気体デトネーションを開始源とする平面的爆風の研究 Ｉ 開始エネルギの推定

Abstract

An experimental study has been made of the initiation of planar blast waves by gaseous detonations. The gaseous detonation initiated by DDT process is submitted into a long tube filled with air at various initial pressures. The measurement of decaying process of a produced shock wave indicates that it can be treated as a "plane source" blast wave, although there exists a secondary shock wave, which may be a retonation wave refleCted on an end wall of a driver tube, behind the blast Wave front. As a result, the decays of a propagation Mach number and a peak overpressure of the wave front as a function of a distance from the initiation source and the initial pressure of the medium are found to be described by the quasi-similar theory of the idealized plane source blast wave. Comparing the experimental results with the theory leads to the estimation of an initiation energy of the blast wave. The initiation energies of oxyhydrogen detonations for three different mixture strengthes, three different initial pressures and two different size of the driver tube are estimated to show that about 30-40% of the chemical energy contained initially in the driver tube is used to initiate the blast wave.