Multi-Physics Simulation Based Approach for Life Prediction of a Gas Turbine Combustor Liner

2019 ◽  
Author(s):  
Sourabh Shrivastava ◽  
Prem Andrade ◽  
Vinay Carpenter ◽  
Ravindra Masal ◽  
Pravin Nakod ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Structural Analysis ◽  
Life Prediction ◽  
Conjugate Heat Transfer ◽  
Load Cycle ◽  
Gas Turbine Combustor ◽  
Simulation Based ◽  
Aero Engine ◽  
Physics Simulation ◽  
Combustor Liner

Abstract Better life assessment of hot-components of an aero-engine can help improve its reliability and service life, while, reducing associated maintenance cost. Accurate prediction of Thermo-Mechanical Fatigue (TMF) is one of the crucial aspects of life prediction. Therefore, fully resolved simulation methodologies have gained attention as an ingredient for solving TMF problems owing to their potential for providing comprehensive insights into a system having hot components undergoing transient loading during operation. The present work focuses on a multi-physics simulation-based approach for the life-prediction of a representative gas-turbine combustor liner with an objective of providing a complete framework for TMF analysis of an actual aero-engine combustor liner. The presented methodology consists of a coupling between Computational Fluid Dynamics (CFD) and Finite Element Method (FEM). Thermal loads on the representative aero-engine combustor are predicted using Conjugate Heat Transfer (CHT) modeling in the CFD analyses for different operating conditions suitable for a flight cycle. A load cycle is then constructed using these thermal loads and is transferred to the structural analysis to evaluate the stresses in the liner. Results are obtained regarding spatially varying thermal expansion resulting in inelastic strains as governed by temperature and rate dependent material behavior. Stress and plastic strain history information from the structural analysis are processed to predict the life of different regions of the combustor liner. Different simulation methods for conjugate heat-transfer, load-cycle, material property extraction, thermal-stresses, and fatigue are evaluated, and an overall methodology involving accuracy and reasonable computational cost is proposed. The proposed methodology is numerically verified, and the verification results are presented in this work.

Conjugate Heat Transfer Analysis of Military Aero Engine Combustor Liner With Impingement and Effusion Cooling

2019 ◽  
Author(s):  
Batchu Suresh ◽  
Chinmayee Panigrahi ◽  
Antonio Davis ◽  
V. Kesavan ◽  
D. Kishore Prasad
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Hole Diameter ◽  
Heat Transfer Analysis ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Impingement Plate ◽  
Aero Engine ◽  
Combustor Liner

Abstract Improvement in specific thrust is one of the desirable requirements for Military aero-engine which has led to a tremendous increase in turbine inlet temperatures. This has resulted in combustion chambers to operate at a gas temperature of the order of 2100K, making it difficult for the thermal designers to design a liner cooling configuration to bring down its metal temperature within allowable limits with available coolant air. The present study highlights the computational prediction of cooling effectiveness for impingement-effusion cooled combustor liner. The impingement cooling is adopted to the effusion cooled liner in order to enhance its coolant side heat transfer. 1-Dimensional (1-D) analysis is carried out to obtain a suitable impingement geometry to improve the coolant side heat transfer. Suitable geometrical features like impingement hole diameter (di) and distance of the impingement plate from effusion liner (z) are arrived for enhancement of coolant side heat transfer. Conjugate Heat Transfer analysis (CHT) is carried out for three cooling configurations with different impingement hole diameter. Effusion cooled liner with porosity 1% and holes inclined at 22° and for impingement plate hole porosity of 1.6% is maintained for all the configurations. CHT analysis is carried out for effusion cooled liner using ANSYS Fluent ver.14.5. The film cooling predictions are in good agreement for effusion cooled liner plate with measurements. SST k-ω turbulence model with enhanced wall function predicted well. The effectiveness obtained for effusion cooled liner and impingement-effusion cooled liner are compared. There is an improvement of 34% in effectiveness for impingement-effusion cooled liner compared to effusion cooled liner with a reduction of coolant air mass flow by 10%. The variation of temperature for the impingement-effusion cooled liner is lower. Parametric analysis is also carried out to study the effect of blowing ratio and metal thermal conductivity on the film cooling effectiveness for impingement-effusion cooled liner.

Combustor Cooling Wiggle Strip and Geometrical Simplification

2008 ◽  
Author(s):  
Leiyong Jiang
Keyword(s):  
Conjugate Heat Transfer ◽  
Flow Fields ◽  
Considerable Effect ◽  
Temperature Fields ◽  
Gas Turbine Combustor ◽  
Temperature Prediction ◽  
Average Temperature ◽  
Velocity And Temperature Fields ◽  
Cooling Element ◽  
Combustor Liner

The flow fields of a combustor cooling wiggle strip and its corresponding simplified slot with conjugate heat transfer have been studied numerically. The effects of geometrical simplification on the flow fields have been analysed qualitatively and quantitatively. It is found that its effects on the flow velocity and temperature fields are limited to local regions near the cooling element, and are negligible in the far field. However, the simplification shows a considerable effect on the combustor liner temperature near the cooling element, about 8.5% of the average temperature across the cooling element. In short, using the simplified slot to replace the cooling wiggle strip in gas turbine combustor modeling is an acceptable practice if accurate liner temperature prediction is not required.

Numerical Investigation of Gas Turbine Combustor Liner Film Cooling Slots

2018 ◽  
Author(s):  
Firat Kiyici ◽  
Ahmet Topal ◽  
Ender Hepkaya ◽  
Sinan Inanli
Keyword(s):  
Heat Transfer ◽  
Prandtl Number ◽  
Surface Temperature ◽  
Gas Turbine ◽  
Film Cooling ◽  
Turbulent Prandtl Number ◽  
Surface Cooling ◽  
Gas Turbine Combustor ◽  
Cooling Effectiveness ◽  
Combustor Liner

A numerical study, based on experimental work of Inanli et al. [1] is conducted to understand the heat transfer characteristics of film cooled test plates that represent the gas turbine combustor liner cooling system. Film cooling tests are conducted by six different slot geometries and they are scaled-up model of real combustor liner. Three different blowing ratios are applied to six different geometries and surface cooling effectiveness is determined for each test condition by measuring the surface temperature distribution. Effects of geometrical and flow parameters on cooling effectiveness are investigated. In this study, Conjugate Heat Transfer (CHT) simulations are performed with different turbulence models. Effect of the turbulent Prandtl Number is also investigated in terms of heat transfer distribution along the measurement surface. For this purpose, turbulent Prandtl number is calculated with a correlation as a function of local surface temperature gradient and its effect also compared with the constant turbulent Prandtl numbers. Good agreement is obtained with two-layered k–ϵ with modified Turbulent Prandtl number.

Numerical Prediction of Combustor Heatshield Flow and Heat Transfer With Sub-Grid-Scale Modelling of Pedestals

2001 ◽  
Author(s):  
John K. Luff ◽  
James J. McGuirk
Keyword(s):  
Heat Transfer ◽  
Life Prediction ◽  
Conjugate Heat Transfer ◽  
Energy Equation ◽  
Flow And Heat Transfer ◽  
Extra Energy ◽  
Scale Modelling ◽  
Heat Transfer Calculation ◽  
Proper Account ◽  
Good Agreement

A goal for computational analysis of combustors is to produce a tool for life prediction. An important part of this will be the prediction of the temperature field in the combustor walls. The complex geometries of combustor components make this a formidable task. In this paper a 3D coupled numerical flow/conjugate heat transfer calculation procedure is presented for a combustor heatshield. Proper account must be taken of the blockage and heat transfer effects of pedestals. A scheme has been developed to account for these effects without resolving the pedestals in the computational grid. Extra sink terms are included in the momentum equations to account for pedestal pressure drop. An extra energy equation is solved to determine the local pedestal temperature and to account for heat transfer between pedestals and fluid. This treatment has been validated against empirical data for arrays of pedestals in ducts with good agreement for friction factor and Nusselt number. The methodology is then applied to a generic heatshield geometry to indicate that a viable computational route has been developed for combustor heatshield analysis.

Experimental and Numerical Study of Heat Transfer in a Gas Turbine Combustor Liner

2003 ◽  
Vol 125 (4) ◽  
pp. 994-1002 ◽  
Author(s):  
J. C. Bailey ◽  
J. Intile ◽  
T. F. Fric ◽  
A. K. Tolpadi ◽  
N. V. Nirmalan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Numerical Study ◽  
Cross Flow ◽  
Turbulence Models ◽  
Flow Distribution ◽  
Transfer Coefficients ◽  
Gas Turbine Combustor ◽  
Heat Transfer Coefficients ◽  
Combustor Liner

Experiments and numerical simulations were conducted to understand the heat transfer characteristics of a stationary gas turbine combustor liner cooled by impingement jets and cross flow between the liner and sleeve. Heat transfer was also aided by trip-strip turbulators on the outside of the liner and in the flowsleeve downstream of the jets. The study was aimed at enhancing heat transfer and prolonging the life of the combustor liner components. The combustor liner and flow sleeve were simulated using a flat-plate rig. The geometry has been scaled from actual combustion geometry except for the curvature. The jet Reynolds number and the mass-velocity ratios between the jet and cross flow in the rig were matched with the corresponding combustor conditions. A steady-state liquid crystal technique was used to measure spatially resolved heat transfer coefficients for the geometric and flow conditions mentioned above. The heat transfer was measured both in the impingement region as well as over the turbulators. A numerical model of the combustor test rig was created that included the impingement holes and the turbulators. Using CFD, the flow distribution within the flow sleeve and the heat transfer coefficients on the liner were both predicted. Calculations were made by varying the turbulence models, numerical schemes, and the geometrical mesh. The results obtained were compared to the experimental data and recommendations have been made with regard to the best modeling approach for such liner-flow sleeve configurations.

On Uncertainty and Local Sensitivity Analysis for Steady-State Conjugate Heat Transfer Problems

2010 ◽  
Author(s):  
Christian Rauch ◽  
Raimund Almbauer
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Conjugate Heat Transfer ◽  
Relative Importance ◽  
Physics Simulation ◽  
The Stability ◽  
Transfer Problems ◽  
Solution Matrix ◽  
Significant Effort ◽  
Stability Of The Solution

In recent years, significant effort has been put into developing automated multi-physics simulation. The exchange of boundary conditions has lead to more realistic as well as more complex simulations with usually slower convergence rate when the coupling is being performed between two different codes. In this paper the equations of local sensitivities for element centered steady-state combined convection, conduction, and thermal radiation problems are being derived along with some implementation details. A numerical analysis on the stability of the solution matrix is being conducted. The relative importance of the heat transfer modes at various locations are investigated by their uncertainty factors and conclusions are being drawn.

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.

Experimental and Numerical Study of Heat Transfer in a Gas Turbine Combustor Liner

2002 ◽  
Author(s):  
Jeremy C. Bailey ◽  
John Intile ◽  
Thomas F. Fric ◽  
Anil K. Tolpadi ◽  
Nirm V. Nirmalan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Numerical Study ◽  
Cross Flow ◽  
Turbulence Models ◽  
Flow Distribution ◽  
Transfer Coefficients ◽  
Gas Turbine Combustor ◽  
Heat Transfer Coefficients ◽  
Combustor Liner

Experiments and numerical simulations were conducted to understand the heat transfer characteristics of a stationary gas turbine combustor liner cooled by impingement jets and cross flow between the liner and sleeve. Heat transfer was also aided by trip-strip turbulators on the outside of the liner and in the flowsleeve downstream of the jets. The study was aimed at enhancing heat transfer and prolonging the life of the combustor liner components. The combustor liner and flow sleeve were simulated using a flat plate rig. The geometry has been scaled from actual combustion geometry except for the curvature. The jet Reynolds number and the mass-velocity ratios between the jet and cross flow in the rig were matched with the corresponding combustor conditions. A steady state liquid crystal technique was used to measure spatially resolved heat transfer coefficients for the geometric and flow conditions mentioned above. The heat transfer was measured both in the impingement region as well as over the turbulators. A numerical model of the combustor test rig was created that included the impingement holes and the turbulators. Using CFD, the flow distribution within the flow sleeve and the heat transfer coefficients on the liner were both predicted. Calculations were made by varying the turbulence models, numerical schemes, and the geometrical mesh. The results obtained were compared to the experimental data and recommendations have been made with regard to the best modeling approach for such liner-flow sleeve configurations.

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