An integrated approach to the application of high bandwidth optical pyrometry to turbine blade surface temperature mapping

2003 ◽  
Author(s):  
J. Douglas ◽  
C.A. Smith ◽  
S.J.R. Taylor
Keyword(s):  
Surface Temperature ◽  
Turbine Blade ◽  
Integrated Approach ◽  
Blade Surface ◽  
Optical Pyrometry ◽  
Temperature Mapping ◽  
High Bandwidth

Colour changing material for the estimation of flue gas radiation on the miniature gas turbine surface

2021 ◽  
pp. 146442072110455
Author(s):  
Mahalingam Arulprakasajothi ◽  
Pegyyem Lokaiah Rupesh ◽  
Hitesh Kumar Rana ◽  
Kariappan Elangovan
Keyword(s):  
Fluid Dynamics ◽  
Temperature Gradient ◽  
Surface Temperature ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Flue Gas ◽  
Dynamics Simulation ◽  
Blade Surface ◽  
Numerical Validation ◽  
Surface Temperature Gradient

The gas turbine is being used in the applications of the aircraft propulsion system and land-based power generating systems more effectively. The manufacturers should optimise the temperature of the gas turbine engine components to enhance the life span of the components. The present research work concentrates on determining the surface temperature gradient on the fabricated turbine blades using a colour changing paint based on temperature attained on the surface. A calibration database has been created, and the surface temperature has been detected based on the available colour contours on the blade surface using human vision. An image processing algorithm has also been proposed for accurate temperature measurement on the blade surface. The obtained surface temperature using colour changing paint multi-colour change 350-8 has been calibrated with the conventional measurement technique IR thermography for experimental validation. A computational fluid dynamics simulation model of the turbine blade has been simulated to predict the surface temperature of blades using analysis systems fluid dynamics for numerical validation. The experimental and numerical validation results have shown a nominal value of error, which proves that the surface temperature gradient can be easily predicted with the help of temperature indicating paint using the proposed algorithm. The study has been extended further to evaluate the amount of emissive power radiated by the flue gas on the turbine blade surface based on the temperature and the wavelength of the colour obtained for the health monitoring of the blade.

Effective Spectral Emissivity of Gas Turbine Blades for Optical Pyrometry

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Jibin Tian ◽  
Tairan Fu ◽  
Qiaoqi Xu ◽  
Hongde Jiang
Keyword(s):  
Turbine Blade ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Engine Performance ◽  
Spectral Emissivity ◽  
Temperature Measurements ◽  
Blade Surface ◽  
Effective Emissivity ◽  
Optical Pyrometry ◽  
Actual Surface

Turbine blade temperature measurements are important for monitoring the turbine engine performance to protect the hot components from damage due to excess temperatures. However, the reflected radiation from the blades and the surrounding environment complicate the blade temperature measurements by optical pyrometers. This study characterizes the effect of the reflected radiation on the effective spectral emissivity of a three-dimensional turbine blade in a confined turbine space for optical pyrometry temperature measurements. The effective spectral emissivity distribution on a three-dimensional blade was numerically determined for various wavelengths (0.8–15.0 μm) and actual blade surface emissivities for a specified turbine blade model. When the actual spectral emissivity of the blade surface is assumed to be 0.5, the effective spectral emissivity varies from 0.5 to 0.538 at the longer wavelength of 10.0 μm and further increases from 0.5 to 1.396 at the shorter wavelength of 0.9 μm. The results show that the effective emissivity distributions at shorter wavelengths differ greatly from those at longer wavelengths. There are also obvious differences between the effective spectral emissivity and the actual surface emissivity at shorter wavelengths. The effect of the effective emissivity on the temperature measurement accuracy, when using the optical pyrometry, was also investigated for various wavelengths (0.8–15.0 μm). The results show that the radiation reflected from the blades has less effect on the temperature measurements than on the effective emissivity, especially at the shorter wavelengths of 0.8–3.0 μm. However, the temperature measurements still need to be corrected using the effective spectral emissivity to improve the temperature calculation accuracy. This analysis provides guidelines for choosing the optimum measurement wavelengths for optical pyrometry in turbine engines.

Effects of Rotation on Blade Surface Heat Transfer: An Experimental Investigation

1997 ◽  
Author(s):  
Roger W. Moss ◽  
Roger W. Ainsworth ◽  
Tom Garside
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Experimental Investigation ◽  
Turbine Blade ◽  
Time History ◽  
Surface Heat ◽  
Blade Surface ◽  
Surface Heat Transfer ◽  
Effects Of Rotation ◽  
Wake Passing

Measurements of turbine blade surface heat transfer in a transient rotor facility are compared with predictions and equivalent cascade data. The rotating measurements involved both forwards and reverse rotation (wake free) experiments. The use of thin-film gauges in the Oxford Rotor Facility provides both time-mean heat transfer levels and the unsteady time history. The time-mean level is not significantly affected by turbulence in the wake; this contrasts with the cascade response to freestream turbulence and simulated wake passing. Heat transfer predictions show the extent to which such phenomena are successfully modelled by a time-steady code. The accurate prediction of transition is seen to be crucial if useful predictions are to be obtained.

scholarly journals Rocket Engine Turbine Blade Surface Pressure Distributions: Experiment and Computations

2003 ◽  
Vol 19 (3) ◽  
pp. 364-373 ◽  
Author(s):  
Susan T. Hudson ◽  
Thomas F. Zoladz ◽  
Daniel J. Dorney
Keyword(s):  
Turbine Blade ◽  
Surface Pressure ◽  
Rocket Engine ◽  
Blade Surface ◽  
Pressure Distributions

The ultra-high efficiency gas turbine engine, UHEGT, Part II: A numerical study on reducing the stator blade surface temperature by indexing fuel injectors and using film cooling

2020 ◽  
pp. 095765092097353
Author(s):  
Seyed M Ghoreyshi ◽  
Meinhard T Schobeiri
Keyword(s):  
Surface Temperature ◽  
Gas Turbine ◽  
Film Cooling ◽  
Total Pressure ◽  
High Efficiency ◽  
Combustion Process ◽  
Blade Surface ◽  
Turbine Engine ◽  
Fuel Injectors ◽  
Stator Blade

In the Ultra-High Efficiency Gas Turbine Engine, UHEGT (introduced in our previous studies) the combustion process is no longer contained in isolation between the compressor and turbine, rather distributed within the axial gaps before each stator row. This technology substantially increases the thermal efficiency of the engine cycle to above 45%, increases power output, and reduces turbine inlet temperature. Since the combustion process is brought into the turbine stages in UHEGT, the stator blades are exposed to high-temperature gases and can be overheated. To address this issue and reduce the temperature on the stator blade surface, two different approaches are investigated in this paper. The first is indexing (clocking) of the fuel injectors (cylindrical tubes extended from hub to shroud), in which the positions of the injectors are adjusted relative to each other and the stator blades. The second is film cooling, in which cooling holes are placed on the blade surface to bring down the temperature via coolant injection. Four configurations are designed and studied via computational fluid dynamics (CFD) to evaluate the effectiveness of the two approaches. Stator blade surface temperature (as the main objective function) along with other performance parameters such as temperature non-uniformity at rotor inlet, total pressure loss over the injectors, and total power production by rotor are evaluated for all configurations. The results show that indexing presents the most promising approach in reducing the stator blade surface temperature while producing the least amount of total pressure loss.

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