Reacting Flows

LIGS

Laser induced grating spectroscopy (LIGS) has been used to determine temperatures in the products of flames with high precision. The technique uses a pulsed beam at 1064 nm to excite weak water molecule lines to produce a density grating and an associated pressure pulse. The resulting density pattern is probed using a continuous wave laser.

The particular advantages of the 1064 nm LIGS are :

  • the very high precision which arises from the measurement of a frequency.
  • easily available excitation line with high energies from Nd:YAG lasers
  • can be used to excite electrostrictive modes to obtain temperatures in reactants or products

The current version of the technique offers suffcient signal from 3 bar upwards for measurement of product temperatures.

Ringing pattern obtained using LIGS

Temperatures measured using LIGS

Last updated on 1 Jan 0001