2ème atelier international
J. Phys. IV France 05 (1995) C4-231-C4-257
A Comparison of the Classical and a Modern Theory of DetonationF.E. Walker
Interplay, Danville, California 94526, U.S.A.
A quite complete exposition of what has been called the classical theory of detonation is given in the Scientific American of May 1987 by W.C. Davis. However, Davis states in his report that, "In spite of the variety of modern applications of explosives, detonation science has not yet reached maturity...," and, "Scientists who study explosions are spurred on by being constantly reminded that the current detonation theory is incomplete." In this paper a comparison is made between the classical theory as expounded by Davis and a more modern theory based on the concepts that : (1) The energy in the very narrow shock or detonation front is highly nonergodic, and thermal equilibrium, particularly between the translational and vibrational energy modes, does not exist in the front ; (2) No realistic temperature can be ascribed to this very narrow zone ; and (3) A physical regulator which constrains shock and detonation velocities is directly related to the vibratory velocities of the atoms of the shocked materials. The paper includes a short historical summary, a statement of some crucial deficiencies in the classical theory, and it contains the presentation and discussion of a number of experiments and mathematical arguments favoring the alternative theory. Among these are experimental observations made in the 1960s and 1970s and continuing to the present. Proposals of tribochemical or mechanical bond fracture in shock fronts in explosives were made as early as 1938, and they appeared occasionally in later years, but they were often ignored. Finally, results from more recent experiments and calculations are summarized, which appear to support forcefully the alternative theory.
© EDP Sciences 1995