• 대한기계학회논문집B
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• 제30권4호
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• pp.328-336
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• 2006

Detailed heat transfer coefficient distributions an two. types of gas turbine blade tip, plane tip and squealer tip, were measured using a hue-detection base transient liquid crystals technique.. The heat transfer coefficients an the shroud and near tip regions of the pressure and suction sides af the blade were also. measured. The heat transfer measurements were taken at the three different tip gap clearances af 1.0%, 1.5%, and 2.5% of blade span. Results shaw the overall heat transfer coefficients on the tip and shroud with squealer tip blade were lower than those with plane tip blade. By using squealer tip, however, the reductions af heat transfer coefficients near the tip regions of the pressure and suction sides were nat remarkable.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.271-272
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• 2015

Gas turbine combustors is critical part due to high temperature operating conditions and the optimization of cooling design is required to avoid combustor failure. In gas turbine combustor, effusion cooling, impingement cooling and thermal barrier coating (TBC) are commonly used to improve cooling characteristics. In conceptual design, these cooling schemes are designed by 1D heat transfer calculation. Therefore, these design should be validated ted by nemurical or experiment methods. In this study, Conjugate Heat Transfer (CHT) analysis is performed for validation of gas turbine combustor cooling design.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.159-162
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• 2008

In this paper, a numerical simulation of three-dimensional flow field and heat transfer coefficient distribution are conducted for two types of gas turbine blade with plane and squealer tips. The numerical results show that gas turbine blade with squealer tip considerably changes the flow structures near the tip regions of pressure and suction sides, so the overall heat transfer coefficients on the tip and shroud with squealer tip are lower than those with the plane tip blade. Finally, the effect of tip gap clearance on the flow field and heat transfer characteristics are investigated.

• 한국항공운항학회지
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• 제14권2호
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• pp.33-38
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• 2006

Heat transfer coefficients and static pressure distributions on a gas turbine vane endwall were experimentally investigated in a 5 bladed linear cascade. The Reynolds number based on an axial chord length and the cascade exit velocity was 500,000. Both heat transfer and pressure measurements on the vane endwall were made at the two different turbulence intensity levels of 6.8% and 10.8%. Detailed heat transfer coefficient distributions on the vane endwall region were measured using a hue detection based transient liquid crystals technique. Results show various regions of high and low heat transfer coefficients on the vane endwall surface due to several types of secondary flows and vortices. Heat transfer coefficient and endwall static pressure distributions showed similar trends for both turbulence intensity, however, the averaged heat transfer coefficients for higher turbulence intensity case was higher than the lower turbulence intensity case by 15%.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.854-860
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• 2004

"Research and Development of Melt-Growth Composite (MGC) Ultra High Efficiency Gas Turbine System Technology" program has been started in JFY2001. The main objective of the program is to establish basic component technologies to apply MGC material to an efficient gas turbine system successfully. It is known that MGC material maintains its mechanical strength at room temperature up to about 2000 K, which is ideal for the high temperature gas turbine. The purposes of the present study are to develop the cooling structure of the gas turbine combustor liner where MGC material is applied as the heat shield panel, also to develop the low NOx combustion system for a 1970 K (1700 deg.C) class gas turbine combustor. To start with, basic heat transfer characteristics were investigated by one-dimensional calculation and heat transfer experiment for the cooling structure. Axially staged configuration and fuel preparation were investigated by CFD calculation and experiments for the low NOx combustor.

• 대한기계학회논문집B
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• 제26권9호
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• pp.1249-1259
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• 2002

The present study investigates the convective heat/mass transfer inside a cooling passage of rotating gas-turbine blades. The rotating duct has various configurations made of ribs with 70。 attack angle, which are attached on leading and trailing surfaces. A naphthalene sublimation technique is employed to determine detailed local heat transfer coefficients using the heat and mass transfer analogy. The present experiments employ two-surface heating conditions in the rotating duct because the surfaces, exposed to hot gas stream, are pressure and suction side surfaces in the middle passages of an actual gas-turbine blade. In the stationary conditions, the parallel rib arrangement presents higher heat/mass transfer characteristics in the first pass, however, these characteristics disappear in the second pass due to the turning effects. In the rotating conditions, the cross rib present less heat/mass transfer discrepancy between the leading and the trailing surfaces in the first pass. In the second pass, the heat/mass transfer characteristics are much more complex due to the combined effects of the angled ribs, the sharp fuming and the rotation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2946-2951
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• 2008

Combustion instability is a major issue in design of gas turbine combustors for efficient operation with low emissions. Combustion instability is induced by the interaction of the unsteady heat release of the combustion process and the change in the acoustic pressure in the combustion chamber. In an effort to develop a technique to predict self-excited combustion instability of gas turbine combustors, a new stability analysis method based on the transfer matrix method is developed. The method views the combustion system as a one-dimensional acoustic system with a side branch and describes the heat source as the input to the system. This approach makes it possible to use the advantages of not only the transfer matrix method but also well-established classic control theories. The approach is applied to a simple gas turbine combustion system to demonstrate the validity and effectiveness of the approach.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.30-35
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• 2001

To get higher efficiency of gas turbine, The designer should have more higher turbine inlet temperature (TIT). Today, modem gas turbine having sophisticated cooling scheme has TIT above $1,700^{\circ}C$. In the korea, many gas turbine having TIT above $1,300^{\circ}C$ was imported and being operated, but the gas with high TIT above $1,300^{\circ}C$ in the turbine will give damage to liner of combustor, and blade of turbine and etc. So frequently maintenance for parts enduring high temperature was performed. In this study, the heat transfer analysis of cooling air in the internal cooling channel (network analysis) and temperature analysis of the blade (Finite Element Analysis) in the first stage rotor was conducted for development of the optimal cooling passage design procedure. The results of network analysis and FEM analysis of blade show that the high temperature spot are occured at the leading edge, trailing edge near tip, and platform. so to get more reliable performance of gas turbine, the more efficient cooling method should be applied at the leading edge and tip section. and the thermal barrier coating on the blade surface has important role in cooling blade.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.430-435
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• 2003

Detailed heat transfer coefficient distributions on a gas turbine blade tip were measured using a hue-detection base transient liquid crystals technique. The heat transfer coefficients on the shroud and near tip regions of the pressure and suction sides of a blade were also measured. Both plane tip and squealer tip blade were considered. The heat transfer measurements were taken at the three different tip gap clearance of 1.0%, 1.5%, and 2.5% of blade span. Results show the overall heat transfer coefficients on the tip and shroud with squealer tip blade were lower than those with plane tip blade. However, the reductions of heat transfer coefficients near the tip regions of the pressure and suction sides were not remarkable.

• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.309-328
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• 2003

Catalytic combustion is the cleanest emissions technology that has been demonstrated for the gas turbine. It has been a primary part of the research portfolio for the Combustor and Heat Transfer Technology Group at Cranfield University since 1989. The Paper describes the background to studies in the Group, their evolution and presents some results for specific study areas and themes.