DETONATION CELL WIDTHS IN HYDROGEN OXYGEN DILUENT MIXTURES AT LOW INITIAL PRESSURES

Detonation cell widths of hydrogen/oxygen/helium/steam mixtures were d etermined in 15 and 30-cm internal-diameter pipes using the smoked-foi l technique. The investigations were carried out over a range of initi al pressures from 13.3 to 106.6 kPa and at an initial temperature of 1 05 degrees C. The concentration range investigated included hydrogen c oncentrations from 10 to 40 percent and steam concentrations of up to 20 percent. The measured cell widths range from about 1 mm to over 100 mm and were in good agreement with those estimated using the calculat ed values of induction times and postshock gas velocities.