB housing behavior under the gear loading, engine loading and engine induced vibration is one of the main challenges of designing a new gearbox with minimum weight. To address these issues, the current paper presents for the first time the design-analysis of a new lightweight AGB housing for a turboshaft engine, based on the following three major requirements: i) gear bearing pads strength & stiffness capability, ii) AGB mount pads (for accessories and for engine) load carrying capability, and, iii) vibratory response (mainly high cycle fatigue (HCF) response) of the AGB housing. A 3-D Finite Element Analysis (FEA) model of the AGB housing was developed using the proposed initial design. Various design modifications, involving several interrelated, iterative steps, were then carried out by adjusting and modifying the housing wall thickness, placement & sizes of internal ribs and external gussets, including additional geometric modifications to satisfy the design objectives. The result is a robust, lightweight AGB housing design, eliminating the need for some of the required testing for the qualification of the new gearbox, indicating a significant cost savings. This paper also discusses in detail the methodology for the gear bearing pad strength/stiffness calculation, the FEA modeling techniques for the application of mount loads and gear bearing loads under operating & flight maneuver conditions, and, a methodology for addressing a combined HCF & LCF (Low Cycle Fatigue) response of the housing.

Low Cycle Fatigue Counter

1980 ◽  
Vol 52 (6) ◽  
pp. 21-22
Keyword(s):  
Gas Turbine ◽  
High Speed ◽  
Low Cycle Fatigue ◽  
Engine Performance ◽  
Gas Turbine Engine ◽  
Rotating Machinery ◽  
Cycle Fatigue ◽  
Turbine Engine ◽  
On Demand ◽  
Long Life

The modern aircraft gas turbine engine produces power on demand hour upon hour and day in, day out. It is one of the most extensively used types of high‐speed rotating machinery as well as one of the most efficient converters of fuel into thrust. Reliability and long life with minimum maintenance depend on efficient monitoring of engine performance and component status.

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