A three-dimensional shape descriptor for burner flames

The shape of a burner flame is an important characteristic closely linked to the burner configuration, fuel type, and other operational parameters of a combustion process. This paper presents an algorithm to extract the 3-D medial axis of a burner flame and use it as a descriptor for the flame shape characterization. The algorithm is based on the 2-D medial axes of two flame images captured from two orthogonal directions of the burner using a flame imaging system. Since the data of the extracted features are much less than those of the original image, the computing process is simplified and efficient. Experimental results demonstrate that the flame 3-D medial axis determined using the proposed algorithm reflects its dynamical movement. Together with the radial parameter of the defined medial axis, a range of 3-D geometric parameters of the flame can be estimated.