scholarly journals Numerical Investigation of a Radially Cooled Turbine Guide Vane Using Air and Steam as a Cooling Medium

Computation ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 63
Author(s):  
Sondre Norheim ◽  
Shokri Amzin
Keyword(s):  
Numerical Model ◽  
Gas Turbines ◽  
Guide Vane ◽  
Axial Direction ◽  
Average Error ◽  
Inlet Temperature ◽  
Average Temperature ◽  
Cooling Medium ◽  
Turbine Guide Vane ◽  
Steam Cooling

Gas turbine performance is closely linked to the turbine inlet temperature, which is limited by the turbine guide vanes ability to withstand the massive thermal loads. Thus, steam cooling has been introduced as an advanced cooling technology to improve the efficiency of modern high-temperature gas turbines. This study compares the cooling performance of compressed air and steam in the renowned radially cooled NASA C3X turbine guide vane, using a numerical model. The conjugate heat transfer (CHT) model is based on the RANS-method, where the shear stress transport (SST) k−ω model is selected to predict the effects of turbulence. The numerical model is validated against experimental pressure and temperature distributions at the external surface of the vane. The results are in good agreement with the experimental data, with an average error of 1.39% and 3.78%, respectively. By comparing the two coolants, steam is confirmed as the superior cooling medium. The disparity between the coolants increases along the axial direction of the vane, and the total volume average temperature difference is 30 K. Further investigations are recommended to deal with the local hot-spots located near the leading- and trailing edge of the vane.

Experimental and Numerical Conjugate Investigation of the Blowing-Ratio Influence on the Showerhead Cooling Efficiency

1998 ◽  
Author(s):  
Dieter E. Bohn ◽  
Volker J. Becker ◽  
Karsten A. Kusterer ◽  
Agnes U. Rungen
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Guide Vane ◽  
Leading Edge ◽  
Suction Side ◽  
Computer Code ◽  
Inlet Temperature ◽  
Cooling Efficiency ◽  
Blowing Ratio ◽  
Turbine Guide Vane

This paper presents the experimental investigation of the flow and the numerical analysis of the flow and heat transfer in a turbine guide vane with showerhead cooling for two different blowing ratios. The aerodynamic results are compared with those of the experiments. Starting with a showerhead design of two rows of ejection holes, two additional rows have to be used in an enhanced design due to hot gas contact in the leading edge area. Thus, the cooling gas mass flow is doubled when keeping the blowing ratio constant at m = 1.5. Lowering the amount of cooling gas needed whilst still guaranteeing sufficient cooling is the motivation for the analysis of the influence of a lower blowing ratio on the cooling efficiency. The investigated blowing ratios are m = 1.5 and m = 1.0. The experiments are conducted using a non-intrusive LDA technique. The numerical results are gained with a conjugate heat transfer and flow computer code that has been developed at the Institute of Steam and Gas Turbines. The results show that the blowing ratio has to be chosen carefully as the leading edge flow pattern and the heat transfer are strongly influenced by the blowing ratio. Lower blowing ratios lead to a better attachment of the cooling film and thus they hardly disturb the main flow. With the lower blowing ratio, the material temperature increases up to 1.5% of the total inlet temperature in the leading edge area on the pressure side, whereas it decreases locally for about 0.8% for the lower blowing ratio on the suction side. This is due to the enhanced attachment of the cooling gas film.

A Conjugate 3-D Flow and Heat Transfer Analysis of a Thermal Barrier Cooled Turbine Guide Vane

1998 ◽  
Author(s):  
Dieter E. Bohn ◽  
Volker J. Becker
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Guide Vane ◽  
Suction Side ◽  
Heat Transfer Analysis ◽  
Thermal Barrier ◽  
Trailing Edge ◽  
Flow And Heat Transfer ◽  
Turbine Guide Vane ◽  
Basic Configuration

This paper presents the numerical investigations of the flow and heat transfer of two configurations of a transonic turbine guide vane. The basic configuration is a vane with convection cooling. The second configuration is additionally coated with a thermal barrier consisting of ZrO2. The results are obtained with a conjugate heat transfer and flow computer code that has been developed at the Institute of Steam and Gas Turbines. Measurement data is available for the basic configuration and the computational results are compared to the experimental results. The results show very good agreement between calculated and measured vane surface temperatures. The trailing edge turns out to be subjected to high thermal loads as it is too thin to be cooled effectively. Secondary flow phenomena like the passage vortex and the corner vortex and their impact on the temperature distribution are discussed. The ZrO2 coating is calculated for a thickness of 300μm. The substrate material temperatures are lowered by about 20 K–29 K in the stagnation point area and by about 27 K–43 K in the shock area on the suction side. At the trailing edge, the coating on the suction side and on the pressure side hardly influences the metal temperature.

Off-design performance improvement of twin-shaft gas turbine by variable geometry turbine and compressor besides fuel control

2019 ◽  
Vol 234 (7) ◽  
pp. 957-980
Author(s):  
Sepehr Sanaye ◽  
Salahadin Hosseini
Keyword(s):  
Life Cycle ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Guide Vane ◽  
Design Parameters ◽  
Inlet Guide Vane ◽  
Inlet Temperature ◽  
Gas Generator ◽  
Turbine Inlet ◽  
Exit Temperature

A novel procedure for finding the optimum values of design parameters of industrial twin-shaft gas turbines at various ambient temperatures is presented here. This paper focuses on being off design due to various ambient temperatures. The gas turbine modeling is performed by applying compressor and turbine characteristic maps and using thermodynamic matching method. The gas turbine power output is selected as an objective function in optimization procedure with genetic algorithm. Design parameters are compressor inlet guide vane angle, turbine exit temperature, and power turbine inlet nozzle guide vane angle. The novel constrains in optimization are compressor surge margin and turbine blade life cycle. A trained neural network is used for life cycle estimation of high pressure (gas generator) turbine blades. Results for optimum values for nozzle guide vane/inlet guide vane (23°/27°–27°/6°) in ambient temperature range of 25–45 ℃ provided higher net power output (3–4.3%) and more secured compressor surge margin in comparison with that for gas turbines control by turbine exit temperature. Gas turbines thermal efficiency also increased from 0.09 to 0.34% (while the gas generator turbine first rotor blade creep life cycle was kept almost constant about 40,000 h). Meanwhile, the averaged values for turbine exit temperature/turbine inlet temperature changed from 831.2/1475 to 823/1471°K, respectively, which shows about 1% decrease in turbine exit temperature and 0.3% decrease in turbine inlet temperature.

scholarly journals Numerical Investigation of Influence of Entropy Wave on the Acoustic and Wall Heat Transfer Characteristics of a High-Pressure Turbine Guide Vane

Acoustics ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 524-538
Author(s):  
Keqi Hu ◽  
Yuanqi Fang ◽  
Yao Zheng ◽  
Gaofeng Wang ◽  
Stéphane Moreau
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Flow Field ◽  
Transfer Coefficient ◽  
Gas Turbines ◽  
Guide Vane ◽  
Turbulence Models ◽  
Local Pressure ◽  
Maximum Heat ◽  
Turbine Guide Vane

As an indirect noise source generated in the combustion chamber, entropy waves are widely prevalent in modern gas turbines and aero-engines. In the present work, the influence of entropy waves on the downstream flow field of a turbine guide vane is investigated. The work is mainly based on a well-known experimental configuration called LS89. Two different turbulence models are used in the simulations which are the standard k-ω model and the scale-adaptive simulation (SAS) model. In order to handle the potential transition issue, Menter’s ð-Reθ transition model is coupled with both models. The baseline cases are first simulated with the two different turbulence models without any incoming perturbation. Then one forced case with an entropy wave train set at the turbine inlet at a given frequency and amplitude is simulated. Results show that the downstream maximum Mach number is rising from 0.98 to 1.16, because the entropy waves increase the local temperature of the flow field; also, the torque of the vane varies as the entropy waves go through, the magnitude of the oscillation is 7% of the unforced case. For the wall (both suction and pressure side of the vane) heat transfer, the entropy waves make the maximum heat transfer coefficient nearly twice as the large at the leading edge, while the minimum heat transfer coefficient stays at a low level. As for the averaged normalized heat transfer coefficient, a maximum difference of 30% appears between the baseline case and the forced case. Besides, during the transmission process of entropy waves, the local pressure fluctuates with the wake vortex shedding. The oscillation magnitude of the pressure wave at the throat is found to be enhanced due to the inlet entropy wave by applying the dynamic mode decomposition (DMD) method. Moreover, the transmission coefficient of the entropy waves, and the reflection and transmission coefficients of acoustic waves are calculated.

Development of an Air Cooled G Class Gas Turbine (the M501GAC)

2009 ◽  
Author(s):  
Toshishige Ai ◽  
Carlos Koeneke ◽  
Hisato Arimura ◽  
Yoshinori Hyakutake
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Inlet Temperature ◽  
Air Cooling ◽  
National Project ◽  
Commercial Operation ◽  
Steam Cooling ◽  
Verification Test ◽  
Verification Process ◽  
Verification Plan

Mitsubishi Heavy Industries (MHI) G series gas turbine is the industry pioneer in introducing steam cooling technology for gas turbines. The first M501G unit started commercial operation in 1997 and to date, with 62 G units sold, MHI G fleet is the largest steam cooled fleet in the market. The existing commercial fleet includes 35 commercial units with more than 734,000 accumulated actual operating hours, and over 9,400 starts. Upgraded versions have been introduced in the 60 and 50Hz markets (M501G1 and M701G2 respectively). On a different arena, MHI is engaged since 2004 in a Japanese National Project for the development of 1,700°C (3092°F) class gas turbine. Several enhanced technologies developed through this Japanese National Project, including lower thermal conductivity TBC, are being retrofitted to the existing F and G series gas turbines. Retrofitting some of these technologies to the existing M501G1 together with the application of an F class air cooled combustion system will result in an upgraded air-cooled G class engine with increased power output and enhanced efficiency, while maintaining the same 1500°C (2732°F) Turbine Inlet Temperature (TIT). By using an open air cooling scheme, this upgraded machine represents a better match for highly cyclic applications with G class efficiency, while the highly reliable and durable steam cooled counterpart is still offered for more base-loaded applications. After performing various R&D tests, the verification process of the air cooled 60 Hz G gas turbine has moved to component testing in the in-house verification engine. The final verification test prior to commercial operation is scheduled for 2009. This article describes the design features and verification plan of the upgraded M501G gas turbine.

Effects of inlet turbulence intensity on wall heat transfer in a turbine guide vane

2020 ◽  
Vol 34 (14n16) ◽  
pp. 2040082
Author(s):  
Ke-Qi Hu ◽  
Yi-Fan Xia ◽  
Yao Zheng ◽  
Gao-Feng Wang
Keyword(s):  
Heat Transfer ◽  
Turbulence Intensity ◽  
Gas Turbines ◽  
Guide Vane ◽  
Turbulence Models ◽  
Suction Side ◽  
Industrial Applications ◽  
Wall Heat Transfer ◽  
Turbine Guide Vane ◽  
Sas Model

Heat transfer is an important phenomenon that exists in many industrial applications, especially for gas turbines, aeronautical engines. In this work, two different turbulence models ([Formula: see text] and SAS model) are used to investigate the effects of inlet turbulence on wall heat transfer and the characteristics of flow field in a well-known turbine guide vane (LS89). In order to handle the transition, Menter’s [Formula: see text] transition model is used. The simulations show that the inlet turbulence has an apparent effect on the wall heat transfer of the vane. Not only the maximum wall heat transfer coefficient is increased, the distribution of wall heat flux at the suction side is also modified. The isentropic Mach number along the vane surface is insensitive to the variance of inlet turbulence intensity. Besides, a shock appears in the throat and a laminar-to-turbulence transition position moves forward after the main flow turbulence is enhanced. Moreover, the results indicate that SAS model is capable of capturing more flow structures such as reflecting pressure waves and shedding vortexes while the [Formula: see text] model misses them due to the dissipation.

Simulations of Multiphase Particle Deposition on a Showerhead With Staggered Film-Cooling Holes

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Seth A. Lawson ◽  
Karen A. Thole ◽  
Yoji Okita ◽  
Chiyuki Nakamata
Keyword(s):  
Gas Turbines ◽  
Particle Deposition ◽  
Large Scale ◽  
Guide Vane ◽  
Particle Temperature ◽  
Sand Particle ◽  
Inlet Temperature ◽  
Cooling Effectiveness ◽  
Turbine Cooling ◽  
Blowing Ratio

The demand for cleaner, more efficient energy has driven the motivation for improving the performance standards for gas turbines. Increasing the combustion temperature is one way to get the best possible performance from a gas turbine. One problem associated with increased combustion temperatures is that particles ingested in the fuel and air become more prone to deposition with an increase in turbine inlet temperature. Deposition on aero-engine turbine components caused by sand particle ingestion can impair turbine cooling methods and lead to reduced component life. It is necessary to understand the extent to which particle deposition affects turbine cooling in the leading edge region of the nozzle guide vane where intricate showerhead cooling geometries are utilized. For the current study, wax was used to dynamically simulate multiphase particle deposition on a large scale showerhead cooling geometry. The effects of deposition development, coolant blowing ratio, and particle temperature were tested. Infrared thermography was used to quantify the effects of deposition on cooling effectiveness. Although deposition decreased with an increase in coolant blowing ratio, results showed that reductions in cooling effectiveness caused by deposition increased with an increase in blowing ratio. Results also showed that effectiveness reduction increased with an increase in particle temperature. Reductions in cooling effectiveness reached as high as 36% at M = 1.0.

Aerodynamic Performance of a Transonic Turbine Guide Vane With Trailing Edge Coolant Ejection: Part I—Experimental Approach

1996 ◽  
Vol 118 (3) ◽  
pp. 519-528 ◽  
Author(s):  
C. Kapteijn ◽  
J. Amecke ◽  
V. Michelassi
Keyword(s):  
Gas Turbines ◽  
Experimental Approach ◽  
Guide Vane ◽  
Flow Behavior ◽  
Aerodynamic Performance ◽  
Inlet Guide Vane ◽  
Trailing Edge ◽  
Cooling Flow ◽  
Turbine Guide Vane ◽  
Transonic Turbine

Inlet guide vanes (IGV) of high-temperature gas turbines require an effective trailing edge cooling. But this cooling significantly influences the aerodynamic performance caused by the unavoidable thickening of the trailing edge and the interference of the cooling flow with the main flow. As part of a comprehensive research program, an inlet guide vane was designed and manufactured with two different trailing edge shapes. The results from the cascade tests show that the flow behavior upstream of the trailing edge remains unchanged. The homogeneous values downstream show higher turning and higher losses for the cut-back blade, especially in the supersonic range. Additional tests were conducted with carbon dioxide ejection, in order to analyze the mixing process downstream of the cascade.

Numerical 3-D Conjugate Flow and Heat Transfer Investigation of a Transonic Convection-Cooled Thermal Barrier Coated Turbine Guide Vane With Reduced Cooling Fluid Mass Flow

2003 ◽  
Author(s):  
Dieter E. Bohn ◽  
Christian Tu¨mmers
Keyword(s):  
Heat Transfer ◽  
Mass Flow ◽  
Gas Turbines ◽  
Thermal Stresses ◽  
Guide Vane ◽  
Cooling Fluid ◽  
Fluid Mass ◽  
Flow And Heat Transfer ◽  
Turbine Guide Vane ◽  
Good Agreement

The aerodynamics and aerothermics of a transonic convection-cooled turbine guide vane are investigated by application of a conjugate fluid flow and heat transfer solver, CHT-Flow. The code developed at the Institute of Steam and Gas Turbines, Aachen University, does not need any heat transfer data beforehand. Since the numerical results for the uncoated vane showed good agreement with experimental data, numerical investigations are extended for the coated vane. The investigated configuration consists of an APS (Athmospheric Plasma Spray) layer, while the external vane shape is preserved. For the coated configuration a parametric study of the cooling fluid mass flow has been performed with the aim of a smoothed temperature distribution in the blade material. Furthermore, with the help of a simplified thermal stress analysis the influence of the reduced cooling fluid mass flow on the thermal stresses in the blade material will be discussed in detail.

Thermodynamic Evaluation of Advanced Combined Cycle Using Latest Gas Turbine

2003 ◽  
Author(s):  
Sanjay ◽  
Onkar Singh ◽  
B. N. Prasad
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Specific Work ◽  
Thermodynamic Evaluation ◽  
Compressor Pressure Ratio ◽  
Steam Cooling ◽  
Plant Efficiency

The present work deals with the thermodynamic evaluation of combined cycle with re-heat in gas turbine using the latest gas turbines namely ABB GT26 gas turbine (advanced) in which reheat is used and the blade cooling is done by air bled from compressor. The same turbine is subjected to closed loop steam cooling. Parametric study has been performed on plant efficiency and specific work for various independent parameters such as turbine inlet temperature, compressor pressure ratio, reheating pressure ratio, reheater inlet temperature, blade temperature, etc.. It has been observed that due to higher compressor pressure ratio involved in reheat gas turbine combined cycle and higher temperature of exhaust, the plant efficiency and specific work are higher with the advanced reheat gas/steam combined cycle over the simple combined cycle. Steam cooling offers better performance over aircooling.

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