Measuring temperature of reflected shock wave using a standard chemical reaction

The importance of temperature calibration of a single pulse shock tube for obtaining precise kinetics data is well recognized. Some of the commonly used standard reactions for chemical thermometric measurements and their uses in our recent studies are discussed in this article. The chemical standards listed include cyclopropane-carbonitrile, 1,1,1-trifluoroethane, cyclohexene, and ethyl chloride. A recent temperature calibration study of one of our chemical shock tubes performed using ethyl chloride as external standard for the temperature range from 982-1183 K is presented. The reflected shock temperatures calculated using Mach number, T5(Ms),and those using ethyl chloride as external standard (T5kin) were found to differ by ∼1.3-4.5 % in the studied temperature range. This is an improvement compared to our previously reported calibration data where the corresponding difference was in the range ∼8-14 %. The difference in the calibration factor is due to the various changes made in the shock tube and it highlights the importance of calibration, if and when the shock tube is modified.