Thermal Investigation of Integrated Combustor Vane Concept Under Engine-Realistic Conditions

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Simon Jacobi ◽  
Budimir Rosic
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbines ◽  
High Speed ◽  
Secondary Flows ◽  
Experimental Measurements ◽  
Thermal Investigation ◽  
Nozzle Guide ◽  
The Heat Transfer Coefficient

This paper presents a thermal investigation of the integrated combustor vane concept for power generation gas turbines with individual can combustors. This concept has the potential to replace the high-pressure turbine’s first vanes by prolonged combustor walls. Experimental measurements are performed on a linear high-speed cascade consisting of two can combustors and two integrated vanes. The modularity of the facility allows for the testing at engine-realistic high turbulence levels, as well as swirl strengths with opposing swirl directions. The heat transfer characteristics of the integrated vanes are compared to conventional nozzle guide vanes. The experimental measurements are supported by detailed numerical simulations using the in-house computational fluid dynamics (CFD) code TBLOCK. Experimental as well as numerical results congruently indicate a considerable reduction of the heat transfer coefficient (HTC) on the integrated vanes surfaces and endwalls caused by a differing state of boundary layer thickness. The studies furthermore depict a slight, nondetrimental shift in the heat transfer coefficient distributions and the strength of the integrated vanes secondary flows as a result of engine-realistic combustor swirl.

Thermal Investigation of Integrated Combustor Vane Concept Under Engine-Realistic Conditions

2016 ◽  
Author(s):  
Simon Jacobi ◽  
Budimir Rosic
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbines ◽  
High Speed ◽  
Secondary Flows ◽  
Experimental Measurements ◽  
Thermal Investigation ◽  
Nozzle Guide ◽  
The Heat Transfer Coefficient

This paper presents a thermal investigation of the Integrated Combustor Vane concept for power generation gas turbines with individual can combustors. This concept has the potential to replace the high-pressure turbine’s first vanes by prolonged combustor walls. Experimental measurements are performed on a linear high-speed cascade consisting of two can combustors and two integrated vanes. The modularity of the facility allows for the testing at engine-realistic high turbulence levels, as well as swirl strengths with opposing swirl directions. The heat transfer characteristics of the integrated vanes are compared to conventional nozzle guide vanes. The experimental measurements are supported by detailed numerical simulations using the inhouse CFD code TBLOCK. Experimental as well as numerical results congruently indicate a considerable reduction of the heat transfer coefficient (HTC) on the integrated vanes surfaces and endwalls caused by a differing state of boundary layer thickness. The studies furthermore depict a slight, non-detrimental shift in the heat transfer coefficient distributions and the strength of the integrated vanes secondary flows as a result of engine-realistic combustor swirl.

Aerothermal Challenges in Syngas, Hydrogen-Fired, and Oxyfuel Turbines—Part I: Gas-Side Heat Transfer

2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Minking K. Chyu ◽  
Danny W. Mazzotta ◽  
Sean C. Siw ◽  
Ventzislav G. Karaivanov ◽  
William S. Slaughter ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Natural Gas ◽  
Transfer Coefficient ◽  
Gas Turbines ◽  
Computational Simulation ◽  
Department Of Energy ◽  
Working Fluid ◽  
Computational Fluid Dynamics Analysis ◽  
The Heat Transfer Coefficient

To meet the performance goals of advanced fossil power generation systems, future coal-gas fired turbines will likely be operated at temperatures higher than those in the current commercial natural gas-fired systems. The working fluid in these future turbines could contain substantial moisture (steam), mixed with carbon dioxide, instead of air or nitrogen in conventional gas turbines. As a result, the aerothermal characteristics among the advanced turbine systems are expected to be significantly different, not only from the natural gas turbines but also will be dependent strongly on the compositions of turbine working fluids. Described in this paper is a quantitative comparison of thermal load on the external surface of turbine airfoils that are projected to be utilized in different power cycles the U.S. Department of Energy plans for the next 2 decades. The study is pursued with a computational simulation, based on the three-dimensional computational fluid dynamics analysis. While the heat transfer coefficient has shown to vary strongly along the surface of the airfoil, the projected trends were relatively comparable for airfoils in syngas and hydrogen-fired cycles. However, the heat transfer coefficient for the oxyfuel cycle is found to be substantially higher by about 50–60% than its counterparts in syngas and hydrogen turbines. This is largely caused by the high steam concentration in the turbine flow. Results gained from this study overall suggest that advances in cooling technology and thermal barrier coatings are critical for developments of future coal-based turbine technologies with near zero emissions.

The Deformation Rule of the Cooled U75V Heavy Rail Caused by the Different Heat Transfer Coefficient

2011 ◽  
Vol 299-300 ◽  
pp. 1005-1011 ◽  
Author(s):  
Ming Xin Gao ◽  
Pei Long Wang ◽  
Hao Jia ◽  
Shan Hu Tong ◽  
Hua Song ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
High Speed ◽  
Reference Value ◽  
Ansys Software ◽  
Cooling Process ◽  
Technological Parameters ◽  
The Heat Transfer Coefficient ◽  
Heavy Rail

When rolled heavy rail is on the cooling bed for natural cooling, the heat transfer coefficient has important effect on the bending and section sizes of cooled heavy rail. In the paper, the heat-stress couple module ofANSYS software is adopted to carry on numerical simulation on the cooling process of 60kg/m U75V heavy rail, and we obtain the change rule that heat transfer coefficient has effect on bending curvature and section sizes of cooled heavy rail. This study is of great reference value on cooling bed design and the formulation of cooling technological parameters for high speed heavy rail.

Gas-Side Heat Transfer in Syngas, Hydrogen-Fired and Oxy-Fuel Turbines

2008 ◽  
Author(s):  
Danny W. Mazzotta ◽  
Ventzislav G. Karaivanov ◽  
Minking K. Chyu ◽  
William S. Slaughter ◽  
Mary Anne Alvin
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Natural Gas ◽  
Transfer Coefficient ◽  
Gas Turbines ◽  
Fuel Cycle ◽  
Computational Simulation ◽  
Department Of Energy ◽  
Working Fluid ◽  
The Heat Transfer Coefficient

To meet the performance goals of advanced fossil power generation systems; e.g. FutureGen, future coal-gas fired turbines will need to be operated at temperatures higher than those in the current commercial natural gas-fired systems. The working fluid in these future turbines could contain substantial moisture (steam) mixed with carbon dioxide, instead of air or nitrogen in conventional gas turbines. As a result, the aero-thermal characteristics among these new turbines are expected to be significantly different not only from the natural gas turbines but also dependent strongly on the compositions of turbine working fluids. Described in this paper is a quantitative comparison of thermal load on the external surface of turbine airfoil present in different power cycles the US Department of Energy plans for the next decade. The study is pursued with a computational simulation based on three-dimensional computational fluid dynamics (CFD) analysis. While the heat transfer coefficient has shown to vary strongly along the surface of the airfoil, the projected trends were relatively comparable for airfoils in syngas and hydrogen-fired cycles. However, the heat transfer coefficient for the oxy-fuel cycle is found to be substantially higher, by about 50–60%, than its counterparts in syngas and hydrogen turbines. This is largely attributable to the high steam concentration in the turbine flow. This overall suggests that advances in cooling technology and thermal barrier coatings are critical for the developments of future coal-based turbine technologies with nearly zero emission.

A new experimental approach for heat transfer coefficient and adiabatic wall temperature measurements on a Nozzle Guide Vane with inlet temperature distortions

2021 ◽  
pp. 1-33
Author(s):  
Tommaso Bacci ◽  
Alessio Picchi ◽  
Bruno Facchini ◽  
Simone Cubeda
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Wall Temperature ◽  
Gas Turbines ◽  
Experimental Approach ◽  
Guide Vane ◽  
Adiabatic Wall ◽  
Nozzle Guide Vane ◽  
Nozzle Guide

Abstract Modern gas turbines lean combustors are used to limit NOx pollutant emissions; on the other hand, their adoption presents other challenges, especially concerning the combustor-turbine interaction. Turbine inlet conditions are generally characterized by severe temperature distortions and swirl degree, which is responsible for very high turbulence intensities. Past studies have focused on the description of the effects of these phenomena on the behavior of the high pressure turbine. Nevertheless, very limited experimental results are available when it comes to evaluate the heat transfer coefficient (HTC) on the nozzle guide vane surface, since relevant temperature distortions present a severe challenge for the commonly adopted measurement techniques. The work presented in this paper was carried out on a non-reactive, annular, three-sector rig, made by a combustor simulator and a NGV cascade. It can reproduce a swirling flow, with temperature distortions at the combustor-turbine interface plane. This test apparatus was exploited to develop an experimental approach to retrieve heat transfer coefficient and adiabatic wall temperature distributions simultaneously, to overcome the known limitations imposed by temperature gradients on state-of-the-art methods for HTC calculation from transient tests. A non-cooled mockup of a NGV doublet, manufactured using low thermal diffusivity plastic material, was used for the tests, carried out using IR thermography with a transient approach. In the authors' knowledge, this presents the first experimental attempt of measuring a nozzle guide vane heat transfer coefficient in the presence of relevant temperature distortions and swirl.

High Resolution Heat Transfer Measurement on Flat and Contoured Endwalls in a Linear Cascade

2012 ◽  
Author(s):  
Benoit Laveau ◽  
Reza S. Abhari ◽  
Michael E. Crawford ◽  
Ewald Lutum
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Transfer Coefficient ◽  
High Resolution ◽  
Transfer Coefficient ◽  
Gas Turbines ◽  
Transfer Data ◽  
Numerical Predictions ◽  
Endwall Contouring ◽  
The Heat Transfer Coefficient

In order to continue increasing the efficiency of gas turbines, a significant effort is being made to reduce losses induced by secondary flows in turbine stages. In addition to their impact on aerodynamic losses, these vortical structures are also the source of large heat transfer variations across the passage. A substantial reduction of the secondary flow losses can be achieved with a contoured endwall. However, a change in the vortical pattern can dramatically impact the thermal loads on the endwall and lead to higher cooling requirements in those areas. This paper focuses on heat transfer measurements made in a passage with either flat or contoured endwalls. The experimental data are supplemented with numerical predictions of the heat transfer data. The measurements are carried out on an isothermal endwall equipped with symmetric NACA airfoils. The paper presents measurements at M = 0.3 corresponding to a Reynolds number ReCax = 4.6×105. An infrared camera is used to provide high-resolution surface temperature data on the endwall. The surface is equipped with an insulating layer (Kapton) allowing the calculation of heat flux through the endwall. The heat transfer quantities, namely the heat transfer coefficient and the adiabatic wall temperature, are then derived from a set of measurements at different isothermal plate temperatures. The numerical predictions clarify the link between the change in the heat transfer quantities and the changes in the flow field due to endwall contouring. Finally numerically predicted heat transfer data are deducted from a set of adiabatic and diabatic simulations that are compared to the experimental data. The comparison focuses on the differences in the regions with endwall contouring, where a significant difference in the heat transfer coefficient between flat and contoured endwalls is measured, but under-predicted numerically.

High Resolution Heat Transfer Measurement on Flat and Contoured Endwalls in a Linear Cascade

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Benoit Laveau ◽  
Reza S. Abhari ◽  
Michael E. Crawford ◽  
Ewald Lutum
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Transfer Coefficient ◽  
High Resolution ◽  
Transfer Coefficient ◽  
Gas Turbines ◽  
Transfer Data ◽  
Numerical Predictions ◽  
Endwall Contouring ◽  
The Heat Transfer Coefficient

In order to continue increasing the efficiency of gas turbines, a significant effort is being made to reduce losses induced by secondary flows in turbine stages. In addition to their impact on aerodynamic losses, these vortical structures are also the source of large heat transfer variations across the passage. A substantial reduction of the secondary flow losses can be achieved with a contoured endwall. However, a change in the vortical pattern can dramatically impact the thermal loads on the endwalls and lead to higher cooling requirements in those areas. This paper focuses on heat transfer measurements made in a passage with either flat or contoured endwalls. The experimental data are supplemented with numerical predictions of the heat transfer data. The measurements are carried out on an isothermal endwall equipped with symmetric airfoils. The paper presents measurements at M = 0.3, corresponding to a Reynolds number ReCax=4.6×105. An infrared camera is used to provide high-resolution surface temperature data on the endwall. The surface is equipped with an insulating layer (Kapton), allowing the calculation of heat flux through the endwall. The heat transfer quantities, namely the heat transfer coefficient and the adiabatic wall temperature, are then derived from a set of measurements at different isothermal plate temperatures. The numerical predictions clarify the link between the change in the heat transfer quantities and the changes in the flow field due to endwall contouring. Finally, numerically predicted heat transfer data are deduced from a set of adiabatic and diabatic simulations that are compared to the experimental data. The comparison focuses on the differences in the regions with endwall contouring, where a significant difference in the heat transfer coefficient between flat and contoured endwalls is measured but underpredicted numerically.

Turbine Blade Tip Heat Transfer in Low Speed and High Speed Flows

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Andrew P. S. Wheeler ◽  
Nicholas R. Atkins ◽  
Li He
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Heat Transfer Coefficient ◽  
Mach Number ◽  
Transfer Coefficient ◽  
High Speed ◽  
Low Speed ◽  
Blade Tip ◽  
The Heat Transfer Coefficient ◽  
Recovery Temperature

In this paper, high and low speed tip flows are investigated for a high-pressure turbine blade. Previous experimental data are used to validate a computational fluid dynamics (CFD) code, which is then used to study the tip heat transfer in high and low speed cascades. The results show that at engine representative Mach numbers, the tip flow is predominantly transonic. Thus, compared with the low speed tip flow, the heat transfer is affected by reductions in both the heat-transfer coefficient and the recovery temperature. The high Mach numbers in the tip region (M>1.5) lead to large local variations in recovery temperature. Significant changes in the heat-transfer coefficient are also observed. These are due to changes in the structure of the tip flow at high speed. At high speeds, the pressure side corner separation bubble reattachment occurs through supersonic acceleration, which halves the length of the bubble when the tip-gap exit Mach number is increased from 0.1 to 1.0. In addition, shock/boundary-layer interactions within the tip gap lead to large changes in the tip boundary-layer thickness. These effects give rise to significant differences in the heat-transfer coefficient within the tip region compared with the low speed tip flow. Compared with the low speed tip flow, the high speed tip flow is much less dominated by turbulent dissipation and is thus less sensitive to the choice of turbulence model. These results clearly demonstrate that blade tip heat transfer is a strong function of Mach number, an important implication when considering the use of low speed experimental testing and associated CFD validation in engine blade tip design.

Numerical Prediction of Turbulent Flow and Heat Transfer Within Ducts of Cross-Shaped Cross Section

1986 ◽  
Vol 108 (4) ◽  
pp. 841-847 ◽  
Author(s):  
A. Nakayama ◽  
H. Koyama
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Cross Section ◽  
Secondary Flows ◽  
Turbulent Heat Transfer ◽  
Parallel Plates ◽  
Reynolds Analogy ◽  
The Heat Transfer Coefficient ◽  
Shaped Cross Section

Calculations were carried out for fully developed turbulent flows within ducts of cross-shaped cross section using the numerical method based on the pressure correction method developed by Patankar and Spalding. The Reynolds stress driven secondary flows were simulated successfully by Launder and Ying’s algebraic stress model coupled to the k–ε turbulence model. A parametric study was made on the friction and heat transfer characteristics in terms of the parameter α associated with the decrease in the cross-sectional area, namely, α = 0 for a square duct, and α → 1 for infinite parallel plates. Through performance evaluations, it has been found that both the Reynolds analogy factor and the heat transfer coefficient under equal pumping power decrease slightly, while the heat transfer coefficient obtained with equal mass flow rate increases appreciably with α, suggesting effective turbulent heat transfer within ducts of cross-shaped cross section.

Impact of Wall Temperature on Heat Transfer Coefficient and Aerodynamics for Three-Dimensional Turbine Blade Passage

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
Roberto Maffulli ◽  
Li He
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Wall Temperature ◽  
Computational Study ◽  
Guide Vane ◽  
Three Dimensional ◽  
Correction Method ◽  
Secondary Flows ◽  
Nozzle Guide

The present work is aimed to examine how the heat transfer coefficient (HTC) and main three-dimensional (3D) passage aerodynamic features may be affected by a nonadiabatic wall temperature condition. A systematic computational study has been first carried out for a 3D nozzle guide vane (NGV) passage. The impacts of wall temperature on the secondary flows, trailing edge shock waves, and the passage flow capacity are discussed, underlining the connection and interactions between the wall temperature and the external aerodynamics of the 3D passage. The local discrepancies in HTC in these 3D flow regions can be as high as 30–40% when comparing low and high temperature ratio cases. The effort is then directed to a new three-point nonlinear correction method. The benefit of the three-point method in reducing errors in HTC is clearly demonstrated. A further study illustrates that the new method also offers much enhanced robustness in the wall heat flux scaling, particularly relevant when the wall thermal condition is also shown to influence the laminar–turbulent transition exhibited by two well-established transition models adopted in the present work.

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