A Fiber-Optic Tip-Shroud Deflection Measurement System

2000 ◽  
Vol 123 (2) ◽  
pp. 359-362 ◽  
Author(s):  
R. A. Rooth ◽  
W. Hiemstra
Keyword(s):  
Gas Turbine ◽  
Fiber Optic ◽  
Turbine Blades ◽  
Stable Operation ◽  
Distance Information ◽  
Optical Signals ◽  
Good Spatial Resolution ◽  
Characteristic Features ◽  
The Individual ◽  
Tip Shroud

A Dutch utility faced the fact that a second stage set of turbine blades of a gas turbine had to be replaced long before the estimated lifetime as a result of tip shroud deflection. This deflection caused the risk of loss of support between the individual tip shroud segments. The goal of this paper is to find the cause of the problem, to see how it increases with time, and to take appropriate action to prevent the problem from occurring again. A fiber-optic tip-shroud deflection monitor has been developed and tested on a gas turbine to study this phenomenon in real time. The optical system is based on astigmatism to derive distance information from the measured optical signals. Characteristic features from the system are the good spatial resolution of about 1 mm, the distance resolution of about 0.1 mm and the distance from the probe tip to the target of about 20 mm. These specifications are difficult to achieve with, for example, capacitive sensors. The probe tip can with stand temperatures of about 500°C. The system can be calibrated in situ, given a stable operation of the gas turbine. This is accomplished by stepping the probe tip over some distance and recording the signals corresponding to a certain point on the tip shroud. The instrument has been used to monitor the tip-shroud deflection in a gas turbine at various loads and over a time span of several months. The results indicate that the deflection can be divided in a part depending on the load and a part that is a permanent deflection. Based on the results, it can be judged whether blades need to be rejected because of a too large deflection.

A Fiber-Optic Tip-Shroud Deflection Measurement System

2000 ◽  
Author(s):  
Rudy A. Rooth ◽  
Wiebren Hiemstra
Keyword(s):  
Gas Turbine ◽  
Fiber Optic ◽  
Turbine Blades ◽  
Stable Operation ◽  
Distance Information ◽  
Optical Signals ◽  
Good Spatial Resolution ◽  
Characteristic Features ◽  
The Individual ◽  
Tip Shroud

A dutch utility faced the fact that a second stage set of turbine blades of a gas turbine had to be replaced long before the estimated lifetime as a result of tip shroud deflection. This deflection caused the risk of loss of support between the individual tip shroud segments. The goal is to find the cause of the problem, to see how it increases with time and to take appropriate action to prevent the problem from occurring again. A fiber-optic tip-shroud deflection monitor has been developed and tested on a gas turbine (Davinson, 1987) to study this phenomenon in real time.. The optical system is based on astigmatism to derive distance information from the measured optical signals. Characteristic features from the system are the good spatial resolution of about 1 millimeter, the distance resolution of about 0.1 millimeter and the distance from the probe tip to the target of about 20 millimeter. These specifications are difficult to achieve with for example capacitive sensors. The probe tip can withstand temperatures of about 500 °C. The system can be calibrated in situ, given a stable operation of the gas turbine. This is accomplished by stepping the probe tip over some distance and recording the signals corresponding to a certain point on the tip shroud. The instrument has been used to monitor the tip-shroud deflection in a gas turbine at various loads and over a time span of several months. The results indicate that the deflection can be divided in a part depending on the load and a part that is a permanent deflection. Based on the results, it can be judged whether blades need to be rejected because of a too large deflection.

UDIMET L-605

Alloy Digest ◽  
2004 ◽  
Vol 53 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Gas Turbine ◽  
Oxidation Resistance ◽  
Turbine Blades ◽  
Heat Treating ◽  
Gas Turbine Blades ◽  
Temperature Performance

Abstract Udimet L-605 is a high-temperature aerospace alloy with excellent strength and oxidation resistance. It is used in applications such as gas turbine blades and combustion area parts. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: CO-109. Producer or source: Special Metals Corporation.

MULTIDIMENSIONAL MANAGEMENT CONTEMPORARY: GENERATION OF SOCIAL MEANINGS FOR A NEW COLLECTIVE IDENTITIES

2018 ◽  
Vol 1 (14) ◽  
pp. 264-273
Author(s):  
Inna Andriivna Semenets-Orlova ◽  
Yaroslava Yaroslavivna Kyselova
Keyword(s):  
Social Activity ◽  
Professional Activity ◽  
Collective Identities ◽  
Dominant Type ◽  
Civil Responsibility ◽  
European Area ◽  
Social Meanings ◽  
Characteristic Features ◽  
Decentralization Reform ◽  
The Individual

The article is devoted to the analysis of the process of generating social meanings on the area of European civilization. Authors assign a separate place to the research of the tendency of increasing social activity in local communities, which accompanies decentralization processes in modern Ukraine. The article analyzes the characteristic features of non-tribes, based on the M. Maffesoli’s concept of “neo-tribalism”, and traces the tendency of reactualization a partly transformed communal way of life of modern tribes. The authors investigate the retrieval of the request for a valuable education in society. It is emphasized on the growing tendency of the filling of the meaning of the professional activity of public administrators, according to the significant request of providing public interests and collective goals by citizens. The authors singled out a new role of public administration — providing public education. In the context of this problem, the authors substantiate the critical need for a successful completion of the authority decentralization reform in Ukraine. Proceeding from the process of neo-tribalism that covers modern Europe, the authors predict the emergence of a new collective identities on the European area. The authors point to a characteristic tendency: Ukrainians are deeply embedded in solving internal problems of society, which manifests in the correction of gaps in cultural and educational policies of past years, self-organization (through volunteer and volunteer movements), civil responsibility for the welfare of their communities, and participation in the management of local affairs. According to the authors, this tendency influences the dominant type of future sociality (it is not the individual “Me”, but “Me as a part of community”).

Optical data signals in fiber optic communication links with fading

2019 ◽  
pp. 94-104
Author(s):  
I. Juwiler ◽  
I. Bronfman ◽  
N. Blaunstein
Keyword(s):  
Spectral Efficiency ◽  
Fiber Optic ◽  
Fiber Optic Cable ◽  
Optical Signals ◽  
Dispersion Properties ◽  
Optical Cable ◽  
Time Dispersion ◽  
Communication Links ◽  
Fiber Optic Communication ◽  
Optic Communication

Introduction: This article is based on the recent research work in the field of two subjects: signal data parameters in fiber optic communication links, and dispersive properties of optical signals caused by non-homogeneous material phenomena and multimode propagation of optical signals in such kinds of wired links.Purpose: Studying multimode dispersion by analyzing the propagation of guiding optical waves along a fiber optic cable with various refractive index profiles of the inner optical cable (core) relative to the outer cladding, as well as dispersion properties of a fiber optic cable due to inhomogeneous nature of the cladding along the cable, for two types of signal code sequences transmitted via the cable: return-to-zero and non-return-to-zero ones.Methods: Dispersion properties of multimode propagation inside a fiber optic cable are analyzed with an advanced 3D model of optical wave propagation in a given guiding structure. The effects of multimodal dispersion and material dispersion causing the optical signal delay spread along the cable were investigated analytically and numerically.Results: Time dispersion properties were obtained and graphically illustrated for two kinds of fiber optic structures with different refractive index profiles. The dispersion was caused by multimode (e.g. multi-ray) propagation and by the inhomogeneous nature of the material along the cable. Their effect on the capacity and spectral efficiency of a data signal stream passing through such a guiding optical structure is illustrated for arbitrary refractive indices of the inner (core) and outer (cladding) elements of the optical cable. A new methodology is introduced for finding and evaluating the effects of time dispersion of optical signals propagating in fiber optic structures of various kinds. An algorithm is proposed for estimating the spectral efficiency loss measured in bits per second per Hertz per each kilometer along the cable, for arbitrary presentation of the code signals in the data stream, non-return-to zero or return-to-zero ones. All practical tests are illustrated by MATLAB utility.

High-Temperature, High-Bandwidth Fiber Optic Pressure and Temperature Sensors for Gas Turbine Applications

2004 ◽  
Author(s):  
Robert Fielder ◽  
Matthew Palmer ◽  
Wing Ng ◽  
Matthew Davis ◽  
Aditya Ringshia
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Fiber Optic ◽  
Temperature Sensors ◽  
High Bandwidth

Improving Efficiency in Robot Assisted Belt Grinding of High Performance Materials

2014 ◽  
Vol 907 ◽  
pp. 139-149 ◽  
Author(s):  
Eckart Uhlmann ◽  
Florian Heitmüller
Keyword(s):  
Gas Turbines ◽  
High Performance ◽  
Scale Effects ◽  
Turbine Blades ◽  
Repair Process ◽  
Industrial Robots ◽  
Robot Assisted ◽  
Belt Grinding ◽  
Economy Of Scale ◽  
The Individual

In gas turbines and turbo jet engines, high performance materials such as nickel-based alloys are widely used for blades and vanes. In the case of repair, finishing of complex turbine blades made of high performance materials is carried out predominantly manually. The repair process is therefore quite time consuming. And the costs of presently available repair strategies, especially for integrated parts, are high, due to the individual process planning and great amount of manually performed work steps. Moreover, there are severe risks of partial damage during manually conducted repair. All that leads to the fact that economy of scale effects remain widely unused for repair tasks, although the piece number of components to be repaired is increasing significantly. In the future, a persistent automation of the repair process chain should be achieved by developing adaptive robot assisted finishing strategies. The goal of this research is to use the automation potential for repair tasks by developing a technology that enables industrial robots to re-contour turbine blades via force controlled belt grinding.

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