Task 4.3: Temperature measurement with new generation of optical fibres
This task will develop a new instrument for the measurement of temperature fields in combustion systems. It will be based on an emerging technology: a photonic crystal fibre (PCF) with a hollow core containing a micro-bead (Bykov et al 2015). The bead is the primary sensor. It is propelled through the hollow core optomechanically. Its motion, which is measured by Doppler velocimetry, depends on the viscosity of the air surrounding the bead in the hollow core, and the viscosity in turn depends on the local temperature. A laboratory test rig will be built to demonstrate this optomechanical system. Its advantages are numerous: the sensor can be operated remotely over several metres, and it is self-calibrating; the fibre is long, but very compact in cross-section; hence it can cover a large detection range without being intrusive; the spatial resolution is high (of the order of 50 µm), the response time is fast (about 50 ms); the operating temperature is expected to exceed 1500K.