High-pressure gas temperature sensing for exit plane of aero-engine combustor using tunable diode laser absorption spectroscopy

We have developed a sensor for the temperature measurement in the test section after the combustion chamber of an aero engine model by using direct absorption spectroscopy. Five distributed feedback diode lasers at near 1392, 1393, 1339, 1343, and 1469 nm are utilized as the light sources to detect H2O absorptions to improve the precision of temperature measurement combining with the Boltzmann plot method and the polynomial-based spectral fitting model. The sensor shows a good performance in terms of its temperature measurement accuracy under high temperature of 673-1373 K and high pressure of 100-600 kPa condition in a tube furnace, which was lower than 4%. Moreover, three-dimensional temperature distributions have been reconstructed via applying algebraic reconstruction technique at the test section after the combustion chamber of an aero engine model. The single-point position temperature extracted from the algebraic reconstruction technique agrees well with that measured from the coherent anti-stokes Raman scattering technique, where the relative error is within 5%. All the above results prove the reliability of our developed temperature sensor.