Underwater explosion research using small amounts of chemical explosives

Underwater explosions have found extensive application in technology, acoustics and physics. Most investigations using underwater explosions are performed as full-scale tests, this is mainly due to the widely held view that reliable measurements of pressure waves taken at a short range from the detonation of small amounts of chemical explosives are extremely difficult, if not impossible, to perform. On the basis of a number of tests where small amounts of explosives, ranging from 0.2 to 6 g were detonated, the scaling law for underwater explosion shock waves was generalized and includes short distances and very small charge weights typical of laboratory conditions. Empirical expressions for the peak pressure, time constant, impulse and energy flux density as a function of charge weight and distance have been worked out. Excellent agreement was found between the peak pressures calculated using the empirical expression and the corresponding values calculated using Kirkwood - Bethe's theory for underwater shock waves. Various scaling effects, which if not realized may lead to erroneous results, are emphasized. It is concluded that small scale (laboratory) underwater explosion tests, give valid useful results and may be used instead of traditional full scale tests in a number of fields.