scholarly journals Sintering Modeling of Thermal Barrier Coatings at Elevated Temperatures: A Review of Recent Advances

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1214
Author(s):  
Jinrong Yan ◽  
Xin Wang ◽  
Kuiying Chen ◽  
Kang N. Lee
Keyword(s):  
Gas Turbine ◽  
Elevated Temperatures ◽  
Gas Turbine Engine ◽  
Aviation Industry ◽  
Thermal Barrier ◽  
Inlet Temperature ◽  
Coating System ◽  
Turbine Engine ◽  
Modeling Methodology ◽  
Recent Advances

To achieve a higher efficiency in gas turbine engine by increasing the inlet-temperature of burning gas is one of the primary goals in aviation industry. The development of thermal barrier coating system (TBCs) continuously raises the inlet-temperature of gas turbine engine in the past decades. Due to the complexity of TBCs and harsh operation environments, the degradation and failure mechanisms of hot section components have not been fully understood, and consequently limits the application of TBCs. It was identified that high-temperature sintering of the topcoat in a typical TBC could be one of the major sources of its failure since the microstructures of the constituent coating layers evolve dynamically during the service period, resulting in significant changes of mechanical and thermal physical properties of the coating system. This paper intends to review recent advances of analytical and numerical modeling of sintering of topcoat in TBCs including the modeling methodology and applications of the models, particularly the implementation of finite element combined with specific materials constitutive functions. Critical remarks on the future development and applications of these models are also discussed in the end.

Design, Analysis, and Manufacture of an Axial Length-Saving Disk-Oriented Engine

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Bennett M. Staton ◽  
Brian T. Bohan ◽  
Marc D. Polanka ◽  
Larry P. Goss
Keyword(s):  
Gas Turbine ◽  
Axial Length ◽  
Electric Propulsion ◽  
Guide Vane ◽  
Combustion Process ◽  
Gas Turbine Engine ◽  
Inlet Temperature ◽  
Turbine Engine ◽  
Power Extraction ◽  
Turbine Inlet

Abstract A disk-oriented engine was designed to reduce the overall length of a gas turbine engine, combining a single-stage centrifugal compressor and radial in-flow turbine (RIT) in a back-to-back configuration. The focus of this research was to understand how this unique flow path impacted the combustion process. Computational analysis was accomplished to determine the feasibility of reducing the axial length of a gas turbine engine utilizing circumferential combustion. The desire was to maintain circumferential swirl from the compressor through a U-bend combustion path. The U-bend reverses the outboard flow from the compressor into an integrated turbine guide vane in preparation for power extraction by the RIT. The computational targets for this design were a turbine inlet temperature of 1300 K, operating with a 3% total pressure drop across the combustor, and a turbine inlet pattern factor (PF) of 0.24 to produce a cycle capable of creating 668 N of thrust. By wrapping the combustion chamber about the circumference of the turbomachinery, the axial length of the entire engine was reduced. Reallocating the combustor volume from the axial to radial orientation reduced the overall length of the system up to 40%, improving the mobility and modularity of gas turbine power in specific applications. This reduction in axial length could be applied to electric power generation for both ground power and airborne distributive electric propulsion. Computational results were further compared to experimental velocity measurements on custom fuel–air swirl injectors at mass flow conditions representative of 668 N of thrust, providing qualitative and quantitative insight into the stability of the flame anchoring system. From this design, a full-scale physical model of the disk-oriented engine was designed for combustion analysis.

The AGT101 Advanced Automotive Gas Turbine

1982 ◽  
Author(s):  
R. A. Rackley ◽  
J. R. Kidwell
Keyword(s):  
United States ◽  
Gas Turbine ◽  
The United States ◽  
Gas Turbine Engine ◽  
Development Project ◽  
Single Stage ◽  
Department Of Energy ◽  
Inlet Temperature ◽  
United States Department ◽  
Turbine Engine

The Garrett/Ford Advanced Gas Turbine Powertrain System Development Project, authorized under NASA Contract DEN3-167, is sponsored by and is part of the United States Department of Energy Gas Turbine Highway Vehicle System Program. Program effort is oriented at providing the United States automotive industry the technology base necessary to produce gas turbine powertrains competitive for automotive applications having: (1) reduced fuel consumption, (2) multi-fuel capability, and (3) low emissions. The AGT101 powertrain is a 74.6 kW (100 hp), regenerated single-shaft gas turbine engine operating at a maximum turbine inlet temperature of 1644 K (2500 °F), coupled to a split differential gearbox and Ford automatic overdrive production transmission. The gas turbine engine has a single-stage centrifugal compressor and a single-stage radial inflow turbine mounted on a common shaft. Maximum rotor speed is 10,472 rad/sec (100,000 rpm). All high-temperature components, including the turbine rotor, are ceramic. AGT101 powertrain development has been initiated, with testing completed on many aerothermodynamic components in dedicated test rigs and start of Mod I, Build 1 engine testing.

Full-Annulus URANS Study on the Transportation of Combustion Inhomogeneity in a Four-Stage Cooled Turbine

2019 ◽  
Author(s):  
Zhongran Chi ◽  
Haiqing Liu ◽  
Shusheng Zang ◽  
Chengxiong Pan ◽  
Guangyun Jiao
Keyword(s):  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Rotor Blades ◽  
Inlet Temperature ◽  
Computational Domain ◽  
Temperature Inhomogeneity ◽  
Unsteady Temperature ◽  
Turbine Engine ◽  
Exhaust Temperature ◽  
The Time Domain

Abstract The inhomogeneity of temperature in a turbine is related to the nonuniform heat release and air injections in combustors. In addition, it is influenced by the interactions between turbine cascades and coolant injections. Temperature inhomogeneity results in nonuniform flow temperature at turbine outlets, which is commonly measured by multiple thermal couples arranged in the azimuthal direction to monitor the operation of a gas turbine engine. Therefore, the investigation of temperature inhomogeneity transportation in a multistage gas turbine should help in detecting and quantifying the over-temperature or flameout of combustors using turbine exhaust temperature. Here the transportation of temperature inhomogeneity inside the four-stage turbine of a 300-MW gas turbine engine was numerically investigated using 3D CFD. The computational domain included all four stages of the turbine, consisting of more than 500 blades and vanes. Realistic components (N2, O2, CO2, and H2O) with variable heat capacities were considered for hot gas and cooling air. Coolants were added to the computational domain through more than 19,000 mass and momentum source terms. his was simple compared to realistic cooling structures. A URANS CFD run with over-temperature/flameout at 6 selected combustors out of 24 was carried out. The temperature distributions at rotor–stator interfaces and the turbine outlet were quantified and characterized by Fourier transformations in the time domain and space domain. It is found that the transport process from the hot-streaks/cold-streaks at the inlet to the outlet is relatively stable. The cold and hot fluid is redistributed in time and space due to the stator and rotor blades, in the region with a large parameter gradient at the inlet, strong unsteady temperature field and composition field appear. The distribution of the exhaust gas composition has a stronger correlation with the inlet temperature distribution and is less susceptible to interference.

Paper 7: Advanced Nickel-Chromium Base Alloys

1965 ◽  
Vol 180 (4) ◽  
pp. 160-171
Author(s):  
C. H. White ◽  
J. Heslop
Keyword(s):  
High Temperature ◽  
Binary System ◽  
Gas Turbine ◽  
Elevated Temperatures ◽  
High Strength ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
Nickel Chromium ◽  
Chromium Alloys ◽  
Resistance To Oxidation

Nickel-chromium alloys have been in use since early in this century for high temperature applications because of their resistance to oxidation. Since the advent of the gas-turbine engine, more complex alloys capable of maintaining high strength at elevated temperatures have been developed from the simple binary system. These complex alloys were initially mainly strengthened by the precipitation of the Ni3(Ti, Al) phase but more recent alloys have been further strengthened by additions of cobalt, tungsten, molybdenum, niobium, and tantalum. The properties and applications of these alloys are discussed.

Development of the Centaur Type H Gas Turbine Engine

1985 ◽  
Author(s):  
G. L. Padgett ◽  
W. W. Davis
Keyword(s):  
Gas Turbine ◽  
High Efficiency ◽  
State Of The Art ◽  
Gas Turbine Engine ◽  
Development Plan ◽  
Inlet Temperature ◽  
Market Place ◽  
Turbine Inlet Temperature ◽  
Turbine Engine ◽  
Computer Aided

In response to the needs of the market place for turbines in the 5000 to 6000 hp class, Solar Turbines Incorporated has responded with an uprate of their Centaur engine. Discussed in this paper are the features of the uprated engine, the Development Plan and the methodology for incorporating into the design the advanced aerodynamic and mechanical technology of the Mars engine. The Mars engine is a high efficiency 12,500 hp engine which operates at a turbine inlet temperature of 1935°F. State-of-the-art computer aided methods have been applied to produce the design, and the results from this approach are displayed.

Design of a State Space Controller for an Intercooled, Regenerated (ICR) Gas Turbine Engine

1994 ◽  
Author(s):  
Karl F. Prigge ◽  
Jerry W. Watts ◽  
Terrence E. Dwan
Keyword(s):  
Gas Turbine ◽  
Time Constant ◽  
Gas Turbine Engine ◽  
The Other ◽  
Pole Placement ◽  
Inlet Temperature ◽  
Fast Time ◽  
Turbine Engine ◽  
Power Turbine ◽  
Input Control

A multi-input, multi-output (MIMO) controller for an advanced gas turbine has been developed and tested using a computer simulation. The engine modeled is a two-and-one half spool gas turbine with both an intercooler and a regenerator. In addition, variable stator vanes are present in the free-power turbine. This advanced engine is proposed for future naval propulsion for both mechanical drive ships and electrical drive ships. The designed controller controls free-power turbine speed and turbine inlet temperature using fuel flow and angle of the stator vanes. The controller will also have four modes of operation to deal with over temperature and over speed conditions. An eight state reduced order controller was used with pole placement and LQR to arrive at control gains. Both these methods required considerable insight into the problem. This insight was provided by previous experience with controller design for a less complicated engine, and also by use of a polyhedral search model of the gas turbine engine. The difficulty with a MIMO controller was that both inputs affect both of the control variables. The classical resolution of this problem is to have one input control one variable at a fast time constant and the other input control the other variable at a slow time constant. The “optimal” resolution of this problem is analyzed using the transient curves and basic control theory.

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