Measuring Temperature of Reflected Shock Wave Using a Standard Chemical Reaction

Abstract

The importance of temperature calibration of a single pulseshock tube for obtaining precise kinetics data is well recognized. Someof the commonly used standard reactions for chemical thermometricmeasurements and their uses in our recent studies are discussed in thisarticle. The chemical standards listed include cyclopropane-carbonitrile,1,1,1-trifluoroethane, cyclohexene, and ethyl chloride. A recent temperaturecalibration study of one of our chemical shock tubes performed using ethylchloride as external standard for the temperature range from 982–1183 Kis presented. The reflected shock temperatures calculated using machnumber, 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 calibrationdata where the corresponding difference was in the range ~8–14 %. Thedifference in the calibration factor is due to the various changes made inthe shock tube and it highlights the importance of calibration, if and whenthe shock tube is modified.