Thermal Analysis of Cooling System in a Gas Turbine Transition Piece

2011 ◽  
Author(s):  
Jun Su Park ◽  
Namgeon Yun ◽  
Hokyu Moon ◽  
Kyung Min Kim ◽  
Sin-Ho Kang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Thermal Stresses ◽  
Cooling System ◽  
Structural Information ◽  
Thermal Analyses ◽  
Thermal Design ◽  
Transfer Coefficients ◽  
Transition Piece ◽  
Inlet Conditions

This paper presents thermal analyses of the cooling system of a transition piece, which is one of the primary hot components in a gas turbine engine. The thermal analyses include heat transfer distributions induced by heat and fluid flow, temperature, and thermal stresses. The purpose of this study is to provide basic thermal and structural information on transition piece, to facilitate their maintenance and repair. The study is carried out primarily by numerical methods, using the commercial software, Fluent and ANSYS. First, the combustion field in a combustion liner with nine fuel nozzles is analyzed to determine the inlet conditions of a transition piece. Using the results of this analysis, pressure distributions inside a transition piece are calculated. The outside of the transition piece in a dump diffuser system is also analyzed. Information on the pressure differences is then used to obtain data on cooling channel flow (one of the methods for cooling a transition piece). The cooling channels have exit holes that function as film-cooling holes. Thermal and flow analyses are carried out on the inside of a film-cooled transition piece. The results are used to investigate the adjacent temperatures and wall heat transfer coefficients inside the transition piece. Overall temperature and thermal stress distributions of the transition piece are obtained. These results will provide a direction to improve thermal design of transition piece.

Evaluation of Numerical Methods to Predict Temperature Distributions of an Experimentally Investigated Convection-Cooled Gas-Turbine Blade

2017 ◽  
Author(s):  
E. Findeisen ◽  
B. Woerz ◽  
M. Wieler ◽  
P. Jeschke ◽  
M. Rabs
Keyword(s):  
Heat Transfer ◽  
Numerical Methods ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Gas Turbines ◽  
Cooling System ◽  
Fe Model ◽  
Gas Turbine Blade ◽  
Transfer Coefficients ◽  
Temperature Distributions

This paper presents two different numerical methods to predict the thermal load of a convection-cooled gas-turbine blade under realistic operating temperature conditions. The subject of the investigation is a gas-turbine rotor blade equipped with an academic convection-cooling system and investigated at a cascade test-rig. It consists of three cooling channels, which are connected outside the blade, so allowing cooling air temperature measurements. Both methods use FE models to obtain the temperature distribution of the solid blade. The difference between these methods lies in the generation of the heat transfer coefficients along the cooling channel walls which serve as a boundary condition for the FE model. One method, referred to as the FEM1D method, uses empirical one-dimensional correlations known from the available literature. The other method, the FEM2D method, uses three-dimensional CFD simulations to obtain two-dimensional heat transfer coefficient distributions. The numerical results are compared to each other as well as to experimental data, so that the benefits and limitations of each method can be shown and validated. Overall, this paper provides an evaluation of the different methods which are used to predict temperature distributions in convection-cooled gas-turbines with regard to accuracy, numerical cost and the limitations of each method. The temperature profiles obtained in all methods generally show good agreement with the experiments. However, the more detailed methods produce more accurate results by causing higher numerical costs.

Conjugate Heat Transfer Methodology for Thermal Design and Verification of Gas Turbine Cooled Components

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Lorenzo Winchler ◽  
Antonio Andreini ◽  
Bruno Facchini ◽  
Luca Andrei ◽  
Alessio Bonini ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Cooling System ◽  
Measurement Data ◽  
Thermal Design ◽  
Heat Transfer Analysis ◽  
Internal Cooling ◽  
Cfd Analysis ◽  
Continuous Increase

Gas turbine design has been characterized over the years by a continuous increase of the maximum cycle temperature, justified by a corresponding increase of cycle efficiency and power output. In such way, turbine components heat load management has become a compulsory activity, and then, a reliable procedure to evaluate the blades and vanes metal temperatures is, nowadays, a crucial aspect for a safe components design. In the framework of the design and validation process of high pressure turbine cooled components of the BHGE NovaLTTM 16 gas turbine, a decoupled methodology for conjugate heat transfer prediction has been applied and validated against measurement data. The procedure consists of a conjugate heat transfer analysis in which the internal cooling system (for both airfoils and platforms) is modeled by an in-house one-dimensional thermo-fluid network solver, the external heat loads and pressure distribution are evaluated through 3D computational fluid dynamics (CFD) analysis and the heat conduction in the solid is carried out through a 3D finite element method (FEM) solution. Film cooling effect has been treated by means of a dedicated CFD analysis, implementing a source term approach. Predicted metal temperatures are finally compared with measurements from an extensive test campaign of the engine in order to validate the presented procedure.

Conjugate Heat Transfer Methodology for Thermal Design and Verification of Gas Turbine Cooled Components

2018 ◽  
Author(s):  
Lorenzo Winchler ◽  
Antonio Andreini ◽  
Bruno Facchini ◽  
Luca Andrei ◽  
Alessio Bonini ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Cooling System ◽  
Measurement Data ◽  
Thermal Design ◽  
Heat Transfer Analysis ◽  
Cfd Analysis ◽  
3D Fem ◽  
Continuous Increase

Gas turbine design has been characterized over the years by a continuous increase of the maximum cycle temperature, justified by a corresponding increase of cycle efficiency and power output. In such way turbine components heat load management has become a compulsory activity and then, a reliable procedure to evaluate the blades and vanes metal temperatures, is, nowadays, a crucial aspect for a safe components design. In the framework of the design and validation process of HPT (High Pressure Turbine) cooled components of the BHGE NovaLT™ 16 gas turbine, a decoupled methodology for conjugate heat transfer prediction has been applied and validated against measurement data. The procedure consists of a conjugate heat transfer analysis in which the internal cooling system (for both airfoils and platforms) is modeled by an in-house one-dimensional thermo-fluid network solver, the external heat loads and pressure distribution are evaluated through 3D CFD analysis and the heat conduction in the solid is carried out through a 3D FEM solution. Film cooling effect has been treated by means of a dedicated CFD analysis, implementing a source term approach. Predicted metal temperatures are finally compared with measurements from an extensive test campaign of the engine, in order to validate the presented procedure.

Conjugate Heat Transfer Analysis for Gas Turbine Cooled Blade

2014 ◽  
Author(s):  
Kuo-San Ho ◽  
Christopher Urwiller ◽  
S. Murthy Konan ◽  
Jong S. Liu ◽  
Bruno Aguilar
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Fluid Dynamic ◽  
Thermal Analyses ◽  
Convection Heat Transfer ◽  
Heat Transfer Analysis ◽  
Engine Test ◽  
Transfer Coefficients ◽  
Sst Turbulence Model

This paper explores the conjugate heat transfer (CHT) numerical simulation approach to calculate the metal temperature for a cooled gas turbine blade. ANSYS CFX14.0 code was selected as the computational fluid dynamic (CFD) tool to perform the CHT simulation. The two-equation SST turbulence model with automatic wall treatment was employed. A full engine test with Silicon Carbide (SiC) chip measurements was performed and used to validate the CHT results. Metal temperatures calculated with the CHT model were compared to engine test data. The results demonstrated good agreement between predicted and measured airfoil metal temperatures. The blade cooling flow prediction was matched to the flow network analysis. This paper describes a process to calculate convection heat transfer coefficients (HTC) for cooling passages and airfoil surfaces using CHT results. This process was made possible because local wall heat flux and fluid temperatures were known. This approach assisted in calibrating an in-house conduction thermal model for steady state thermal analyses.

Study on Relevant Effects Concerning Heat Transfer of a Convection Cooled Gas Turbine Blade Under Realistic Engine Temperature Conditions

2013 ◽  
Author(s):  
Y. Mick ◽  
B. Wörz ◽  
E. Findeisen ◽  
P. Jeschke ◽  
V. Caspary
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Thermal Stresses ◽  
Cooling System ◽  
Gas Turbine Blade ◽  
Temperature Conditions ◽  
The Impact ◽  
Operating Points

This paper presents a study of the temperature distribution of a convection cooled gas turbine blade under realistic operating temperature conditions using experimental and numerical methods. The analysis is performed experimentally in a linear cascade with exhaust gas from a kerosene combustor. Detailed information at different operating points is taken from the experiments for which conjugate heat transfer (CHT) simulations with ANSYS CFX are carried out. By comparing the experimental and numerical results, the required complexity of the simulations is defined. The subject of this study is a gas turbine rotor blade equipped with a state-of-the-art internal convection cooling system. The test rig enables the examination of the blade at temperatures up to 1300K. The temperature distribution of the blade is measured using thermocouples. The calculations are carried out using the SST turbulence model, the Gamma Theta transition model and the discrete transfer radiation model. The influence of hot gas properties and radiation effects are analysed at three different operating points. This paper gives a quantitative overview of the impact of the mentioned parameters on temperature level and distribution as well as thermal stresses in a convection cooled blade under realistic engine temperature conditions.

scholarly journals Comparison of Blade Cooling Performance Using Alternative Fluids

2002 ◽  
Author(s):  
Carlo Carcasci ◽  
Stefano Zecchi ◽  
Gianpaolo Oteri
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Gas Turbine ◽  
Film Cooling ◽  
Cooling System ◽  
Internal Heat ◽  
Transfer Coefficients ◽  
Cooling Systems ◽  
Heat Transfer Coefficients ◽  
Blade Cooling

CO2 emissions reduction has become an important topic, especially after Kyoto protocol. There are several ways to reduce the overall amount of CO2 discharged into the atmosphere, for example using alternative fluids such as steam or CO2. It is therefore interesting to analyze the consequences of their usage on overall performances of gas turbine and blade cooling systems. The presence of steam can be associated with combined or STIG cycle, whereas pure carbon dioxide or air-carbon dioxide mixtures are present in innovative cycles, where the exhaust gas is recirculated partially or even totally. In this paper we will analyze a commercial gas turbine, comparing different fluids used as working and cooling fluids. The different nature of the fluids involved determines different external heat transfer coefficients (external blade surface), different internal heat transfer coefficients (cooling cavities) and affects film cooling effectiveness, resulting in a change of the blade temperature distribution. Results show that the presence of steam and CO2 could determine a non negligible effect on blade temperature. This means that cooling systems need a deep investigation. A redesign of the cooling system could be required. In particular, results show that steam is well suited for internal cooling, whereas CO2 is better used in film cooling systems.

Validation of CFD and Coupled Fluid-Solid Modelling for a Direct Transfer Pre-Swirl System

2012 ◽  
Author(s):  
Umesh Javiya ◽  
John Chew ◽  
Nick Hills ◽  
Klaus Dullenkopf ◽  
Timothy Scanlon
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Thermal Stresses ◽  
Cooling System ◽  
Life Assessment ◽  
Direct Transfer ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Thermocouple Temperature ◽  
Cooling Air

The prediction of the pre-swirl cooling air delivery and disc metal temperature are important for the cooling system performance and the rotor disc thermal stresses and life assessment. In this paper, standalone 3D steady and unsteady CFD, and coupled FE-CFD calculations are presented for prediction of these temperatures. CFD results are compared with previous measurements from a direct transfer pre-swirl test rig. The predicted cooling air temperatures agree well with the measurement, but the nozzle discharge coefficients are under predicted. Results from the coupled FE-CFD analyses are compared directly with thermocouple temperature measurements and with heat transfer coefficients on the rotor disc previously obtained from a rotor disc heat conduction solution. Considering the modelling limitations, the coupled approach predicted the solid metal temperatures well. Heat transfer coefficients on the rotor disc from CFD show some effect of the temperature variations on the heat transfer coefficients. Reasonable agreement is obtained with values deduced from the previous heat conduction solution.

scholarly journals Measurement of Internal Heat Transfer Distribution of Highly-Loaded Gas Turbine Blade by Combined Experimental/Numerical Method

2020 ◽  
Vol 197 ◽  
pp. 10007
Author(s):  
Asif Ali ◽  
Lorenzo Cocchi ◽  
Alessio Picchi ◽  
Bruno Facchini
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Gas Turbine ◽  
Cooling System ◽  
Internal Heat ◽  
Infrared Camera ◽  
External Temperature ◽  
Internally Cooled ◽  
Inlet Conditions ◽  
Internal Heat Transfer

To ensure a passable life span of gas turbine hot gas path components the measurement of metal surface temperature is paramount. Experimental analyses on internally cooled devices are often performed on simplified or scaled up geometries, which reduces the applicability of the results to the actual real hardware. A more reliable estimation of cooling performance could be obtained if the real engine component is directly studied. To achieve this goal, an experimental campaign is performed to investigate the internal heat transfer distribution of an industrial blade, cooled by means of an internal U-shaped channel. During the experiment the blade is heated to a known temperature, then a coolant is introduced through the internal channel to induce a thermal transient, during which the external surface temperature is measured with the help of an infrared camera. Then a transient thermal finite element simulation is performed with the same boundary and inlet conditions of the experiment. Based on the output of the simulation, the internal heat transfer distribution is updated until convergence between simulation output external temperature and the experimental temperature is achieved. In order to start the iterative procedure, a first attempt estimation of the internal heat transfer distribution is obtained with a lumped thermal capacitance model approach. Different experiments were performed with different mass flow rates and the results are compared with available literature data. The obtained results allow to observe detailed heat transfer phenomena, strongly bound to the relevant features of the actual real cooling system.

Heat Transfer Characteristics of a Blade Trailing Edge With Pressure Side Bleed Extraction

2013 ◽  
Author(s):  
H. Saxer-Felici ◽  
S. Naik ◽  
M. Gritsch
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Gas Turbine ◽  
Cooling System ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Transfer Coefficients ◽  
Trailing Edge ◽  
Heat Transfer Coefficients ◽  
The Impact

This paper investigates the heat transfer and pressure loss characteristic in the internal cooling system of the trailing edge of a gas turbine blade. The geometrical profile of the blade trailing edge and the operating conditions considered are representative of that normally found in a heavy-duty gas turbine. The trailing edge geometry consists of two radial passages with inclined turbulators which are connected with a bend. The trailing edge section consists of pins rows and a flow ejection cut-out slot. The impact of a cross-over hole in the web connecting the serpentine passages is also investigated. Both numerical and experimental studies were conducted at several passage Reynolds numbers ranging from 104 to 106. Experiments were conducted in a Perspex model at atmospheric conditions. The internal heat transfer coefficients were measured via the transient liquid crystal method and the pressure drop was measured via pressure taps. The impact of blade rotation on the heat transfer and pressure drop was also assessed numerically. Comparison of the measured and predicted heat transfer coefficients and pressure drops shows a good agreement for several flow conditions. The three-dimensional flow field in the passage and in the downstream pin banks was well captured numerically, with and without coolant injection via cross-over hole.

Comparison of a Conventional Thermal Analysis of a Turbine Cascade to a Full Conjugate Heat Transfer Computation

2008 ◽  
Author(s):  
Christoph Starke ◽  
Erik Janke ◽  
Toma´sˇ Hofer ◽  
Davide Lengani
Keyword(s):  
Heat Transfer ◽  
Boundary Condition ◽  
Conjugate Heat Transfer ◽  
Complex Geometry ◽  
Thermal Analyses ◽  
Turbine Cascade ◽  
Transfer Coefficients ◽  
Commercial Code ◽  
Blade Tip ◽  
Transfer Method

Recent development in commercial CFD codes offers possibilities to include the solid body in order to perform conjugate heat transfer computations for complex geometries. The current paper aims to analyse the differences between a conjugate heat transfer computation and conventional uncoupled approaches where a heat transfer coefficient is first derived from a flow solution and then taken as boundary condition for a thermal conduction analysis of the solid part. Whereas the thermal analyses are done with a Rolls-Royce in-house finite element code, the CFD as well as the conjugate heat transfer computation are done using the new version 8 of the commercial code Fine Turbo from Numeca International. The analysed geometry is a turbine cascade that was tested by VKI in Brussels within the European FP6 project AITEB 2. First, the paper presents the aerodynamic results. The pure flow solutions are validated against pressure measurements of the cascade test. Then, the heat transfer from flow computations with wall temperature boundary conditions is compared to the measured heat transfer. Once validated, the heat transfer coefficients are used as boundary condition for three uncoupled thermal analyses of the blade to predict its surface temperatures in a steady state. The results are then compared to a conjugate heat transfer method. Therefore, a mesh of the solid blade was added to the validated flow computation. The paper will present and compare the results of conventional uncoupled thermal analyses with different strategies for the wall boundary condition to results of a conjugate heat transfer computation. As it turns out, the global results are similar but especially the over-tip region with its complex geometry and flow structure and where effective cooling is crucial shows remarkable differences because the conjugate heat transfer solution predicts lower blade tip temperatures. This will be explained by the missing coupling between the fluid and the solid domain.

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