A quantitative analysis of Schlieren photographs for internal combustion engine diagnostics. 2nd Report, smoothing of background distortion and analytical results of transient wall-impinging jet.

Abstract

The first report showed the quantitative analysis method of Schlieren photographs and some techniques necessary for eliminating integrated error. However, distortion in the analyzed results due to a non-uniform background level still remains a major difficulty. This report describes a method for removing distortion caused by the background. It also provides an example of analyzed results for a CO2 jet impinging on a wall. The results show that the correction technique is effective, and that the analysis technique can be one of the available diagnostic methods for internal combustion engine research.