Modelling of Coating Thickness, Heat Transfer and Fluid Flow and It's Correlation with the TBC Microstructure for a Plasma Sprayed Gas Turbine Application

1998 ◽  
Author(s):  
P. Nylen ◽  
J. Wigren ◽  
L. Pejryd ◽  
M.-O. Hansson
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Gas Turbine ◽  
Coating Thickness ◽  
Spray Deposition ◽  
Temperature History ◽  
Particle Model ◽  
Barrier Coating ◽  
Discrete Particle Model ◽  
Turbine Component

Abstract The plasma spray deposition of a zirconia thermal barrier coating (TBC) on a gas turbine component has been examined using analytical and experimental techniques. The coating thickness was simulated by the use of commercial off-line programming software. The impinging jet was modelled by means of a finite difference elliptic code using a simplified turbulence model. Powder particle velocity, temperature history and trajectory were calculated using a stochastic discrete particle model. The heat transfer and fluid flow model were then used to calculate transient coating and substrate temperatures using the finite element method. The predicted thickness, temperature and velocity of the particles and the coating temperatures were compared with these measurements and good correlations were obtained. The coating microstructure was evaluated by optical and scanning microscopy techniques. Special attention was paid to the crack structures within the top coating. Finally, the correlation between the modelled parameters and the deposit microstructure was studied.

Effects of Fluid Flow Characteristics and Heat Transfer of Integrated Impingement Cooling Structure for Micro Gas Turbine

CFD letters ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 104-115
Author(s):  
Hamidon Salleh ◽  
Amir Khalid ◽  
Syabillah Sulaiman ◽  
Bukhari Manshoor ◽  
Izzuddin Zaman ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Gas Turbine ◽  
Flow Characteristics ◽  
Impingement Cooling ◽  
Micro Gas Turbine ◽  
Fluid Flow Characteristics

A Multi-Timescale Approach for the Prediction of Temperatures in a Gas Turbine Combustor Liner

2020 ◽  
Author(s):  
Megan Karalus ◽  
Dustin Brandt ◽  
Alistair Brown ◽  
Vincent Lister
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Design Process ◽  
Conjugate Heat Transfer ◽  
Stable Solution ◽  
Heat Transfer Analysis ◽  
Eddy Simulation ◽  
Barrier Coating ◽  
Physical Response ◽  
Metal Liner

Abstract The desire for increased engine efficiencies is driving higher firing temperatures. But this increases the risk for hot spots in solid components which can lead to durability issues. These may not be discovered until late in the design process through expensive and time consuming thermal paint tests. Historically, conjugate heat transfer simulations to predict solid temperatures have been done with steady RANS. However, Large Eddy Simulation (LES) is now being used in the early design process for gas turbine engines to account for the multiphysics of reacting flows. Incorporating the solid into these simulations poses a new challenge: the physical response time of the solid components can be orders of magnitude larger than the reacting gas phase. Running a fully coupled unsteady conjugate heat transfer analysis is therefore not tractable, but the high fidelity of the LES reacting solution is still desired. The objective of this paper is to demonstrate a multi-timescale simulation approach for conjugate heat transfer (CHT) in Simcenter STAR-CCM+ 2019.3. The combustor is solved using LES, including all relevant physics, while steady state conduction is determined in the metal liner and thermal barrier coating. Time averaged boundary conditions are transferred from the combustor to the solids, and temperature is returned through multiple exchanges until the solid temperatures reach a stable solution. A simplified case is used to verify the approach, and then results from a test combustor are compared against data. The investigation compares results obtained with PISO and SIMPLE numerical schemes.

Robot Trajectory Generation and Coating Temperature Prediction of Plasma Sprayed Coatings

1997 ◽  
Author(s):  
P. Nylén ◽  
M. Edberg
Keyword(s):  
Coating Thickness ◽  
Simulation Method ◽  
Ideal Gas ◽  
Particle Model ◽  
Transfer Model ◽  
System A ◽  
Robot Trajectory ◽  
Offline Programming ◽  
Discrete Particle Model ◽  
Plasma Sprayed

Abstract This paper presents a simulation method in which robot trajectories can be optimised to produce an even coating thickness and how they can be used to predict transient coating temperatures on complex geometries. The coating thickness was simulated by the use of a commercial Offline programming (OLP) system. A robot trajectory was calculated, maintaining a constant spraying distance and normal orientation to the surface. The trajectory was optimised to give a uniform coating thickness while also handling non collision requirements. The plasma was represented as an ideal gas with temperature dependent thermodynamic and transport properties. The governing equations were solved by a developed finite difference elliptic code using a simplified turbulence model. The particles were modelled by a stochastic discrete particle model. The robot trajectory together with the heat transfer model were then used to calculate transient coating and substrate temperatures by the use of the finite element method (FEM). The model predictions were tentatively compared with experimental measurements and reasonable correlations were obtained.

Conformable Eddy-Current Sensors and Arrays for Fleetwide Gas Turbine Component Quality Assessment

2002 ◽  
Vol 124 (4) ◽  
pp. 904-909 ◽  
Author(s):  
N. Goldfine ◽  
D. Schlicker ◽  
Y. Sheiretov ◽  
A. Washabaugh ◽  
V. Zilberstein ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Gas Turbine ◽  
Eddy Current ◽  
Coating Thickness ◽  
Cold Work ◽  
Work Quality ◽  
Degradation Monitoring ◽  
Turbine Component ◽  
Current Sensors ◽  
Propeller Blades

The conformable Meandering Winding Magnetometer (MWM®) eddy current sensors and MWM-arrays provide new inspection capabilities for gas turbine components. The sensors provide measurements of coating thickness and absolute electrical conductivity, which can capture features of interest for a population of components, e.g., for tracking fleetwide trends in quality and aging, failure evaluations, and correlating failure origins to features of specific fleet population segments. Inspection applications include metallic and nonmetallic coating thickness and porosity measurement, detection of cracks on complex surfaces, imaging and detection of small flaws, thermal degradation monitoring, and cold work quality assessment. For example, the U.S. Air Force uses the MWM for cold work quality control on all of the C-130 propeller blades that go through the Warner Robins ALC. For P-3 and C-130 propeller blades, trend analysis is being performed fleetwide. This paper describes MWM technology advances for absolute property measurements and specific capability demonstrations. Multifrequency quantitative inversion methods used for coating characterization are also used for characterization of process-affected zones, such as shot peen quality or titanium alpha case characterization.

scholarly journals Thermal Analysis and Creep Lifetime Prediction Based on the Effectiveness of Thermal Barrier Coating on a Gas Turbine Combustor Liner Using Coupled CFD and FEM Simulation

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3817
Author(s):  
Kanmaniraja Radhakrishnan ◽  
Jun Su Park
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Thermal Expansion ◽  
Gas Turbine ◽  
Wall Temperature ◽  
Thermal Barrier ◽  
Gas Turbine Combustor ◽  
Average Temperature ◽  
Barrier Coating ◽  
Combustor Liner

Thermal barrier coating (TBC) plays a vital role in the gas turbine combustor liner (CL) to mitigate the internal heat transfer from combustion gas to the CL and enhance the parent material lifetime of the CL. This present study examined the thermal analysis and creep lifetime prediction based on three different TBC thicknesses, 400, 800, and 1200 μm, coated on the inner CL using the coupled computational fluid dynamics/finite element method. The simulation method was divided into three models to minimize the amount of computational work involved. The Eddy Dissipation Model was used in the first model to simulate premixed methane-air combustion, and the wall temperature of the inner CL was obtained. The conjugate heat transfer simulation on the external cooling flows from the rib turbulator, impingement jet, and cross flow, and the wall temperature of the outer CL was obtained in the second model. The thermal analysis was carried out in the third model using three different TBC thicknesses and incorporating the wall data from the first and second model. The effect of increasing TBC thickness shows that the TBC surface temperature was increased. Thereby, the inner CL metal temperature was decreased due to the TBC thickness as well as the material properties of Yttria Stabilized Zirconia, which has low thermal conductivity and a high thermal expansion coefficient. With the increase in TBC thickness, the average temperature difference between the TBC surface and the inner metal surface increased. In contrast, the average temperature difference between the inner and outer metal surfaces remained nearly constant. The von Mises equivalent stress, based on the material property and thermal expansion coefficient, was determined and used to find the creep lifetime of the CL using the Larson–Miller rupture curve for all TBC thickness cases in order to analyze the thermo-structure. Except in the C-channel, the increasing TBC thickness was found to effectively increase the CL lifespan. Furthermore, the case without TBC was compared with the damaged CL with cracks due to thermal stress, which was prevented by increasing TBC thickness shown in this present study.

Conformable Eddy-Current Sensors and Arrays for Fleetwide Gas Turbine Component Quality Assessment

2001 ◽  
Author(s):  
Neil Goldfine ◽  
Darrell Schlicker ◽  
Yanko Sheiretov ◽  
Andrew Washabaugh ◽  
Vladimir Zilberstein ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Gas Turbine ◽  
Eddy Current ◽  
Coating Thickness ◽  
Cold Work ◽  
Work Quality ◽  
Degradation Monitoring ◽  
Turbine Component ◽  
Current Sensors ◽  
Propeller Blades

The conformable Meandering Winding Magnetometer (MWM™) eddy current sensors and MWM-Arrays provide new inspection capabilities for gas turbine components. The sensors provide measurements of coating thickness and absolute electrical conductivity, which can capture features of interest for a population of components, e.g., for tracking fleetwide trends in quality and aging, failure evaluations and correlating failure origins to features of specific fleet population segments. Inspection applications include metallic and nonmetallic coating thickness and porosity measurement, detection of cracks on complex surfaces, imaging and detection of small flaws, thermal degradation monitoring, and cold work quality assessment. For example, the US Air Force uses the MWM for cold work quality control on all of the C-130 propeller blades that go through the Warner Robins ALC. For P-3 and C-130 propeller blades, trend analysis is being performed fleetwide. This paper describes MWM technology advances for absolute property measurements and specific capability demonstrations. Multifrequency quantitative inversion methods used for coating characterization are also used for characterization of process-affected zones, such as shot peen quality or titanium alpha case characterization.

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