Application of H2 and CO2 addition in driver section on shock tube ignition delay measurement.

Shock tube is an effective tool to study the reaction dynamic. As a key parameter, the accuracy measurement of ignition delay time depends on the pressure plateau sustained time. Helium is the most frequently used as driver gas in the shock tube related study. To seek a wider scope of driver gas, H2 was attempted in this paper. The driver capability of H2 and He was compared by theory analysis and experiment, respectively. In addition, to acquire a longer test time, H2/CO2 as driver gas was adopted to test the tailoring condition. Using a 1‐D ideal shock tube assumption, the driver gas tailoring curve is calculated. Results show that the driver capability of H2 is obviously stronger than that of He gas and H2/CO2 group driver gas performs as well as He/N2 group driver gas. The pressure plateau sustained time can extend to 11 ms under tailoring condition by H2/CO2 mixture driving. Furthermore, the comparison of H2‐based and He‐based driver gas models shows no obvious impact on ignition delay measurement. Hence, using H2 as driver gas is more economic because of its cheaper price than He, and it can reduce the experiment risk because of the relative lower diaphragm burst pressure. However, the adverse result is that the vacuum time turns more than one third longer compared with non‐H2 driving mode. [ABSTRACT FROM AUTHOR]