Facilities: High Pressure Shock Tube (HPST)

Built in 1995, this shock tube is designed for high purity, high-pressure kinetics experiments up to 1000 atm in the reflected shock region. The uniqueness of the apparatus has lead to much development in the way of shock tube design, optical diagnostics, shock tube characterization, and exploration of real gas effects at high pressures. Spectroscopic experiments have included the measurement of the absorption and pressure-broadening coefficient of the OH bandhead near 306nm at pressures up to 60 atm. The equation of state of Ar was investigated for pressures up to 300 atm, using a CO emission diagnostic. We have studied ignition delay times of methane/oxygen mixtures and developed mechanistic models for ignition delay, with particular application to RAM accelerator conditions. A variety of individual reactions have been studied through the extensive use of emission and laser absorption diagnostics. Some species which have been measured include OH, CH, CH3, CH4, H2O, NO2, N2O, and CO.

The driven end of the high pressure shock tube, showing the 2.3 metric ton inertial mass and optical table for laser and other diagnostics.

Looking down the shock tube from the test section (driven end). On the left side is the vacuum pumping system, and at the far end is the high pressure driver. This picture was taken not too long after initial construction.