Applicability of the ZND Detonation Model to Vapor Explosions

Abstract

Thermal detonation theory, has been increasingly applied to vapor explosions. However, there are many questions and interrogations in previous works due to the lack of detailed explanation of the basis of the calculations and due to the incomplete interpretations or internally inconsistent discussions. Therefore, the present study calculates the Hugoniot curves for water and CFCl2 systems to discuss again the applicability of the ZND detonation model to vapor explosion. The results reveal that a solution of detonation may be obtained in a wide range of initial void fraction if steady, one-dimensional and homogeneous two-phase flow is assumed. Three types of solution of C-J point can be obtained, depending on the initial void fraction: the two-phase condition, the kink-point condition and the condensed-phase condition. However, the assumptions involved in the two-phase condition and the condensed phase condition solutions are not always satisfied. On the other hand, the kink-point condition, which has been often excluded from the discussion in previous works, provides a solution that may be actualized.