scholarly journals Analysis and Test of Coolant Flow and Heat Transfer of an Advanced Full-Coverage Film-Cooled Laminated Turbine Vane

1982 ◽  
Author(s):  
T. Yoshida ◽  
K. Takahara ◽  
T. Kumagai
Keyword(s):  
Test Data ◽  
Small Deviation ◽  
Flow Analysis ◽  
Coolant Flow ◽  
Flow Rate Ratio ◽  
Cooling Effectiveness ◽  
Flow And Heat Transfer ◽  
Turbine Vane ◽  
High Level ◽  
Cooling Passage

A laminated and diffusion bonded turbine vane was designed and manufactured with stainless steel wafers. By the use of photo chemical etching, it was possible to make many elaborate and fine cooling passages. The description of the cooling passage construction is given in this paper. Coolant flow analysis has been done and corrected with the aid of preliminary coolant flow discharge test data without the mainstream. Cooling effectiveness analysis by cascade test has also been performed. Corrected flow analysis shows good agreement with the cascade test data. The resulting cooling effectiveness distribution shows relatively small deviation from the averaged value and it is located at the high level of 0.7 with a coolant flow rate ratio of 6 percent. The analysis and discussion are also presented in this paper.

scholarly journals Cooling Characteristics of Film Cooled Turbine Vane Having Multi-Row of Ejection Holes

1978 ◽  
Author(s):  
K. Sakata ◽  
H. Usui ◽  
K. Takahara
Keyword(s):  
Flow Distribution ◽  
Leading Edge ◽  
Coolant Flow ◽  
Edge Region ◽  
Flow Ratio ◽  
Cooling Effectiveness ◽  
Cooling Performance ◽  
Turbine Vanes ◽  
Turbine Vane ◽  
Cooling Hole

Film-cooled turbine vanes having 14 rows of round holes were designed. Two-dimensional cascade tests of two kinds of scaled vanes were carried out and cooling performances were obtained. Coolant flow distributions were controlled by the impingement and plenum chamber configuration. Higher cooling effectiveness than 0.65 was obtained for the coolant flow ratio of 4.5 percent. And it was clarified that the distributions of cooling effectiveness of the vane surface was governed by the configuration of coolant flow distribution to the cooling hole rows, and, that with using relatively greater amount of coolant to the leading edge region, higher cooling performance can be obtained. Also, numerical calculations of cooling performance and prediction for turbine application were presented.

Nozzle Passage Endwall Effectiveness Values with Various Combustor Coolant Flow Rates - Part 1: Flowfield Velocity and Coolant Concentration Measurements

2021 ◽  
pp. 1-53
Author(s):  
Kedar P. Nawathe ◽  
Rui Zhu ◽  
Enci Lin ◽  
Yong Kim ◽  
Terrence Simon
Keyword(s):  
Flow Rate ◽  
Large Scale ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Coolant Flow ◽  
Surface Cooling ◽  
Cooling Effectiveness ◽  
Flow Rates ◽  
Flow Physics ◽  
High Level

Abstract The stators of the first stage of a gas turbine are exposed to severe temperatures. The coolant streams introduced to prevent the stators from thermal damage further complicate the highly three-dimensional vane passage flow. Recent results have shown that the coolant streams injected for cooling the combustor also influence the flow physics and the cooling effectiveness in the first-stage stator vanes passage. However, the effects of changing the mass flow rate of these combustor coolant streams on the passage flowfield have not been studied. As understanding the coolant transport is necessary for analyzing changes in cooling effectiveness in the vane passage, detailed aerodynamic and thermal measurements along the whole vane passage are required. This two-part paper presents such measurements taken for a variety of combustor coolant and endwall film coolant flow rates. The experiments were conducted in a low-Mach-number facility with engine-representative Reynolds numbers and large-scale high-level turbulence. The objective of the first part is to describe the flow that influences endwall and vane surface cooling effectiveness distributions, which are presented in the second part. The measurements show changes in the passage flowfield due to changes in both combustor coolant and endwall film coolant flow rates. Overall, the flow-physics remains largely unaffected by changes in coolant flow rates except in the endwall-vane surfaces region where the combustor coolant flow rate dominates changes in coolant transport. This is shown to have a high impact on endwall and vane surface cooling.

Nozzle Passage Endwall Effectiveness Values With Various Combustor Coolant Flow Rates: Part 1 — Flowfield Velocity and Coolant Concentration Measurements

2020 ◽  
Author(s):  
Kedar P. Nawathe ◽  
Rui Zhu ◽  
Enci Lin ◽  
Yong W. Kim ◽  
Terrence W. Simon
Keyword(s):  
Flow Rate ◽  
Large Scale ◽  
Guide Vane ◽  
Three Dimensional ◽  
Coolant Flow ◽  
Surface Cooling ◽  
Cooling Effectiveness ◽  
Flow Rates ◽  
Flow Physics ◽  
High Level

Abstract The stators of the first stage of a gas turbine are exposed to severe temperatures. The coolant streams introduced to prevent the stators from thermal damage further complicate the highly three-dimensional flow in the vane passage. Recent results have shown that, in addition to these coolant streams, the coolant streams injected for cooling the combustor also influence the flow physics and the cooling effectiveness in the first-stage stator vanes passage. However, the effects of changing the mass flow rate of these combustor coolant streams on the passage flowfield have not been studied. As understanding the coolant transport is necessary for analyzing changes in cooling effectiveness in the vane passage, detailed aerodynamic and thermal measurements along the whole vane passage are required. This two-part paper presents such measurements taken in a first-stage nozzle guide vane cascade for a variety of combustor coolant and endwall film coolant flow rates. The experiments were conducted in a low-Mach-number facility with engine-representative Reynolds numbers and large-scale high-level turbulence. The objective of the first part of the paper is to describe the flow that influences endwall and vane surface cooling effectiveness distributions, which are presented in the second part of this paper. The measurements show changes in the passage flowfield due to changes in both combustor coolant and endwall film coolant flow rates. Overall, the flow-physics remains largely unaffected by changes in coolant flow rates except in the endwall-vane surfaces region where the combustor coolant flow rate dominates changes in coolant transport. This is shown to have a high impact on endwall and vane surface cooling.

Numerical Study of the Effect of Blowing Angle on Cooling Effectiveness of an Effusion Cooling

2004 ◽  
Author(s):  
Yaping Hu ◽  
Honghu Ji
Keyword(s):  
Film Cooling ◽  
Numerical Study ◽  
Coolant Flow ◽  
Cooling Effectiveness ◽  
Absolute Value ◽  
Blowing Ratio ◽  
Conventional Film

The paper numerically investigates the influences of the blowing angle α of coolant flow on the cooling effectiveness of effusion cooling of a plate. Nine cases were studied which cover three blowing angles of α = 30°, 60°, 90° and for each angle three blowing ratios of M = 0.5, 1.0, 2.0 are calculated, respectively. The results show that with the increase of α the cooling effectiveness reduces for all the calculated cases. For the cases of α = 30° and 60° the distribution of cooling effectiveness η along the whole plate are very similar for any given blowing ratio, especially when M = 1.0 and 2.0. Whereas for the cases of α = 90°, the distributions of cooling effectiveness are quite different from other two blowing angles for a given blowing ratio, especially for M = 1.0 and in the trailing region of the plate. Although the cooling effectiveness of the cases with α = 90° for any given blowing ratio is the worst one among the three angles (α = 30°, 60°, and 90°) stated, its absolute value is still quite high comparing to the conventional film cooling.

Numerical Study on Flow and Heat Transfer of a Cooled First Stage Vane of a Gas Turbine

2016 ◽  
Author(s):  
Lv Ye ◽  
Zhao Liu ◽  
Xiangyu Wang ◽  
Zhenping Feng
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Film Cooling ◽  
Numerical Study ◽  
Coolant Flow ◽  
The Other ◽  
Edge Region ◽  
Flow Rates ◽  
Flow And Heat Transfer ◽  
Film Cooling Holes

This paper presents a numerical simulation of composite cooling on a first stage vane of a gas turbine, in which gas by fixed composition mixture is adopted. To investigate the flow and heat transfer characteristics, two internal chambers which contain multiple arrays of impingement holes are arranged in the vane, several arrays of pin-fins are arranged in the trailing edge region, and a few arrays of film cooling holes are arranged on the vane surfaces to form the cooling film. The coolant enters through the shroud inlet, and then divided into two parts. One part is transferred into the chamber in the leading edge region, and then after impinging on the target surfaces, it proceeds further to go through the film cooling holes distributed on the vane surface, while the other part enters into the second chamber immediately and then exits to the mainstream in two ways to effectively cool the other sections of the vane. In this study, five different coolant flow rates and six different inlet pressure ratios were investigated. All the cases were performed with the same domain grids and same boundary conditions. It can be concluded that for the internal surfaces, the heat transfer coefficient changes gradually with the coolant flow rate and the inlet total pressure ratio, while for the external surfaces, the average cooling effectiveness increases with the increase of coolant mass flow rates while decreases with the increase of the inlet stagnation pressure ratios within the study range.

Numerical Investigation of the Cooling Performance on the Endwall With and Without Fillet

2018 ◽  
Author(s):  
Qingzong Xu ◽  
Qiang Du ◽  
Pei Wang ◽  
Jun Liu ◽  
Guang Liu
Keyword(s):  
Secondary Flow ◽  
Turbulence Model ◽  
Film Cooling ◽  
Computational Method ◽  
Inlet Temperature ◽  
Cooling Effectiveness ◽  
Cooling Performance ◽  
Film Cooling Effectiveness ◽  
Numerical Predictions ◽  
Turbine Vane

High inlet temperature of turbine vane increases the demand of high film cooling effectiveness. Vane endwall region was extensively cooled due to the high and flat exit temperature distribution of combustor. Leakage flow from the combustor-turbine gap was used to cool the endwall region except for preventing hot gas ingestion. Numerical predictions were conducted to investigate the flow structure and adiabatic film cooling effectiveness of endwall region in a linear cascade with vane-endwall junction fillet. The simulations were completed by solving the three-dimensional Reynolds-Averaged Navier-Stokes(RANS) equations with shear stress transport(SST) k-ω turbulence model, meanwhile, the computational method and turbulence model were validated by comparing computational result with the experiment. Three types of linear fillet with the length-to-height ratio of 0.5, 1 and 2, named fillet A, fillet B and fillet C respectively, were studied. In addition, circular fillet with radius of 2mm was compared with linear fillet B. The interrupted slot, produced by changing the way of junction of combustor and turbine vane endwall, is introduced at X/Cax = −0.2 upstream of the vane leading edge. Results showed that fillet can significantly affect the cooling performance on the endwall due to suppressing the strength of the secondary flow. Fillet C presented the best cooling performance comparing to fillet A and fillet B because a portion of the coolant which climbs to the fillet was barely affected by secondary flow. Results also showed the effect of fillet on the total pressure loss. The result indicated that only fillet A slightly decreases endwall loss.

Turbine Platform Cooling and Blade Suction Surface Phantom Cooling From Simulated Swirl Purge Flow

2015 ◽  
Author(s):  
Shiou-Jiuan Li ◽  
Jiyeon Lee ◽  
Je-Chin Han ◽  
Luzeng Zhang ◽  
Hee-Koo Moon
Keyword(s):  
Relative Motion ◽  
Film Cooling ◽  
Density Ratio ◽  
Flow Rate Ratio ◽  
Swirl Ratio ◽  
Suction Surface ◽  
Cooling Effectiveness ◽  
Coolant Injection ◽  
Purge Flow ◽  
Cylindrical Holes

The paper presents the swirl purge flow on platform and a modeled land-based turbine rotor blade suction surface. Pressure sensitive paint (PSP) mass transfer technique provides detailed film cooling effectiveness distribution on platform and phantom cooling effectiveness on blade suction surface. Experiments have completed in a low speed wind tunnel facility with a five blade linear cascade. The inlet Reynolds number based on the chord length is 250,000. Swirl purge flow is simulated by coolant injection through fifty inclined cylindrical holes ahead of the blade leading edge row. Coolant injections from cylindrical holes go through nozzle endwall and a dolphin nose axisymmetric contour before reach platform and blade suction surface. Different “coolant injection angles” and “coolant injection velocity to cascade inlet velocity” results in various swirl ratios to simulate real engine conditions. Simulated swirl purge flow uses coolant injection angles of 30, 45, and 60 degrees to produce swirl ratios of 0.4, 0.6, and 0.8, respectively. Traditional purge flow has coolant injection angle of 90 degree to generate swirl ratio of 1. Coolant to mainstream mass flow rate ratio (MFR) is 0.5%, 1.0% and 1.5% for all swirl ratios. Coolant to mainstream density ratio maintains at 1.5 to match engine conditions. Most of the swirl purge and purge coolant approaches platform, but small amount of the coolant migrates to blade suction surface. Swirl ratio of 0.4 has highest relative motion between rotor and coolant and severely decreases film cooling and phantom cooling effectiveness. Higher MFR of 1% and 1.5% cases suffer from apparent decrement of the effectiveness while increasing relative motion.

scholarly journals HOW TO INCREASE CIRCULARITY IN THE SWISS ECONOMY?

Detritus ◽  
2021 ◽  
pp. 25-31
Author(s):  
Cecilia Matasci ◽  
Marcel Gauch ◽  
Heinz Boeni
Keyword(s):  
Economic System ◽  
Circular Economy ◽  
Material Flow ◽  
Raw Materials ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Material Flows ◽  
Environmental Threats ◽  
High Level ◽  
Recycled Waste

Environmental threats are triggered by the overconsumption of raw materials. It is therefore necessary to move towards a society that both reduces extraction and keeps the majority of the extracted raw materials in the socio-economic system. Circular economy is a key strategy to reach these goals. To implement it effectively, it is necessary to understand and monitor material flows and to define hotspots, i.e. materials that need to be tackled with the highest priority. This paper is aimed at determining how to increase circularity in the Swiss economy by means of a Material Flow Analysis coupled with a simplified Life Cycle Assessment. After having characterized material flows, we analyzed two types of hotspots: i) Raw materials consumed and/or disposed at high level, and ii) Raw materials whose extraction and production generates high environmental impacts. The Material Flow Analysis shows that each year 119 Mt of raw materials enter the Swiss economy. Therefrom, 15 Mt are derived from recycled waste inside the country; 67 Mt leave the system yearly; 27 Mt towards disposal. Out of the disposed materials, 56% are recycled and re-enter the socio-economic system as secondary materials. Looking at hotspots; concrete, asphalt, gravel and sand are among materials that are consumed and disposed at high level. Yet, looking at greenhouse gas emissions generated during extraction and production, metals - including the ones in electrical and electronic equipment - as well as textiles are among the categories that carry the biggest burden on the environment per unit of material.

Numerical Study of Heat Transfer and Cooling Effectiveness on a Flat-Tip Turbine Blade

2013 ◽  
Author(s):  
Qihe Huang ◽  
Jiao Wang ◽  
Lei He ◽  
Qiang Xu
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Film Cooling ◽  
Numerical Study ◽  
Leakage Flow ◽  
Tip Leakage Flow ◽  
Cooling Effectiveness ◽  
Blowing Ratio ◽  
Flow And Heat Transfer ◽  
Blade Tip

A numerical study is performed to simulate the tip leakage flow and heat transfer on the first stage rotor blade tip of GE-E3 turbine, which represents a modern gas turbine blade geometry. Calculations consist of the flat blade tip without and with film cooling. For the flat tip without film cooling case, in order to investigate the effect of tip gap clearance on the leakage flow and heat transfer on the blade tip, three different tip gap clearances of 1.0%, 1.5% and 2.5% of the blade span are considered. And to assess the performance of the turbulence models in correctly predicting the blade tip heat transfer, the simulations have been performed by using four different models (the standard k-ε, the RNG k-ε, the standard k-ω and the SST models), and the comparison shows that the standard k-ω model provides the best results. All the calculations of the flat tip without film cooling have been compared and validated with the experimental data of Azad[1] and the predictions of Yang[2]. For the flat tip with film cooling case, three different blowing ratio (M = 0.5, 1.0, and 1.5) have been studied to the influence on the leakage flow in tip gap and the cooling effectiveness on the blade tip. Tip film cooling can largely reduce the overall heat transfer on the tip. And the blowing ratio M = 1.0, the cooling effect for the blade tip is the best.

High-Level Restructuring of TTCN-3 Test Data

2005 ◽  
pp. 180-194 ◽  
Author(s):  
Antal Wu-Hen-Chang ◽  
D ung Le Viet ◽  
Gabor Batori ◽  
Roland Gecse ◽  
Gyula Csopaki
Keyword(s):  
Test Data ◽  
High Level
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