A Predictive Model for Preliminary Gas Turbine Blade Cooling Analysis

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Nafiz H. K. Chowdhury ◽  
Hootan Zirakzadeh ◽  
Je-Chin Han
Keyword(s):  
Heat Transfer ◽  
Boundary Conditions ◽  
Predictive Model ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Internal Boundary ◽  
Gas Turbine Blade ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Temperature Distributions

The growing trend to achieve a higher turbine inlet temperature (TIT) in the modern gas turbine industry requires a more efficient and advanced cooling system design. Therefore, a complete study of heat transfer is necessary to predict the thermal loadings on the gas turbine vanes and blades. In the current work, a predictive model for the gas turbine blade cooling analysis has been developed. The model is capable of calculating the distribution of coolant mass flow rate (MFR) and metal temperatures of a turbine blade using the mass and energy balance equations at given external and internal boundary conditions. Initially, the performance of the model is validated by demonstrating its capability to predict the temperature distributions for a NASA E3 blade. The model is capable of predicting the temperature distributions with reasonable accuracy, especially on the suction side (SS). Later, this paper documents the overall analysis for the same blade profile but at different boundary conditions to demonstrate the flexibility of the model for other cases. Additionally, guidelines are provided to obtain external heat transfer coefficient (HTC) distributions for the highly turbulent mainstream.

A Predictive Model for Preliminary Gas Turbine Blade Cooling Analysis

2015 ◽  
Author(s):  
Nafiz H. K. Chowdhury ◽  
Hootan Zirakzadeh ◽  
Je-Chin Han
Keyword(s):  
Heat Transfer ◽  
Boundary Conditions ◽  
Predictive Model ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Internal Boundary ◽  
Gas Turbine Blade ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Coupled Equations

The growing trend to achieve a higher Turbine Inlet Temperature (TIT) in the modern gas turbine industry requires, in return, a more efficient and advanced cooling system design. Therefore, a complete study of heat transfer is necessary to predict the thermal loadings in the turbine vane/blade. To estimate the metal temperatures, it is important to simulate the external hot gas flow condition, the conduction in the blade material, and the internal coolant flow characteristics accurately and simultaneously. As a result, proposing novel, quicker, and more convenient ways to study the heat transfer behavior of gas turbine blades is of absolute necessity. In the current work, a predictive model for the gas turbine blade cooling analysis in the form of a computer program has been developed to answer this need. The program is capable of estimating distribution of coolant mass flow rate, internal pressure and metal temperature of a turbine blade based on external and internal boundary conditions. The simultaneous solutions result from the coupled equations of mass and energy balance. The model is validated by showing its accuracy to predict the temperature distributions of a NASA E3 blade with an uncertainty of less than +/−10%. Later, this paper documents the overall analysis for a set of different boundary conditions with the same blade model (E3) and demonstrates the capability of the program to extend for other cases as well.

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.

Sign in / Sign up

Export Citation Format

Share Document