Experimental Investigation of Aerodynamic Performance due to Blade Tip Clearance in a Gas Turbine Rotor Cascade

2022 ◽  
Vol 31 (1) ◽  
pp. 173-178
Author(s):  
Jinmoo Chung ◽  
Seungchan Baek ◽  
Wontae Hwang
Keyword(s):  
Experimental Investigation ◽  
Gas Turbine ◽  
Turbine Rotor ◽  
Aerodynamic Performance ◽  
Tip Clearance ◽  
Blade Tip ◽  
Blade Tip Clearance

A Blade by Blade Tip Clearance Measurement System for Gas Turbine Applications

1994 ◽  
Author(s):  
A. G. Sheard ◽  
B. Killeen
Keyword(s):  
Gas Turbine ◽  
Measurement System ◽  
System Reliability ◽  
System Performance ◽  
Tip Clearance ◽  
Test Facility ◽  
Hostile Environment ◽  
Reliable Measurement ◽  
Blade Tip ◽  
Blade Tip Clearance

It is difficult to make a reliable measurement of running clearance in the hostile environment over the blading of a modern gas turbine. When engine manufacturers require the measurement to be made over every blade during live engine tests, system reliability, ruggedness and ease of operation are of primary importance. This paper describes a tip clearance measurement system that can measure clearance over every blade around a rotor. The measurement system concept is presented, and the system design described in detail. Commissioning of the measurement system on a compressor test facility, and the results obtained are discussed. An analysis of system performance during the commissioning trials concludes the paper.

scholarly journals Blade by Blade Tip Clearance Measurement

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
A. G. Sheard
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Measurement System ◽  
Measurement Techniques ◽  
Tip Clearance ◽  
Initial Development ◽  
Real World Applications ◽  
Blade Tip ◽  
Capacitance Probe ◽  
Blade Tip Clearance

This paper describes a capacitance-based tip clearance measurement system which engineers have used in the most demanding turbine test applications. The capacitance probe has survived extended use in a major European gas turbine manufacturer's high-temperature demonstrator unit, where it functioned reliably at a turbine entry temperature in excess of 1800 degrees Kelvin. This paper explores blade by blade tip clearance measurement techniques and examines probe performance under laboratory conditions in support of high-temperature installations. The paper outlines the blade by blade tip clearance measurement technique and describes the experimental facility used to study tip clearance measurement. The paper also fully describes the method used to calibrate the measurement system in order to ascertain measurement accuracy. The paper clarifies how the practical problems were overcome associated with making blade by blade tip clearance measurements in both compressor and turbine environments. Since its initial development, gas turbine development programmes have routinely used the clearance measurement system. The inherent robustness of the system has resulted in reliable in-service measurement of clearance in real world applications.

Turbine Blade Tip Clearance Measurement Utilizing Borescope Photography

1978 ◽  
Author(s):  
A. L. Chandler ◽  
A. R. Finkelstein
Keyword(s):  
Fiber Optics ◽  
Dimensional Analysis ◽  
Turbine Blade ◽  
Test Procedure ◽  
Turbine Rotor ◽  
Tip Clearance ◽  
Blade Tip ◽  
Blade Tip Clearance

In this paper, a technique is presented for the detrmination of turbine rotor bade tip-to-stationary shroud clearance requirements utilizing fiber optics. To accomplish these tip clearance determinations, special rub pins were installed in the turbine shrouds, or tip-shoes, of a 10,000-hp engine. A test procedure was created based upon a transient dimensional analysis, and a cooled borescope and camera were developed. The clearances are presented from a series of successive engine tests.

scholarly journals Microwave Blade Tip Clearance Measurement System

1996 ◽  
Author(s):  
Richard Grzybowski ◽  
George Foyt ◽  
Hartwig Knoell ◽  
William Atkinson ◽  
Josef Wenger
Keyword(s):  
Gas Turbine ◽  
Measurement System ◽  
Ceramic Materials ◽  
Tip Clearance ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Phase Measurements ◽  
Blade Tip ◽  
Clearance Control ◽  
Blade Tip Clearance

This paper describes the development of a Microwave Tip Clearance Measurement System for use in the gas turbine environment Applications for this sensor include basic tip clearance measurements, seal wear measurement and active blade tip clearance control in gas turbine engines. The system being developed was designed for useful operation to temperatures exceeding 1093°F, since only ceramic materials are directly exposed in the gas path. Other advantages of this microwave approach to blade tip clearance sensing include the existence of an inherent self-calibration in the sensor that permits accurate operation despite temperature variations and possible abrasion by the rotating blades. Earlier experiments designed to simulate this abrasion of the sensor head indicated that rubs as deep as 1 mm (40 mils) were easily tolerated. In addition, unlike methods based upon phase measurements, this method is very insensitive to cable vibration and length variations. Finally, this microwave technique is expected to be insensitive to fuel and other engine contamination, since it is based on the measurement of resonant frequencies, which are only slightly affected by moderate values of loss due to contamination.

scholarly journals Blade Tips - Clearance and Its Control

2013 ◽  
Vol 135 (08) ◽  
pp. 66-71
Author(s):  
Lee S. Langston
Keyword(s):  
Gas Turbine ◽  
Response Times ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Thermally Induced ◽  
Turbine Efficiency ◽  
Blade Tip ◽  
Different Response ◽  
Transient Operations ◽  
Blade Tip Clearance

This article focuses on studying blade tip clearance phenomena. It is important to realize that to be freely turning, a blade (or a cantilevered stator) must have a clearance gap between its tip and the engine casing (or hub). Such clearances introduce aerodynamic losses, decreasing gas turbine efficiency. Tip leakage losses in compressors can be significant and have been reviewed by the experts. During transient operations, gas turbine blade tip clearances will change based on blade/disk centrifugal loads and the different response times of engine parts to thermally induced expansions and contractions. Designers have perfected active clearance control (ACC) systems to deal with these transient conditions. ACC uses cool or hot gas path and fan air at appropriate times during transients to control the rate of expansion or contraction of internal parts adjacent to the gas path and outer casings. The research shows that continued enhancement of blade tip clearance management systems over a range of engine operating conditions has brought and will bring about gains in gas turbine efficiency.

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