COMBUSTION-DETONATION TRANSITION OF A POWDERED EXPLOSIVE LAYER IN A LARGE SIZED TUBE

Experiments are carried out on the combustion-detonation transition of freely-poured layers of hexogen, octogen, and TEN, as well as mixtures of hexogen with concentrated nitric acid and octogen with acetone in tubes up to 7 m long with diameters up to 0.094 m. Calculations are performed and the asymptotic combustion-detonation transition condition is obtained in the form of the limiting tube length at which the velocity of the gas flow with suspended burning explosive particles becomes infinite. The value of the Reynolds number at the tube output is determined for constant combustion surface. It is shown that for Re > 11,500 at sufficiently high explosive layer thickness the transition occurs practically without fail.