ABSTRACT
An analogous situation is often encountered while investigating other physical phenomena. Hence in most modelling cases a question arises concerning the partial fulfilment of similarity criteria, that is, about approximate or incomplete modelling. In the theory of blasting in water and air, as is well known, equations of gas dynamics are used, in which forces of viscosity and mass are not considered. The Navier-Stokes equations are simplified, mainly because only one term related to pressure remains in the right side. A charge dimension, usually the radius of a spherical or cylindrical charge, is taken as a characteristic linear dimension in the theory of blasting. Formulation of the similitude law becomes somewhat complicated if the hydrodynamic fields of fluid generated in blasts of different explosive composition are compared. The energy-based principle has to be relied upon as the basis for similarity. A more generalised approach is possible for selecting the system of non-dimensional parameters in the near-field zone of blast.
