Engineering Elements of Explosions
NAVAL WEAPONS CENTER CHINA LAKE CA
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Two rather distinct types of blast are generated in the ordinary atmosphere in a conventional explosion. One is a close-in composite blast that involves both explosion products and air the other is a more remote blast that involves atmospheric air only. These two types of blast are described qualitatively and quantitatively in terms of a reference explosion, chosen here as that of a bare spherical charge of unit mass of TNT in the ordinary atmosphere. The scaling laws for explosions which are geometrically similar are deduced from basic principles, and their limitations carefully outlined. Representative applications are illustrated by numerical examples. The transient nature of blast is one of its important aspects and makes it difficult to establish its damage potential by analytic means in any except the simplest circumstances. Hence, there is still need for semi-empirical methods such as one based on critical impulse delivered within a critical time. Detailed tables for characteristics of blast from reference explosions Appendixes A and B give values for peak overpressure, impulse, decay characteristics, and travel and duration times, all as a function of distance and for both free-field and normal reflection situations.