Determination of the Flame Front Speed on Sensor’s Signals of Distributed Electro-Optical System

The article is devoted to the development of a method for determining of a flame speed according to signals of electro-optical flame detectors. Analytical dependencies are formulated for the calculation of the flame front speed by the time-of-flight method with the determination of the time delay by four methods: threshold method; method on the basis of the cross-correlation function; method based on the envelope correlation coefficient; method based on cross-spectral density. The results of study of the proposed methods for accuracy of the time delay determining for the simulated noisy signals and for the characteristic experimental signals obtained by recording radiation of non-stationary combustion are presented. The method based on the cross-correlation function is optimal for the implementation of the system. The influence of the analysis time range of the detector signals on the error in determining the time delay was estimated. Criteria for selecting the lower and upper boundaries of the time window were formulated. Algorithm for determining of the flame front speed from the signals of electro-optical flame detectors is proposed.