HIGH-PURITY SHOCK TUBE (HPST)
The high-purity shock tube (HPST), built in 1992 and initially designed for use with H-atom ARAS technique, has been converted as part of the FUN-PM project to single-pulse operation for stable species measurements behind reflected shock waves. The shock tube is characterized by a driven section with inner diameter of 78 mm and length of 6 m, separated from the driver section (120 mm inner diameter and 3.7 m length) by a double diaphragm section. A 150 L dump tank is placed close to the diaphragm section on the driven section side. The HPST can attain pressures up to 60 bar behind the reflected shock waves, with nominal reaction times of 4 ms. An air-actuated valve is mounted at the center of the endwall for gas sampling. A new analytical section composed of two gas chromatographs (one with a novel design specifically dedicated to the measurement of polycyclic aromatic hydrocarbons (PAHs)) and one mass spectrometer was set-up for measurement of small C1-C6 intermediates, PAH compounds up to 4-ring size, O2, CO, CO2 and noble gases. The HPST facility has been mainly used to study the highly-diluted pyrolysis of aromatic fuels and their mixtures with small aliphatic components and the related PAH formation chemistry.