Performance Evaluation of High Temperature Coatings for Hot Section Turbine Components

Author(s):  
David A. Shifler ◽  
Dennis M. Russom ◽  
Bruce E. Rodman

501-K34 marine gas turbine engines serve as auxiliary power sources for the U.S. Navy’s DDG-51 Class ships. It is desired that 501-K34 marine gas turbine engines have a mean time between removal of 20K hours. While some engines have approached this goal, others have fallen significantly short. A primary reason for this shortfall is hot corrosion (Type I and Type II) damage in the hot section turbine area due to both intrusion of salts from the marine air and from sulfur in the gas turbine combustion fuels. Previous metallographic examination of several unfailed blades removed from a marine gas turbine engine after 18000 operating hours showed that the coating thickness under the platform and in the curved area of transition between the platform to the blade stem was either very thin, porous, and in a few cases, non-existent on each unfailed blade. Type II hot corrosion was evident at these locations under the platform. Corrosion fatigue cracks initiated at several hot corrosion sites and had advanced through the blade stems to varying degrees. Cracking in a few blades had advanced to the point that blade failure was imminent. The objectives of this paper are to: (1) report the hot corrosion results of alternative high temperature coating systems on Alloy M247 and Alloy 792 for hot section components of the 501-K34 gas turbine engine using a low velocity, atmospheric-pressure burner-rig (LVBR), (2) compare and rank hot corrosion performance of these coatings systems to the baseline coating/substrate system (2) down select the best performing coating systems (in terms of LVBR hot corrosion and thermal cycling resistance) to implement on future hot section components in the 501-K34 engine for the Fleet.


Author(s):  
David A. Shifler ◽  
Dennis M. Russom ◽  
Bruce E. Rodman

501-K34 marine gas turbine engines serve as auxiliary power sources for the U.S. Navy’s DDG-51 Class. It is desired that 501-K34 marine gas turbine engines have a mean time between removal of 20K hours. While some engines have approached this goal, others have fallen significantly short. A primary reason for this shortfall is hot corrosion (Type I and Type II) damage in the turbine area (more specifically the first row turbine hardware) due to both intrusion of salts from the marine air and from sulfur in the gas turbine combustion fuels. In order to improve the durability of hot section components with more corrosion resistant coatings, low velocity, atmospheric-pressure burner-rig (LVBR) tests were conducted for up to 2000 hours to evaluate several alternative high-temperature coatings in both Type I and Type II hot corrosion environments. The objectives of this paper are to report the results of: (1) the hot corrosion performance of these alternative high temperature coating systems for the 1st stage vane of a given gas turbine engine; (2) compare the performance of these alternative coating systems to the current, baseline 1st stage vane coating and (3) downselect the best performing coating systems (in terms of their LVBR hot corrosion and thermal cycling resistance) to install as rainbow arrays into the first stage vanes of several engines for Fleet evaluation.



Author(s):  
David A. Shifler ◽  
Dennis M. Russom ◽  
Bruce E. Rodman

501-K34 marine gas turbine engines serve as auxiliary power sources for the U.S. Navy’s DDG-51 Class. It is desired that 501-K34 marine gas turbine engines have a mean time between removal of 20K hours. While some engines have approached this goal, others have fallen significantly short. A primary reason for this shortfall is hot corrosion (Type I and Type II) damage in the turbine area (more specifically the first row turbine hardware) due to both intrusion of salts from the marine air and from sulfur in the gas turbine combustion fuel. The Navy’s technical community recognizes that engine corrosion problems are complex in nature and are often tied to the design of the overall system. For this reason, two working groups were formed. One group focuses on the overall ship system design and operation, including the inlet and fuel systems. The second, the corrosion issues working group, will review the design and performance of the turbine itself and develop sound, practical, economical, and executable changes to engine design that will make it more robust and durable in the shipboard operating environment. Metallographic examination of unfailed blades removed from a marine gas turbine engine with 18000 operating hours showed that the coating thickness under the platform and in the curved area of transition between the platform to the blade stem was either very thin, or in a few cases, non-existent on each unfailed blade. Type II hot corrosion was evident at these locations under the platform. It was also observed that this corrosion under the platform led to corrosion fatigue cracking of first stage turbine blades due to poor coating quality (high porosity and variable thickness). Corrosion fatigue cracks initiated at several hot corrosion sites and had advanced through the stems to varying degrees. Cracking in a few blades had advanced to the point that would have led to premature blade failure. Low velocity, atmospheric-pressure burner-rig (LVBR) tests were conducted for 1000 hours to evaluate several alternative high-temperature coatings in both Type I and Type II hot corrosion environments. The objectives of this paper are to: (1) report the results of the hot corrosion performance of alternative high temperature coating systems for under the platform of the 1st stage blade of 501-K34 gas turbine engine, (2) compare the performance of these alternative coating systems to the current baseline 1st stage blade coating, and (3) down select the best performing coating systems (in terms of their LVBR hot corrosion and thermal cycling resistance) to implement on future 501-K34 first stage blades for the Fleet.



2013 ◽  
Vol 325-326 ◽  
pp. 1368-1373
Author(s):  
Yağız Uzunonat ◽  
Sinem Üzgür ◽  
M.C. Kushan

In this study, the basic limitations of superalloys in high temperature performances will be explained and then after giving the important properties of MoSi2such as oxidation behaviour at relatively low temperatures (500°C-700°C) , some interesting composites of this material will be discussed as a candidate structural material in gas turbine engines.



2021 ◽  
Author(s):  
Jeffrey S. Patterson ◽  
Kevin Fauvell ◽  
Dennis Russom ◽  
Willie A. Durosseau ◽  
Phyllis Petronello ◽  
...  

Abstract The United States Navy (USN) 501-K Series Radiological Controls (RADCON) Program was launched in late 2011, in response to the extensive damage caused by participation in Operation Tomodachi. The purpose of this operation was to provide humanitarian relief aid to Japan following a 9.0 magnitude earthquake that struck 231 miles northeast of Tokyo, on the afternoon of March 11, 2011. The earthquake caused a tsunami with 30 foot waves that damaged several nuclear reactors in the area. It was the fourth largest earthquake on record (since 1900) and the largest to hit Japan. On March 12, 2011, the United States Government launched Operation Tomodachi. In all, a total of 24,000 troops, 189 aircraft, 24 naval ships, supported this relief effort, at a cost in excess of $90.0 million. The U.S. Navy provided material support, personnel movement, search and rescue missions and damage surveys. During the operation, 11 gas turbine powered U.S. warships operated within the radioactive plume. As a result, numerous gas turbine engines ingested radiological contaminants and needed to be decontaminated, cleaned, repaired and returned to the Fleet. During the past eight years, the USN has been very proactive and vigilant with their RADCON efforts, and as of the end of calendar year 2019, have successfully completed the 501-K Series portion of the RADCON program. This paper will update an earlier ASME paper that was written on this subject (GT2015-42057) and will summarize the U.S. Navy’s 501-K Series RADCON effort. Included in this discussion will be a summary of the background of Operation Tomodachi, including a discussion of the affected hulls and related gas turbine equipment. In addition, a discussion of the radiological contamination caused by the disaster will be covered and the resultant effect to and the response by the Marine Gas Turbine Program. Furthermore, the authors will discuss what the USN did to remediate the RADCON situation, what means were employed to select a vendor and to set up a RADCON cleaning facility in the United States. And finally, the authors will discuss the dispensation of the 501-K Series RADCON assets that were not returned to service, which include the 501-K17 gas turbine engine, as well as the 250-KS4 gas turbine engine starter. The paper will conclude with a discussion of the results and lessons learned of the program and discuss how the USN was able to process all of their 501-K34 RADCON affected gas turbine engines and return them back to the Fleet in a timely manner.



2020 ◽  
Vol 19 (4) ◽  
pp. 43-57
Author(s):  
H. H. Omar ◽  
V. S. Kuz'michev ◽  
A. O. Zagrebelnyi ◽  
V. A. Grigoriev

Recent studies related to fuel economy in air transport conducted in our country and abroad show that the use of recuperative heat exchangers in aviation gas turbine engines can significantly, by up to 20...30%, reduce fuel consumption. Until recently, the use of cycles with heat recovery in aircraft gas turbine engines was restrained by a significant increase in the mass of the power plant due to the installation of a heat exchanger. Currently, there is a technological opportunity to create compact, light, high-efficiency heat exchangers for use on aircraft without compromising their performance. An important target in the design of engines with heat recovery is to select the parameters of the working process that provide maximum efficiency of the aircraft system. The article focused on setting of the optimization problem and the choice of rational parameters of the thermodynamic cycle parameters of a gas turbine engine with a recuperative heat exchanger. On the basis of the developed method of multi-criteria optimization the optimization of thermodynamic cycle parameters of a helicopter gas turbine engine with a ANSAT recuperative heat exchanger was carried out by means of numerical simulations according to such criteria as the total weight of the engine and fuel required for the flight, the specific fuel consumption of the aircraft for a ton- kilometer of the payload. The results of the optimization are presented in the article. The calculation of engine efficiency indicators was carried out on the basis of modeling the flight cycle of the helicopter, taking into account its aerodynamic characteristics. The developed mathematical model for calculating the mass of a compact heat exchanger, designed to solve optimization problems at the stage of conceptual design of the engine and simulation of the transport helicopter flight cycle is presented. The developed methods and models are implemented in the ASTRA program. It is shown that optimal parameters of the working process of a gas turbine engine with a free turbine and a recuperative heat exchanger depend significantly on the heat exchanger effectiveness. The possibility of increasing the efficiency of the engine due to heat regeneration is also shown.



Author(s):  
J. A. Saintsbury ◽  
P. Sampath

The impact of potential aviation gas turbine fuels available in the near to midterm, is reviewed with particular reference to the small aviation gas turbine engine. The future course of gas turbine combustion R&D, and the probable need for compromise in fuels and engine technology, is also discussed. Operating experience to date on Pratt & Whitney Aircraft of Canada PT6 engines, with fuels not currently considered of aviation quality, is reported.



Author(s):  
M. P. Enright ◽  
R. C. McClung ◽  
S. J. Hudak ◽  
H. R. Millwater

The risk of fracture associated with high energy rotating components in aircraft gas turbine engines can be sensitive to small changes in applied stress values which are often difficult to measure and predict. Although a parametric approach is often used to characterize random variables, it is difficult to apply to multimodal densities. Nonparametric methods provide a direct fit to the data, and can be used to estimate the multimodal densities often associated with rainflow stress data. In this paper, a comparison of parametric and nonparametric methods is presented for density estimation of rainflow stress profiles associated with military aircraft gas turbine engine usages. A nonparametric adaptive kernel density estimator algorithm is illustrated for standard parametric probability density functions and for rainflow stress pairs associated with F-16/F100 engine usages. The kernel estimates are compared to parametric estimates, including a hybrid approach based on separate treatment of maximum stress pairs. The results provide some insight regarding the strengths and weaknesses of parametric and nonparametric density estimation methods for gas turbine engines, and can be used to develop improved stress estimates for probabilistic life predictions.



Aviation ◽  
2013 ◽  
Vol 17 (2) ◽  
pp. 52-56 ◽  
Author(s):  
Mykola Kulyk ◽  
Sergiy Dmitriev ◽  
Oleksandr Yakushenko ◽  
Oleksandr Popov

A method of obtaining test and training data sets has been developed. These sets are intended for training a static neural network to recognise individual and double defects in the air-gas path units of a gas-turbine engine. These data are obtained by using operational process parameters of the air-gas path of a bypass turbofan engine. The method allows sets that can project some changes in the technical conditions of a gas-turbine engine to be received, taking into account errors that occur in the measurement of the gas-dynamic parameters of the air-gas path. The operation of the engine in a wide range of modes should also be taken into account.



2021 ◽  
Vol 20 (3) ◽  
pp. 152-159
Author(s):  
A. M. Faramazyan ◽  
S. S. Remchukov ◽  
I. V. Demidyuk

The application of casting technologies in the production of parts and assemblies of small-size gas turbine engines is justified in the paper. The technology of vacuum casting in gypsum molds was tested during the production of an experimental centrifugal compressor of a small-size gas turbine engine. On the basis of a 3D model of the designed centrifugal compressor, computational studies of vacuum casting were carried out and rational parameters of the technological process were determined. Prototypes of the developed centrifugal compressor of a small-size gas turbine engine were made. The results of calculations and the performed technological experiment confirmed the fill rate of the gating form and the absence of short pour. The distribution of shrinkage porosity and cavities corresponds to the design values and is concentrated in the central part of the casting that is subjected to subsequent machining. The area of the blades, disc and sleeve is formed without defects. The use of casting technologies in the production of parts and assemblies of small-size gas turbine engines assures the required quality with a comparatively low price of the finished product, making it possible to achieve the balance between the cost of the technology and the quality of the product made according to this technology.



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