title: Low-coherence interferometric tip-clearance probe.
abstract: We propose an all-fiber, self-calibrating, economical probe that is capable of near-real-time, single-port, simultaneous blade-to-blade tip-clearance measurements with submillimeter accuracy (typically < 100 microm, absolute) in the first stages of a gas turbine. Our probe relies on the interference between backreflected light from the blade tips during the 1-micros blade passage time and a frequency-shifted reference with variable time delay, making use of a low-coherence light source. A single optical fiber of arbitrary length connects the self-contained optics and electronics to the turbine.
authors.affiliation: ETH Zürich, Institute of Fluid Dynamics, Sonneggstrasse 3, Zurich 8092, Switzerland. kempe@ifd.mavt.ethz.ch
authors.forename: Andreas
authors.initials: A
authors.lastname: Kempe
authors.forename: Stefan
authors.initials: S
authors.lastname: Schlamp
authors.forename: Thomas
authors.initials: T
authors.lastname: Rösgen
authors.forename: Ken
authors.initials: K
authors.lastname: Haffner