Evaluation of FEM Based Methods to Predict Temperature Distributions of a Convection Cooled Gas Turbine Blade

2014 ◽  
Author(s):  
B. Woerz ◽  
Y. Mick ◽  
E. Findeisen ◽  
P. Jeschke ◽  
M. Rabs
Keyword(s):  
Heat Transfer ◽  
Numerical Methods ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Gas Turbines ◽  
Cooling System ◽  
Three Dimensional ◽  
Gas Turbine Blade ◽  
Cooling Channels ◽  
Hot Gas

This paper presents 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 which is equipped with a state-of-the-art convection cooling system. Firstly, two FEM based methods are introduced. One method, referred to as FEM1D method, uses empirical correlations from the open literature to obtain one dimensional heat transfer coefficients along one flow line inside the cooling channels while in the hot gas path a three dimensional CFD simulation is used. The second method (FEM2D) uses three dimensional CFD simulations to obtain two dimensional heat transfer coefficient distributions for both, the inner cooling channels and the hot gas path. The results from both numerical methods are compared with each other and are validated with experimental data, quantifying also their accuracy limits. In total this paper gives an evaluation of two different FEM methods to predict temperature distribution in convection cooled gas turbines. Their accuracy, numerical cost and limitations are evaluated. It turns out that the temperature profiles gained by both methods are generally in good agreement with the experiments. However, while causing higher numerical costs the more detailed FEM2D method achieves more accurate results.

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.

Heat Transfer in Leading Edge, Triangular Shaped Cooling Channels With Angled Ribs Under High Rotation Numbers

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Yao-Hsien Liu ◽  
Michael Huh ◽  
Dong-Ho Rhee ◽  
Je-Chin Han ◽  
Hee-Koo Moon
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Rotation Number ◽  
Leading Edge ◽  
Gas Turbine Blade ◽  
Cooling Channels ◽  
Triangular Channel ◽  
Buoyancy Parameter ◽  
Rotation Numbers

The gas turbine blade/vane internal cooling is achieved by circulating compressed air through the cooling channels inside the turbine blade. Cooling channel geometries vary to fit the blade profile. This paper experimentally investigated the rotational effects on heat transfer in an equilateral triangular channel (Dh=1.83 cm). The triangular shaped channel is applicable to the leading edge of the gas turbine blade. Angled 45 deg ribs are placed on the leading and trailing surfaces of the test section to enhance heat transfer. The rib pitch-to-rib height ratio (P/e) is 8 and the rib height-to-channel hydraulic diameter ratio (e/Dh) is 0.087. Effect of the angled ribs under high rotation numbers and buoyancy parameters is also presented. Results show that due to the radially outward flow, heat transfer is enhanced with rotation on the trailing surface. By varying the Reynolds numbers (10,000–40,000) and the rotational speeds (0–400 rpm), the rotation number and buoyancy parameter reached in this study are 0–0.58 and 0–1.9, respectively. The higher rotation number and buoyancy parameter correlate very well and can be used to predict the rotational heat transfer in the equilateral triangular channel.

Rotating Effects on Heat Transfer Rate in a Cooling Air Passage of a Gas Turbine Blade

2004 ◽  
Author(s):  
Fernando Z. Sierra ◽  
Juan C. Garci´a ◽  
Janusz Kubiak ◽  
Gustavo Urquiza
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Heat Transfer Rate ◽  
Turbine Blade ◽  
Rotation Rate ◽  
Gas Turbines ◽  
Transfer Rate ◽  
Gas Turbine Blade ◽  
Air Passage ◽  
Cooling Air

In this paper numerical results on the effects of rotation on heat transfer rates in a cooling air passage that belongs to a gas turbine blade are presented. A 180° turn about has been considered into the computations. Rotation rates of 1145, 2800 and 3600 rpm were considered into the analysis. Comparisons for a Re = 53 000 with literature published results showed a good agreement. The simulation has been based on the finite volume approach of a 3-D flow using a second moment closure model for modeling the turbulence in the air passage. The results indicate that the rotation rate produces important changes in the heat transfer rate. In this work heat transfer has been characterized through the Nusselt number, along the air flowing path. A rotation rate of 3600 rpm produces an increment of the heat transfer rate by 14% along the inlet edge of the blade compared with the condition of no rotation. However, a decrease of 16.7% is observed in the outlet edge under the same conditions, compared against the non rotating condition. The situation is drastic in the tip region of the blade where more than 18.5% higher heating rate is observed for the same rotating speed. These results correspond to the outer internal wall of the blade passage, while the situation for the inner wall are in general less severe. The velocity field shows the formation of several secondary cells of flow which may represent stagnation regions for both pressure and heat transfer. These secondary cells are observed mainly in the region of the turn of 180°. The dynamics of these cells are important for the performance and design of the cooling system in gas turbines.

A new conjugate heat transfer method to analyse a 3D steam cooled gas turbine blade with temperature-dependent material properties

2011 ◽  
Vol 226 (5) ◽  
pp. 1309-1320 ◽  
Author(s):  
M M Jafari ◽  
G Atefi ◽  
J Khalesi ◽  
A Soleymani
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Power Plants ◽  
Conjugate Heat Transfer ◽  
Three Dimensional ◽  
Computer Code ◽  
Gas Turbine Blade ◽  
Temperature Dependent ◽  
Transfer Method

The erosion of the hot regions in a gas turbine is one of the most important challenges encountered by the power plants. Though several numerical simulations of the problem have been reported so far, little is known to give accurate results. In this article, the thermoelastic behaviour of a gas turbine blade with internal steam-cooled channels positioned within a three-dimensional cascade configuration has been studied. A computer code based on the conjugate heat transfer method using the simultaneous solution of Navier–Stokes and heat transfer equations has been developed. From this study, the temperature distribution along with the stress values at high temperatures has been obtained. The blade parameters such as E, α, and K were considered to be a function of the temperature. In the previous works, usually only one or two of these parameters was considered as temperature dependent and the others constant. In this article, all the blade parameters, though making the equations highly non-linear, were considered as a function of temperature. The results have been compared with the available experimental data and a good agreement is observed. According to these findings, taking the temperature dependency of materials into account increases the estimations accuracy and brings the results closer to the reality.

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.

Heat Transfer in Leading Edge, Triangular Shaped Cooling Channels With Angled Ribs Under High Rotation Numbers

2008 ◽  
Author(s):  
Yao-Hsien Liu ◽  
Michael Huh ◽  
Dong-Ho Rhee ◽  
Je-Chin Han ◽  
Hee-Koo Moon
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Rotation Number ◽  
Leading Edge ◽  
Gas Turbine Blade ◽  
Cooling Channels ◽  
Triangular Channel ◽  
Buoyancy Parameter ◽  
Rotation Numbers

The gas turbine blade/vane internal cooling is achieved by circulating the compressed air through the cooling channels inside the turbine blade. Cooling channel geometries vary to fit the blade profile. This paper experimentally investigated the rotational effects on heat transfer in an equilateral triangular channel (Dh = 1.83cm). The triangular shaped channel is applicable to the leading edge of the gas turbine blade. 45° angled ribs are put on the leading and trailing surfaces of the test section to enhance heat transfer. The rib pitch-to-height ratio (P/e) is 8 and the height-to-hydraulic diameter ratio (e/Dh) is 0.087. Effect of the angled ribs under high rotation numbers and buoyancy parameters are also presented. Results show that due to the radially outward flow, heat transfer is enhanced with rotation on the trailing surface. By varying the Reynolds numbers (10000–40000) and the rotational speeds (0–400 rpm), the rotation number and buoyancy parameter reached in this study are 0–0.58 and 0–1.9, respectively. The higher rotation number and buoyancy parameter have been correlated very well to predict the rotational heat transfer in the equilateral triangular channel.

scholarly journals Performance prediction of trailing-edge cooling system of gas turbine blade using detached eddy simulation

2020 ◽  
Vol 1 (1) ◽  
pp. 16-21
Author(s):  
Agus Jamaldi ◽  
Hassan Khamis Hassan
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Cooling System ◽  
Computational Domain ◽  
Gas Turbine Blade ◽  
Trailing Edge ◽  
Blowing Ratio ◽  
Eddy Simulation ◽  
Pin Fins

This study aims to evaluate the performance of the trailing-edge (TE) cooling system in a gas turbine blade. Eddy Simulation (DES), based on the turbulence model of Spallart-Almaras (SA), was used to simulate the TE cooling system. A TE configuration with a five-row staggered pin-fin arrangement was employed as a computational domain. Three parameters, i.e., the coefficient of heat transfer on the pin-fins surface (hpin), the coefficient of discharge (CD), and the effectiveness of adiabatic film cooling were used to assess the performances. The findings denoted that the heat transfer fluctuations occurred on the surface of the pin-fins in each row. The discharge coefficient increased with the rising of the blowing ratio. The trend predicted data of effectiveness were in good agreement with realistic discrepancies compared to other researches, mainly for higher blowing ratio. The average effectiveness along the cut-off region was to be sensitive to the changes of the blowing ratio, which was attributed to the structures of turbulent flow along the mixing region.

Effects of Boot-Shaped Rib On Heat Transfer Characteristics of Internal Cooling Turbine Blades

2020 ◽  
Author(s):  
Ky-Quang Pham ◽  
Quang-Hai Nguyen ◽  
Tai-Duy Vu ◽  
Cong-Truong Dinh
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Cooling System ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Wall Friction ◽  
Inlet Temperature ◽  
Internal Cooling ◽  
Toe Angle

Abstract Gas turbine engine has been widely applied to many heavy industries, such as marine propulsion and aerospace fields. Increasing turbine inlet temperature is one of the major ways to improve the thermal efficiency of gas turbines. Internal cooling for gas turbine cooling system is one of the most commonly used approaches to reduce the temperature of blades by casting various kinds of ribs in serpentine passages to enhance the heat transfer between the coolant and hot surface of gas turbine blades. This paper presents an investigation of boot-shaped rib design to increase the heat transfer performances in the internal cooling turbine blades for gas turbine engines. By varying the design parameter configuration, the airflow is taken with higher momentum, and the minor vortex being at the front rib is relatively removed. The object of this investigation is increasing the reattachment airflow to wall and reducing the vortex occurring near the rib for improving the performances of heat transfer using three-dimensional Reynolds-averaged Navier-Stokes with the SST model. A parametric study of the boot-shaped rib design was performed using various geometric parameters related to the heel-angle, toe-angle, slope-height and rib-width to find their effect on the Nusselt number, temperature on the ribbed wall, friction factor ratio of the channel and thermal performance factor. The numerical results showed that the heat transfer performances are significantly increased with the heel-angle, toe-angle, slope-height, while that remained relatively constant with the rib-width.

Novel Technology for Gas Turbine Blade Effusion Cooling

2006 ◽  
Author(s):  
Lorenzo Battisti ◽  
Roberto Fedrizzi ◽  
Giovanni Cerri
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Film Cooling ◽  
Gas Turbines ◽  
Cooling System ◽  
Turbine Blades ◽  
Innovative Technology ◽  
Gas Turbine Blade ◽  
Combustion Chambers ◽  
Reliable Technique

Gas turbine combustion chambers and turbine blades require better cooling techniques to cope with the increase in operating temperatures with each new engine model. Current gas turbine inlet temperatures are approaching 2000 K. Such extreme temperatures, combined with a highly dynamic environment, result in major stress on components, especially combustion chamber and blades of the first turbine stages. A technique that has been extensively investigated is transpiration cooling, for both combustion chambers and turbine blades. Transpiration-cooled components have proved an effective way to achieve high temperatures and erosion resistance for gas turbines operating in aggressive environments, though there is a shortage of durable and proven technical solutions. Effusion cooling (full-coverage discrete hole film cooling), on the other hand, is a relatively simpler and more reliable technique offering a continuous coverage of cooling air over the component’s hot surfaces. This paper presents an innovative technology for the efficient effusion cooling of the combustor wall and turbine blades. The dedicated electroforming process used to manufacture effusive film cooling systems, called Poroform®, is illustrated. A numerical model is also presented, developed specifically for designing the distributions of the diameter and density of the holes on the cooled surface with a view to reducing the metal’s working temperature and achieving isothermal conditions for large blade areas. Numerical simulations were used to design the effusive cooling system for a first-stage gas turbine blade. The diameter, density and spacing of the holes, and the adiabatic film efficiency are discussed extensively to highlight the cooling capacity of the effusive system.

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