Experimental Study of Premixed Flame Methane-Air using a Fine Wire Compensed Thermometry

An experimental procedure with post processing to measure the temperature fields in premixed turbulent flame is presented. Temperature measurements were performed on turbulent premixed flame CH4-air with an equivalence ratio phi = 0.6 divided by 1.3. It utilizes the Fine Wire Compensated Thermometry (FWCT) technique. Using fine wire thermocouples for a temporal resolution of the measurement in high temperature requires specific treatment of these values. When the temperature of the environment is high, the radiant loss becomes important. The temperature measured by the hot junction is less than the environment temperature. These losses are estimated by one model, which make it possible to correct the difference between thermocouple temperature and gas temperature. Temperature measure by Fine Wire Compensated Thermocouple requires knowledge of flow velocity, the experimental conditions, the acquisition parameters (sampling frequency) for post-processing. In addition to this, the catalytic effect was incorporated to the final balance equation. The flame temperature and its fluctuations are analyzed by digital processing algorithms. Measurements validation made by the FWCT technique with optical measurement methods (Rayleigh scattering) shows a good agreement.