Experimental Research on the Detonation in Gaseous Mixtures with Suspended Aluminum Particles

The experiments have been performed in a horizontal detonation tube having a 13-m-long test section with 224 mm internal diameter. The suspended aluminum particles are spherical with a diameter range of 1–50 μm, using a particle concentration of 300 g/m³ approximately. It is found that the single-front and double-front detonation waves can propagate in a mixture of φ = 1.0 H₂–air and aluminum particles which react with water vapor produced by gaseous detonation. The pressure records show that the detonation structure is double front when using 50 or 30 μm aluminum particles and that single front when using 20, 10, or 1 μm ones. However, these single-front detonation waves don’t have the same properties. The detonation velocity using 1 μm particles is increased by 3.3% from the value of the baseline gas detonation as the heat release between particles and gases starts before the sonic surface and supports the shock, while the 10 and 20 μm ones start behind the sonic surface, so the detonation velocities cannot be increased. The single-front structure displayed in pressure records using 10 and 20 μm particles is because of the delay of the second front which is too short to distinguish in the pressure records.