Laser Induced Grating Spectroscopy (LIGS) measurements taken at the GTRC

GTRC hosted researchers Lee Weller and Priyav Shah from Cambridge University and Oxford University as part of an EPSRC project “Tracer-free, non-intrusive, time- and space-resolved temperature and scalar measurements”, Principal Investigator Simone Hochgreb

The need for low emission combustion technology requires an understanding of the local gas temperature, but in-flame, non-intrusive temperature measurement in pressurised highly radiant flames typically requires complex optical techniques.

LIGS is a non-linear laser optical diagnostic technique which can be used to measure the temperature, pressure or species concentration at a point. The technique uses a pulsed laser to create a laser-induced grating, and a continuous wave laser to measure the transient properties of the grating. LIGS is a robust option for challenging ‘dirty’ environments, excels at elevated pressures and is inexpensive compared to similar diagnostics.

(https://link.springer.com/article/10.1007/s00340-003-1282-8)

This test campaign showed that a LIGS signal could be measured in a 75kWth methane flame at 4bar. Future test campaigns aim to extend this to higher pressures and powers, and provide valuable experimental data to validate combustion models.