Overpressure and Dynamic-Pressure Impulse Resulting from High-Intensity Explosion

Abstract

This paper discusses the overpressure and dynamic-pressure impulses resulting from a disturbance of the air caused by high-intensity explosion. The impulses as functions of distance from the center of explosion are theoretically investigated and compared with the latest available experimental data on explosion. The parameters discussed include an explicit investigation of the definition of the shape and the duraction of the positive and negative phases of both the dynamic pressure and the overpressure impulses. The experimental data are evaluated with the aid of an IBM computer program to calculate the total momentum resulting from the pressure-time profiles of the full-scale explosion tests. Following the theoretical approach of G. Taylor and H. L. Brode, the positive overpressure phase is given by IP+ = K1(W/P0)12/R. The positive dynamic-pressure phase is IQ+ = A(W/P0)1/6/R12×[B + R2(W/P0)12]. The negative overpressure impulse is IP− = K2Pm, and the negative dynamic-pressure impulse is IQ− = CQm. The notations are R the distance from the center of explosion, P0 the initial atmospheric pressure, Pm the minimum overpressure, Qm the minimum dynamic pressure, W the total energy released, and K1, K2, A, B, C are constants to be determined from the experimental data obtained by the Ballistic Research Laboratories.