Formation Of Detonation Waves In Hydrogen Oxygen Mixtures From 02 To 2 Atmospheres Initial Pressure In A 54 Meter Long Tube

Detonation induction distances were measured in hydrogen-oxygen and methane-oxygen mixtures flowing at various velocities through a 9 stainless steel tube, 9 mm inside diam. The linear flow velocities of the gas mixture ranged from 0-100 m/sec in hydrogen-oxygen mixtures. Some experiments were conducted at 5 atm initial pressure. Experiments with methane-oxygen mixtures were carried out at 1 atm only; the initial velocities of these mixtures ranged from 0-30 m/sec. It was found that the formation of detonation waves in flowing combustible gaseous mixtures is dependent upon the initial pressure and the intensity of turbulence present in the gases. As the initial pressure is raised, the effect of turbulence becomes less pronounced. Higher turbulence levels cause an effective decrease in the quenching diam as indicated in these experiments. Higher flow rates for a methane-oxygen mixture (50 per cent fuel) insure positive ignition and positive measurement of flame propagation rates. (Author).

Detonation induction distances were determined in a 9-mm inside diameter detonation tube at an initial pressure of 1 atm at ambient initial temperature for hydrogen-oxygen mixtures flowing at initial velocities ranging from 1-100 meters/second and for methane-oxygen mixtures flowing at velocities ranging from 0-30 meters/second. Some experiments with hydrogen-oxygen mixtures were conducted at 5 atm initial pressure. The results show that the induction distances for hydrogen-oxygen mixtures decrease linearly with the logarithm of the Reynolds number based on the initial linear gas velocity. The induction distance of the detonation wave propagating upstream is shorter than that of the wave propagating downstream. Induction distances in methane-oxygen mixtures were essentially constant over the range of flow velocities employed. Certain observations seem to indicate that higher turbulence levels in the initial gas flow cause an effective decrease in the quenching diameter. (Author).