Application of a Heat Flux/Calorimeter-Based Method to Assess the Effect of Turbulence on Turbine Airfoil Heat Transfer

Glazer, B.; Moon, Hyunkyu; Zhang, L.; Camcı, Cengiz

doi:10.1115/94-gt-095

Cited by 4 publications

(3 citation statements)

References 2 publications

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“…The tests were performed in the hot-cascade which was featured in earlier papers (Glezer et al, 1994;Zhang and Glezer, 1995;Moon and Glezer, 1996). The realistic production configuration nozzle was selected for the heat transfer measurement.…”

Section: Test Facility and Instrumentationmentioning

confidence: 99%

Turbine Airfoil External Heat Transfer Measurement in a Hot-Cascade

Zhang¹,

Glezer²

1997

Volume 3: Heat Transfer; Electric Power; Industrial and Cogeneration

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Detailed knowledge of local external heat transfer around a turbine airfoil is critical for an accurate prediction of metal temperature and component life. This paper discusses the results of measurements of the local gas side heat transfer coefficient distribution which were performed in an annular gas turbine vane hot-cascade test facility and provides comparisons with analytical predictions. The steady state tests were performed at simulated engine operating conditions. The tests were conducted on an internally cooled airfoil with the intent to provide close to uniform coolant temperature at the mid-span of the airfoil and also to obtain a high heat flux through the wall, minimizing uncertainty. Internal coolant side heal transfer coefficients were measured through calibration tests outside the cascade by a wire heater. A calibrated infrared pyrometer was used to provide detailed airfoil surface local temperatures and the corresponding external heat transfer coefficients. The airfoil was instrumented with a number of thermocouples for both calibration and temperature measurement. A 12% freestream turbulence was generated by a turbulence grid upstream of the test cascade. The static pressure measured over the test vane agreed well with invicid predictions. Heat transfer coefficients were measured and compared to a TEXSTAN boundary layer code prediction. The influence of Reynolds number and Mach number on the airfoil external heat transfer coefficient were also studied and is presented in the paper.

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Section: Test Facility and Instrumentationmentioning

confidence: 99%

Turbine Airfoil External Heat Transfer Measurement in a Hot-Cascade

Zhang¹,

Glezer²

1997

Volume 3: Heat Transfer; Electric Power; Industrial and Cogeneration

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“…The test blade was instrumented with 0.25 mm outer shell diametered thermocouple buried flush into the wall. The details of the hot cascade have been described by Glezer et al (1994). The pyrometer was mounted in a traversing device with rotational freedom to scan the mid- section of the test blade.…”

Section: Figure 3 Distance Dependency Of the Pyrometer Validation Inmentioning

confidence: 99%

“…transfer/aerodynamic characteristics of an actual engine airfoil during the course of turbine component development as discussed by Glezer (1992), operates at much lower gas temperatures and the corresponding metal component temperatures typically range between 400°C and 700°C. Another important low temperature application of a pyrometer is a field diagnostic of the thermocouples controlling the engine.…”

Section: Introductionmentioning

confidence: 99%

Development of a Wide Range Temperature Pyrometer for Gas Turbine Application

Moon¹,

Glezer²,

Mink³

et al. 1995

Volume 1: Turbomachinery

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The applications of optical pyrometry in gas turbines are diverse. Optical pyrometry provides many advantages over other techniques for temperature measurement. The inherent problems associated with low temperature measurement have limited optical pyrometry equipment for the hot cascade and low temperature turbine component applications. Traditional uses of this type of equipment have been limited to high temperature (>600°C) measurements. A wide range temperature pyrometer (>230°C) with unique design concepts was developed to address these issues. The pyrometer effectively operated in a long wavelength (2.00 to 2.25 mm) radiation to measure a relatively low temperature, as well as avoid the absorption bands of the gases commonly present in gas turbines. It was analytically and experimentally proven that the pyrometer was practically insensitive to the distance and view angle. The pyrometer was calibrated in a controlled-temperature model, and its reliability and applicability were demonstrated in a hot cascade environment.

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Heat Transfer in a Rotating Radial Channel With Swirling Internal Flow

Glezer¹,

Moon²,

Kerrebrock

et al. 1998

Volume 4: Heat Transfer; Electric Power; Industrial and Cogeneration

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This paper presents experimental results for heat transfer in swirling internal flow, obtained in two ways. A test rig simulated a rotating blade’s leading edge internal passage with heated walls and screw-shaped cooling swirl generated by flow introduced through discrete tangential slots. Spatially resolved variations of the surface heat transfer coefficients were measured in the rotating rig using an IR radiometer. A blade tested in the actual engine environment had similar geometry of the leading edge cooling passage. The blade surface temperatures were mapped in the engine with thermal paints and compared with a traditional convective cooling configuration. The data from the rotating rig and engine measurements are also compared with non-rotating heat transfer results obtained in the hot cascade using a traversing pyrometer at a realistic wall-to-coolant temperature ratio. The results are presented for realistic rotational numbers, ranging from 0 to 0.023, and for representative Reynolds number of 20,000 based on the channel diameter. The effect of Coriolis forces is evident with the change of direction of the rotation. A slight negative influence of the crossflow, which increased toward the outer radius of the channel, was recorded in the rig test results. The results presented will assist in better understanding of the screw-shaped swirl cooling technique, providing the next step toward the application of this highly-effective internal cooling method for the leading edges of turbine blades.

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Application of a Heat Flux/Calorimeter-Based Method to Assess the Effect of Turbulence on Turbine Airfoil Heat Transfer

Cited by 4 publications

References 2 publications

Turbine Airfoil External Heat Transfer Measurement in a Hot-Cascade

Turbine Airfoil External Heat Transfer Measurement in a Hot-Cascade

Development of a Wide Range Temperature Pyrometer for Gas Turbine Application

Heat Transfer in a Rotating Radial Channel With Swirling Internal Flow

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