Citation:
Craig P. Lawson and Paul C. Ivey, Tubomachinery blade vibration amplitude
measurement through tip timing with capacitance tip clearance probes, Sensors
and Actuators A: Physical, Volume 118, Issue 1, 31 January 2005, Pages 14-24.
Abstract:
Turbomachinery blade vibrations can cause High Cycle Fatigue, which reduces
blade life. In order to observe this vibration a nonintrusive monitoring system
is sought. The vibration can be detected by measuring blade tip timing since in
the presence of vibration the blade timing will differ slightly from the passing
time calculated from rotor speed. Much research and development has gone into
investigating the ability of optical probes to achieve this. However, this paper
looks at the potential for a dual use capacitance probe sensor to measure both
tip timing and tip clearance. This paper provides new insights into the ability
of a commercially available capacitance probe tip clearance measurement system
for application as a non-intrusive turbomachinery blade tip timing measurement
device. This is done by correlating capacitance probe tip timing results with
simultaneously measured blade-mounted strain gauge vibration results and precise
rotational speeds. Blade tip vibration amplitudes are measured using capacitance
probes and compared to strain derived vibration levels. Thus the
characterisation and quantification of the performance of the capacitance probe
system when measuring blade vibration on a full-sized low-speed research
compressor is analysed and reported.