Development of an Experimental Capability to Produce Controlled Blade Tip∕Shroud Rubs at Engine Speed

2004 ◽  
Vol 127 (4) ◽  
pp. 726-735 ◽  
Author(s):  
Corso Padova ◽  
Jeffrey Barton ◽  
Michael G. Dunn ◽  
Steve Manwaring ◽  
Gamaliel Young ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Engine Speed ◽  
Gas Turbine Engine ◽  
Specific Information ◽  
Bladed Disks ◽  
Turbine Engine ◽  
Blade Tip ◽  
Tip Shroud ◽  
Compressor Disk

An experimental capability using an in-ground spin-pit facility specifically designed to investigate aeromechanic phenomena for gas turbine engine hardware rotating at engine speed is demonstrated herein to obtain specific information related to prediction and modeling of blade-casing interactions. Experiments are designed to allow insertion of a segment of engine casing into the path of single-bladed or multiple-bladed disks. In the current facility configuration, a 90deg sector of a representative engine casing is forced to rub the tip of a single-bladed compressor disk for a selected number of rubs with predetermined blade incursion into the casing at rotational speeds in the vicinity of 20,000rpm.

Development of an Experimental Capability to Produce Controlled Blade Tip/Shroud Rubs at Engine Speed

2004 ◽  
Author(s):  
Corso Padova ◽  
Jeffery Barton ◽  
Michael G. Dunn ◽  
Steve Manwaring ◽  
Gamaliel Young ◽  
...  
Keyword(s):  
Engine Speed ◽  
Facility Design ◽  
Bladed Disks ◽  
Current Configuration ◽  
Blade Tip ◽  
Design Speed ◽  
Tip Shroud ◽  
Compressor Disk

Development of an in-ground spin-pit facility specifically designed to investigate aeromechanic phenomena for engine hardware rotating at design speed is reported in this paper. The purpose of this paper is to describe the facility design and operation and to demonstrate utility by providing typical results from a recently completed measurement program. The facility is designed to allow insertion of a segment of engine casing into the path of single-bladed or multiple-bladed disks. In the current configuration, a 90-degree sector of a representative engine casing is forced to rub the tip of a single-bladed compressor disk with predetermined blade incursion into the casing for rotational speeds in the vicinity of 20,000 rpm.

The Development and Testing of a Gas Turbine Engine Foreign Object Damage (FOD) Detection System

2010 ◽  
Author(s):  
D. N. Cardwell ◽  
K. S. Chana ◽  
M. T. Gilboy
Keyword(s):  
Gas Turbine ◽  
Eddy Current ◽  
Engine Speed ◽  
Detection System ◽  
Acoustic Emissions ◽  
Gas Turbine Engine ◽  
Current Sensor ◽  
Foreign Object ◽  
Turbine Engine ◽  
Foreign Object Damage

This paper details the development of a prototype in-flight foreign object damage (FOD) detection system through various stages, resulting in a system capable of detecting objects as small as one gram (1g) mass. The system comprises an eddy current sensor based tip timing system and acoustic emissions vibration sensors controlled through a digital signal processor (DSP). QinetiQ have developed light weight, contamination-immune eddy current tip timing sensors for use in engine health management. Engine tests confirmed these sensors’ potential for detecting FOD events. FOD detection algorithms were developed and implemented in a prototype DSP that was built and tested on an uninstalled gas turbine engine. The trials showed that the prototype DSP FOD detection system could detect dynamic FOD events at full engine speed. Further work was carried out to enhance the FOD detection system, overcoming limitations in the previous system through the implementation of enhanced algorithms and its extension to accept four eddy current sensor inputs as well as a vibration signal input from an acoustic emissions (AE) sensor. An algorithm that computes engine speed from the tip timing data was also implemented to alleviate the need for a separate 1/rev signal. A number of engine trials were successfully completed in order to validate the system. The speed algorithm has been successfully validated on engine trials and comparisons with a conventional optical based 1/rev showed the DSP-generated 1/rev signals to be almost identical to the conventional system. Typically, the error was in the region of 0.03% speed. The investigations culminated in a test series designed to ascertain the system’s sensitivity to foreign object impacts. These demonstrated that the system was capable of detecting objects down to one gram (1g) mass introduced at low speed into the engine intake.

scholarly journals A review of blade tip clearance–measuring technologies for gas turbine engines

2020 ◽  
Vol 53 (3-4) ◽  
pp. 339-357 ◽  
Author(s):  
Bing Yu ◽  
Hongwei Ke ◽  
Enyu Shen ◽  
Tianhong Zhang
Keyword(s):  
Gas Turbine ◽  
Measuring Method ◽  
Gas Turbine Engine ◽  
Tip Clearance ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Turbine Engine ◽  
Blade Tip ◽  
Safety And Stability ◽  
Blade Tip Clearance

Blade tip clearance is one of the important parameters affecting the performance, safety and stability of a gas turbine engine. However, it is difficult to measure the tip clearance in real time and accurately during the development and test process of an engine. In order to promote the development of tip clearance–measuring technology and the optimal design of the gas turbine engine, some typical measuring methods of tip clearance and a novel measuring method based on AC discharge are introduced. In this article, the significance for measuring tip clearance of an engine is illustrated first. Then, operating principles, characteristics and developments of those typical measurement approaches are introduced. After that, these methods are analyzed, and the particular characteristic of each measuring approach is summarized.

Novel resistor-capacitor (RC) network-based capacitance signal conditioning circuit for tip clearance measurement on gas turbine engine

2019 ◽  
Vol 234 (2) ◽  
pp. 342-360
Author(s):  
TN Satish ◽  
A Vivek ◽  
SN Anagha ◽  
ANV Rao ◽  
G Uma ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Direct Current ◽  
Gas Turbines ◽  
Signal To Noise Ratio ◽  
Gas Turbine Engine ◽  
Rotor Blades ◽  
Tip Clearance ◽  
Turbine Engine ◽  
Blade Tip ◽  
Conditioning Circuit

Blade tip clearance is a critical engine health parameter measured on gas turbines. Increase in tip clearance results in decreased efficiency, whereas with decrease in clearance due to thermal and centrifugal loads, rotor blades might rub the engine case. Various sensing techniques are being used, among them, capacitance-based systems are widely used by many engine houses. Among the capacitance conditioning circuits, resistor-capacitor series network-based circuits are simple to implement but pose many challenges during practical development. During the current work, the authors have designed a novel capacitance conditioning circuit combining resistor-capacitor series network, instrumentation amplifiers, and direct current–direct current converters. Performance of the developed capacitance conditioning electronics was evaluated through lab testing and tip clearance measurement on fan stage of an aero gas turbine engine. The prototype conditioner circuit has efficiently conditioned and resolved small capacitances varying from 1.25 pF to 0.00413 pF for running clearances between 0.4 mm and 3 mm, respectively. The developed electronics produced high output with signal-to-noise ratio of 58.1 dB, resolution of 2.5 µm, bandwidth of about 700 kHz, and an accuracy of about 98%. This development has culminated towards miniaturization of the total electronics and has the potential to get developed as smart capacitance sensor. This paper explains the practical aspects and challenges involved while designing and developing such practical conditioning circuits.

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