Tip timing measurements using fiber optic sensors

Tip timing measurements using fiber optic sensors.

The challenge
Approaching multifiber links in very high-temperature and highly vibrating turbine environments.

Major constraints

  • high-temperatures: > +600 °C
  • mechanical stress: chocs, vibrations, low bend radius

SEDI-ATI solution
Optical probes consisting in bundle assemblies of optical fibers resistant to +600 °C, and soldered at the tip.

Advantages of the SEDI-ATI solution
Our fiber assemblies withstand engine and turboshafts testing conditions.

Tip timing measurements using fiber optic sensors

SEDI-ATI offers fiber optic sensors consisting of bundles of optical fibers resistant to +600 °C in order to perform tip timing measurements during engine tests.

Turbine blades are critical parts of aeronautic engines. They are subjected to high mechanical stresses at very high temperatures. In the event of breakage, the integrity of the engine, or even of the aircraft, can be compromised.

Tip-timing is involved in the qualification of engines and turboshafts. This technique enables to monitor the vibratory modes of turbine blades in operation and to detect possible blade deformations.

The campaign of tests consists in mounting optical sensors on the engine casing, in front of the blades, in order to measure their time of passage. The amplitude of vibration of each blade as it passes in front of the sensors can be deducted from the passage times of the blades and the speed of rotation.

The optical measurement is carried out by a photon emission/reception principle. Emitting fibers are used to illuminate the blades. The reflection on the blades is captured by the collecting fibers placed around the emitting fibers. The optical signals are then analyzed using specific algorithms.

In aircraft engines, turbine blades are parts that operate at very high temperatures. SEDI-ATI designs quality optical probes that can withstand 600 °C.