VALIDATION OF THE REAL-TIME 2D TEMPERATURE MEASUREMENT METHOD USING THE CT TUNABLE DIODE LASER ABSORPTION SPECTROSCOPY

Two dimensional (2D) temperature and concentration distribution plays an important role for the combustion structure and the combustor efficiency in engines, burners, gas turbines and so on. Recently, as a multi-species measurement technique with high sensitivity and high response, tunable diode laser spectroscopy (TDLAS) has been developed and applied to the actual engine combustions. With these engineering developments, transient phenomena such as start-ups and load changes in engines have been gradually elucidated in various conditions. In this study, the theoretical and experimental research has been conducted in order to develop the non-contact and fast response 2D temperature and concentration distribution measurement method. The method is based on a computed tomography (CT) using absorption spectra of water vapor at 1388 nm. The computed tomography tunable diode laser spectroscopy (CT-TDLAS) method was employed in engine exhausts to measure 2D temperature distribution. The measured 2D temperature shows a good agreement with the temperature measured by a thermocouple. The temporal and spatial resolutions of this method have also been discussed to demonstrate its applicability to various types of combustor.