A scramjet engine is expected as an engine which can be applied to a future space transportation system. Many technical challenges still exist, one of which is to establish a measurement method to observe flow and combustion states within the scramjet engine. The TDLAS measurement method, capable to measure distribution of concentration, was applied to a supersonic reacted flow simulating the inner flow of a scramjet engine in our previous research. However, the errors were 19.3% and 18.4% in temperature and concentration measurements, respectively. Therefore, improvement on the measurement accuracy of TDLAS using two-line technique was attempted in the present study. The TDLAS was applied to a double diaphragms shock tube experiment for calibration, resulting in reduced error of temperature measurements to 80 K from 250 K in the previous study with a flat flame burner. After that, the distribution measurement in a supersonic reacted flow was implemented using TDLAS. In conclusion, the errors of temperature and concentration measurements were improved to 12% and –3%, respectively.
View full abstract