Application of Fourier descriptors to combustion diagnostics

W artykule przedstawiono wykorzystanie deskryptorów Fouriera opisujących kształt płomienia do określenia stabilności płomienia pyłowego. Badania wykonywane były na stanowisku laboratoryjnym, w czasie których zmieniano wydatki powietrza pierwotnego, wtórnego oraz pyłu węglowego doprowadzając do utraty stabilności płomienia.The paper presents the application of Fourier descriptors of the flame shape to assessment of the pulverised coal flame stability. Experiments were made on a laboratory stand equipped with a scaled down 1:10 swirl burner, while flows of the primary, secondary air as well as coal were changed. It caused lack of the flame stability, which could be observed through the changing flame shape. Flame images were captured by a monochrome CCD camera, mounted in an inspection opening, as shown in Fig. 1. Since the flame was the only luminous object, determination of its area and edge was based on a pixel amplitude. The flame edge was transformed into Fourier descriptors and was a subject of investigation