Temperature and/or Density Measurements of Asymmetrical Flow Fields by Means of the Moire-Schlieren Method : Method of Transformation of Moire-Data and Its Application to the Temperature Measurement of a Combustion Flame from a Rectangular Burner

Abstract

A mathematical method for transforming moire-schlieren data into internal density (and/or temperature) distributions has been presented. The method of transformation, which is applicable to both symmetrical and asymmetrical flow fields, has been deduced by modifying the Maldonado-Olsen's series. The accuracy of the present method was examined with a mathematical model of a density function of the truncated pyramid type. In order to demonstrate its usefulness for asymmetrical flows, temperature distributions in a combustion flame have been measured for a square nozzle. Experimental moire images of the flame were recorded by a video camera, and the integrated light refraction was converted into an internal temperature distribution. The results showed that the temperature profiles in the flame are distinctive owing to the rectangular nozzle, and that the present method is very effective.