Several techniques have been developed for obtaining long, constant-pressure test times in reflected shock wave experiments in a shock tube, including the use of driver inserts, driver gas tailoring, helium gas diaphragm interfaces, driver extensions, and staged driver gas filling. Here, we detail these techniques, including discussion on the most recent strategy, staged driver gas filling. Experiments indicate that this staged filling strategy increases available test time by roughly 20 % relative to single-stage filling of tailored driver gas mixtures, while simultaneously reducing the helium required per shock by up to 85 %. This filling scheme involves firstly mixing a tailored helium-nitrogen mixture in the driver section as in conventional driver filling and, secondly, backfilling a low-speed-of-sound gas such as nitrogen or carbon dioxide from a port close to the end cap of the driver section. Using this staged driver gas filling, in addition to the other techniques listed above, post-reflected shock test times of up to 0.102 s (102 ms) at 524 K and 1.6 atm have been obtained. Spectroscopically based temperature measurements in non-reactive mixtures have confirmed that temperature and pressure conditions remain constant throughout the length of these long test duration trials. Finally, these strategies have been used to measure low-temperature n-heptane ignition delay times.

Mathematical Modelling of Gas-Phase Complex Reaction Systems: Pyrolysis and Combustion, Volume 45, gives an overview of the different steps involved in the development and application of detailed kinetic mechanisms, mainly relating to pyrolysis and combustion processes. The book is divided into two parts that cover the chemistry and kinetic models and then the numerical and statistical methods. It offers a comprehensive coverage of the theory and tools needed, along with the steps necessary for practical and industrial applications. - Details thermochemical properties and "ab initio" calculations of elementary reaction rates - Details kinetic mechanisms of pyrolysis and combustion processes - Explains experimental data for improving reaction models and for kinetic mechanisms assessment - Describes surrogate fuels and molecular reconstruction of hydrocarbon liquid mixtures - Describes pollutant formation in combustion systems - Solves and validates the kinetic mechanisms using numerical and statistical methods - Outlines optimal design of industrial burners and optimization and dynamic control of pyrolysis furnaces - Outlines large eddy simulation of turbulent reacting flows

Shock tube test time limitation due to the premature arrival of the contact surface is analytically investigated for wholly turbulent wall boundary layers. The results are compared with those for wholly laminar wall boundary layers. Working curves are presented for more accurate estimates of test time in specific cases. (Author) -- NTRL website.