Flow and Heat Transfer Analysis of Turbine Blade Cooling Passages Using Network Method

2012 ◽  
Author(s):  
Mohammad Alizadeh ◽  
Ali Izadi ◽  
Alireza Fathi ◽  
Hiwa Khaledi
Keyword(s):  
Heat Transfer ◽  
Boundary Conditions ◽  
Turbine Blade ◽  
Numerical Data ◽  
Internal Cooling ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Flow And Heat Transfer ◽  
Network Method ◽  
Cooling Passage

Modern turbine blades are cooled by air flowing through internal cooling passages. Three-Dimensional numerical simulation of these blade cooling passages is too time-consuming because of their complex geometries. These geometrical complexities exist as a result of using various kinds of cooling technologies such as rib turbulators (inline, staggered, or inclined ribs), pin fin, 90 and 180 degree turns (both sharp and gradual turns, with and without turbulators), finned passage, by-pass flow and tip cap impingement. One possible solution to simulate such sophisticated passages is to use the one-dimensional network method, which is presented in the current work. Turbine blade cooling channels are flow passages having multiple inlets and exits. The present in-house developed solver uses a network method for analyzing such a complicated flow pattern. In this method, cooling system is represented by a network of elements connected together at different nodes. Using assumed wall temperature, internal flow and heat transfer is calculated. The final goal of this computation is a set of boundary conditions for conjugate blade heat transfer simulation (coolant side boundary conditions). For validation, it is required to use experimental data that include temperature distribution of blade coolant-side walls. Since there is no experimental work with such data in the open literature, numerical computation is validated using available analytical and published numerical data. Calculated results agree well with analytical and numerical data. In order to exhibit the potential capabilities of the developed code, flow and heat transfer in a complicated internal cooling passage of a typical vane are investigated using the network method.

scholarly journals A Computational Visualization of Three Dimensional Flow: Finding Optimum Heat Transfer and Pressure Drop Characteristics From Short Cross-Pin Arrays and Comparison With Two Dimensional Calculations

1999 ◽  
Author(s):  
E. E. Donahoo ◽  
C. Camci ◽  
A. K. Kulkarni ◽  
A. D. Belegundu
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Structural Integrity ◽  
Turbine Blades ◽  
Circular Cross Section ◽  
Internal Cooling ◽  
Flow And Heat Transfer ◽  
High Heat Transfer ◽  
Spacing Ratio ◽  
Cooling Passage

There are many heat transfer augmentation methods that are employed in turbine blade design, such as impingement cooling, film cooling, serpentine passages, trip strips, vortex chambers, and pin fins. The use of crosspins in the trailing edge section of turbine blades is commonly a viable option due to their ability to promote turbulence as well as supply structural integrity and stiffness to the blade itself. Numerous crosspin shapes and arrangements are possible, but only certain configurations offer high heat transfer capability while maintaining taw total pressure loss. This study preseots results from 3-D numerical simulations of airflow through a turbine blade internal cooling passage. The simulations model viscous flow and heat transfer over full crosspins of circular cross-section with fixed height-to-diameter ratio of 0.5, fixed transverse-to-diameter spacing ratio of 1.5, and varying streamwise spacing. Preliminary analysis indicates that endwall effects dominate the flow and heat transfer at lower Reynolds numbers. The flow dynamics involved with the relative dose proximity of the endwalls for such short crosspins have a definite influeoce on crosspin efficiency for downstream rows.

Numerical Analysis of Fluid Flow in an Internal Turbine Blade Cooling Passage

1995 ◽  
Author(s):  
Marc L. Babich ◽  
Song-Lin Yang ◽  
Donna J. Michalek ◽  
Oner Arici
Keyword(s):  
Turbine Blade ◽  
High Efficiency ◽  
Stokes Equations ◽  
Numerical Study ◽  
Inlet Temperature ◽  
Internal Cooling ◽  
Grid Turbulence ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Cooling Passage

The need to develop ultra-high efficiency turbines demands the exploration of methods which will improve the thermal efficiency and the specific thrust of the engine. One means of achieving these goals is to increase the turbine inlet temperature. In order to accomplish this, further advances in turbine blade cooling technology will have to be realized. A technique which has only recently been used in the analysis of turbine blade cooling is computational fluid dynamics. The purpose of this paper is to present a numerical study of the flowfield inside of the internal cooling passage of a radial turbine blade. The passage is modeled as two-dimensional and non-rotating. The flowfield solutions are obtained using a pseudo-compressible formulation of the Navier-Stokes equations. The spatial discretization is performed using a symmetric second-order accurate TVD (Total Variational Diminishing) scheme. Calculations are performed on a multi-block-structured grid. Turbulence is modeled using a modified κ-ω model. In the absence of experimental data, results appear to be realistic based on common experiences with fluid mechanics.

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.

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.

Experimental Study of Heat Transfer Augmentation Near the Entrance to a Film Cooling Hole in a Turbine Blade Cooling Passage

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Gerard Scheepers ◽  
R. M. Morris
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Turbine Blade ◽  
Film Cooling ◽  
Surface Heat ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Heat Transfer Augmentation ◽  
Cooling Hole ◽  
Cooling Passage

Film cooling is extensively used by modern gas turbine blade designers as a means of limiting the blade temperature when exposed to extreme combustor outlet temperatures. The following paper describes an experimental study of heat transfer near the entrance to a film cooling hole in a turbine blade cooling passage. Steady state heat transfer results were acquired by using a transient measurement technique in a 40 times actual rectangular channel, representative of an internal cooling channel of a turbine blade. Platinum thin film gauges were used to measure the inner surface heat transfer augmentation as a result of thermal boundary layer renewal and impingement near the entrance of a film cooling hole. Measurements were taken at various suction ratios, extraction angles, and wall temperature ratios with a main duct Reynolds number of 25,000. A numerical technique based on the resolution of the unsteady conduction equation, using a Crank–Nicholson scheme, is used to obtain the surface heat flux from the measured surface temperature history. Computational fluid dynamics predictions were also made to provide better understanding of the near-hole flow. The results show extensive heat transfer enhancement as a function of extraction angle and suction ratio in the near-hole region and demonstrate good agreement with a corresponding study. Furthermore it was shown that the effect of a wall-to-coolant ratio is of a second order and can therefore be considered negligible compared with the primary variables such as the suction ratio and extraction angle.o

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