Experimental Study on Influence of Cooling Air Flow Upon Surface Temperature of High-Temperature Turbine Blades in Gas Turbine

2012 ◽  
Author(s):  
Xueyou Wen ◽  
Dongming Xiao ◽  
Zhongming Gu ◽  
Shugui Du
Keyword(s):  
Experimental Study ◽  
Surface Temperature ◽  
Turbine Blades ◽  
Casting Process ◽  
Blade Row ◽  
Cooling Media ◽  
Cooling Air Flow ◽  
Lp Turbine ◽  
Cooling Air ◽  
Obvious Relation

On the basis of the issues occurring in practical production, an experimental study on the influence of cooling media flow upon the surface temperatures of LP turbine blades is carried out on a turbine. The experiment results show that, when the tolerance range of the cooling media flow is narrowed, the surface temperature difference of the blades in blade row is also narrowed evidently, while it has no obvious relation to the “corresponding probability” between the cooling media flow and the blade surface temperature. A few blades even show a “full non-corresponding” relationship. The reason of this phenomenon is that the vortex-matrix type inner cooling structure of blades makes the casting process more complex. The experiment results are helpful to the confirmation of the water flow tolerance in reason and the perfection of the process detail.

scholarly journals Analysis of the energetic/environmental performances of gas turbine plant: Effect of thermal barrier coatings and mass of cooling air

2009 ◽  
Vol 13 (1) ◽  
pp. 147-164 ◽  
Author(s):  
Ion Ion ◽  
Anibal Portinha ◽  
Jorge Martins ◽  
Vasco Teixeira ◽  
Joaquim Carneiro
Keyword(s):  
Thermal Conductivity ◽  
Gas Turbine ◽  
Thermal Barrier Coatings ◽  
Turbine Blades ◽  
Heat Transfer Analysis ◽  
Thermal Barrier ◽  
Inlet Temperature ◽  
Barrier Coatings ◽  
Cooling Air Flow ◽  
Cooling Air

Zirconia stabilized with 8 wt.% Y2O3 is the most common material to be applied in thermal barrier coatings owing to its excellent properties: low thermal conductivity, high toughness and thermal expansion coefficient as ceramic material. Calculation has been made to evaluate the gains of thermal barrier coatings applied on gas turbine blades. The study considers a top ceramic coating Zirconia stabilized with 8 wt.% Y2O3 on a NiCoCrAlY bond coat and Inconel 738LC as substrate. For different thickness and different cooling air flow rates, a thermodynamic analysis has been performed and pollutants emissions (CO, NOx) have been estimated to analyze the effect of rising the gas inlet temperature. The effect of thickness and thermal conductivity of top coating and the mass flow rate of cooling air have been analyzed. The model for heat transfer analysis gives the temperature reduction through the wall blade for the considered conditions and the results presented in this contribution are restricted to a two considered limits: (1) maximum allowable temperature for top layer (1200?C) and (2) for blade material (1000?C). The model can be used to analyze other materials that support higher temperatures helping in the development of new materials for thermal barrier coatings.

Cooling Air Temperature Reduction in a Direct Transfer Preswirl System

2003 ◽  
Author(s):  
T. Geis ◽  
M. Dittmann ◽  
K. Dullenkopf
Keyword(s):  
Experimental Study ◽  
Reynolds Numbers ◽  
Viscous Drag ◽  
Direct Transfer ◽  
One Dimensional ◽  
Simple Theoretical Model ◽  
Air Temperatures ◽  
Total Temperature ◽  
Cooling Air Flow ◽  
Cooling Air

This paper describes an experimental study of the cooling efficiency of a preswirl rotor-stator system equipped with a small number of preswirl nozzles of circular shape, located on a radius equal to that of the receiver disk holes. In the direct transfer cooling air system, total air temperatures were measured in the relative frame, i.e. inside the receiver holes by means of small total temperature probes for different throughflow rates, rotational Reynolds numbers and swirl ratios. The experimental data were compared with a simple theoretical model which predicts air temperatures in an “ideal” preswirl system. This comparison served to quantify the efficiency of this cooling scheme. In a subsequent one-dimensional analysis which took into account flow data obtained in an earlier experimental study by the same authors, two different mechanisms responsible for the elevated cooling air temperatures were determined. The new model considers in addition to the observed reduction of swirl due to viscous drag on the stator and mixing inside the rotor-stator cavity, the work put in by the rotor at high disk rotational Reynolds numbers and low cooling air flow rates.

scholarly journals A method for calculation of forces acting on air cooled gas turbine blades based on the aerodynamic theory

2013 ◽  
Vol 17 (2) ◽  
pp. 547-554
Author(s):  
Vojin Grkovic
Keyword(s):  
Gas Turbine ◽  
Flow Parameter ◽  
Turbine Blades ◽  
Blade Profile ◽  
Air Mass ◽  
Gas Turbine Blades ◽  
Axial Forces ◽  
Cooling Air Flow ◽  
Cooling Air ◽  
The Mathematical Model

The paper presents the mathematical model and the procedure for calculation of the resultant force acting on the air cooled gas turbine blade(s) based on the aerodynamic theory and computation of the circulation around the blade profile. In the conducted analysis was examined the influence of the cooling air mass flow expressed through the cooling air flow parameter ?c, as well as, the values of the inlet and outlet angles ?1 and ?2, on the magnitude of the tangential and axial forces. The procedure and analysis were exemplified by the calculation of the tangential and axial forces magnitudes.

Numerical Investigations of Fluid Flow and Heat Transfer Performances of Semiattached Rib Channel Design

2010 ◽  
Author(s):  
Jianhua Wang ◽  
Huichun Liu ◽  
Mao Mao ◽  
Xu Li ◽  
Zhiqiang Zhang
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Turbine Blades ◽  
Number Range ◽  
Flow And Heat Transfer ◽  
Transfer Region ◽  
Side Walls ◽  
Pass Through ◽  
Cooling Air Flow ◽  
Cooling Air

In order to enhance the convective heat transfer within cooling air flow channels, fully attached rib-designs have been widely used in the designs of turbine blades. To reduce the friction loss and the low heat transfer areas caused by the added ribs, permeable and detached ribs have been discussed. This work focuses on a novel rib-design, between the fully attached and detached ribs, which is therefore called semiattched rib here. To effectively reduce the low heat transfer region within the fully attached rib channel, two rectangular holes are excavated at the base of a straight rib at both concave corners of the bottom and side walls. The rest of the rib is attached to the base wall of the channel. A portion of coolant air can pass through the holes. To discuss the characteristics of the semiattached rib-designs, a numerical investigation has been performed by the commercial software Fluent 6.3, with the Reynolds number range from 104 to 2.5×104. The numerical results indicate that though the area-average heat transfer performances of the semiattached rib-designs are worse, the corresponding fluid flow performance are much better than both of fully attached and detached rib-designs. Another important performance is that the semiattached rib-design can fully eliminated the low heat transfer areas within the ribbed channel.

Experimental Study of Swirl Cooling Flow on a Circular Chamber Using 3-D Stereo-PIV

2018 ◽  
Author(s):  
Daisy Galeana ◽  
Asfaw Beyene
Keyword(s):  
Experimental Study ◽  
Turbine Blades ◽  
Swirl Flow ◽  
Internal Cooling ◽  
Swirl Number ◽  
Maximum Heat ◽  
Cooling Flow ◽  
Maximum Heat Transfer ◽  
Flow Phenomena ◽  
Cooling Air

Experimental study of a swirl flow using 3-D Stereo-PIV (Particle Image Velocimetry) that models a gas turbine blade internal cooling configuration is presented. The work is intended to provide an understanding of the advancements of swirl cooling flow methodology utilizing 3-D Stereo-PIV. The study aims at determining the critical swirl number that has the potential to deliver the maximum heat transfer results. In the swirl cooling flow methodology, cooling air is routed to the turbine blades where it passes through the blade’s internal passages lowering the temperature. An experimental setup with seven discrete tangential jets at three different Reynolds numbers is designed to allow detail measurements of the flow. To provide the particles for velocity measurements an oil particle seeder (LAVision) is used. The circular chamber is made of clear acrylic to allow visualization of the flow phenomena. Data is post-processed in DaVis, velocity calculations are conducted in MATLAB, and TechPlot is used for data visualization. This investigation focuses on the continuous swirl flow that must be maintained via continuous injection of tangential flow, where swirl flow is generated with seven inlets and decays with downstream distance. It was also determined that the critical swirl number, Sn, depends greatly on the location and size of the tangential slots.

scholarly journals Cooling Characteristics of Film-Cooled Turbine Blades

1984 ◽  
Author(s):  
T. Abe ◽  
N. Doi ◽  
T. Kawaguchi ◽  
T. Yamane ◽  
T. Kumagai ◽  
...  
Keyword(s):  
Film Cooling ◽  
Small Deviation ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Cooling Effectiveness ◽  
Average Value ◽  
Pin Fin ◽  
Series Of Experiments ◽  
Cooling Air Flow ◽  
Cooling Air

A series of experiments was performed to measure the cooling effectiveness of pin-fin type blades applicable to the first-stage blades of the high pressure turbine for the Advanced Gas Turbine of Japan (AGTJ-100A). Actual pin-fin type blades were used in three-dimensional hot cascade tests. Resulting cooling effectiveness distributions in chordwise direction showed relatively small deviation from the high average value and closely corresponded with analytical predictions. Another major finding was that for film cooling blades, particularly with a shower head film cooling, it is essential in the cascade tests to set the ratio between the coolant and mainstream temperature at values the same as real conditions. This makes it possible to simulate cooling air flow distributions in the blades of high temperature actual turbines using low temperature tests. This is also applicable to vanes with a shower head film cooling.

Cooling Air Temperature Reduction in a Direct Transfer Preswirl System

2004 ◽  
Vol 126 (4) ◽  
pp. 809-815 ◽  
Author(s):  
T. Geis ◽  
M. Dittmann ◽  
K. Dullenkopf
Keyword(s):  
Experimental Study ◽  
Reynolds Numbers ◽  
Viscous Drag ◽  
Direct Transfer ◽  
One Dimensional ◽  
Simple Theoretical Model ◽  
Air Temperatures ◽  
Total Temperature ◽  
Cooling Air Flow ◽  
Cooling Air

This paper describes an experimental study of the cooling efficiency of a preswirl rotor-stator system equipped with a small number of preswirl nozzles of circular shape, located on a radius equal to that of the receiver disk holes. In the direct transfer cooling air system, total air temperatures were measured in the relative frame, i.e., inside the receiver holes by means of small total temperature probes for different throughflow rates, rotational Reynolds numbers and swirl ratios. The experimental data were compared with a simple theoretical model which predicts air temperatures in an “ideal” preswirl system. This comparison served to quantify the efficiency of this cooling scheme. In a subsequent one-dimensional analysis which took into account flow data obtained in an earlier experimental study by the same authors, two different mechanisms responsible for the elevated cooling air temperatures were determined. The new model considers in addition to the observed reduction of swirl due to viscous drag on the stator and mixing inside the rotor-stator cavity, the work put in by the rotor at high disk rotational Reynolds numbers and low cooling air flow rates.

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