论文部分内容阅读
An experimental system based on the background-oriented schlieren (BOS) technique is built to reconstruct the density and temperature distribution of a flame-induced distorted flow field which has a density gradient.The cross-correlation algorithm with sub-pixel accuracy is introduced and used to calculate the background-element displacement of a disturbed image and a fourth-order difference scheme is also developed to solve the Poisson equation.An experiment for a disturbed flow field caused by a buing candle is performed to validate the built BOS system and the results indicate that density and temperature distribution of the disturbed flow field can be reconstructed accurately.A notable conclusion is that in order to make the reconstructed results have a satisfactory accuracy,the inquiry step length should be less than the size of the interrogation window.