The Ls Method Applied To Three Dimensional Detonation Wave Propagation

The development history of detonation wave propagation is reviewed first in this thesis. Some basic theory model and other contents about detonation wave propagation are introduced. Then the level set method is introduced. By means of this method, the properties of three dimensional detonation waves are studied. The main contents of this thesis includes: the LS equations of three dimensional detonation wave propagation; the numerical solution method of LS equations; the experimental design of multi-point initiation; the numerical simulation results of detonation wave propagating on different initiation conditions. In this paper, the numerical methods for the LS equation of three-dimensional detonation wave are introduced. Detail are introduced as following: transfering the LS equation to difference equation, setting the initial conditions for different shape explosive at different initiation way (point, line, plane, divergent or convergent); the dealing method of different edge conditions; how to draw the curve graph in two dimensional space or surface graph in three dimensional space with the calculated data. Two kinds of initiation way are designed in this paper. By means of high-speed frame camera, streak camera and SVR electrical camera, the propagation process and the interaction of the detonation wave are recorded for several kinds of explosive (DGO IA, B and JB90 14) at different imitation way. Finally, based on the basic theory model of LS method applied to three dimensional detonation wave propagation, we compile the calculation code LS3D. By employing the code LS3D, the propagation processes of ideal detonation wave at different shape explosives initiated by different way (point, line, plane) are calculated. The detonation propagation problems of insensitive high explosive JB9014 with different shape (cylinder, arc, pie) initiated from one plane are numerical simulated. The calculated results agree with the experimental results at some degree. In addition, the problems of convergent detonation and detonation wave propagating in planewave lens with multi-medium and the interaction of detonation waves are calculated. All the calculated results show that: the code LS3D can be used for calculating the detonation wave propagation in different explosive initiated by different way. It can deal with different shape, multi-medium explosive. The veracity of calculated results is depended on the relation of detonation speed with the curvature of detonation front and the edge angle of explosive with air or other medium. Measurement for these key parameters is an important study aspect of detonation wave propagation. It is very difficult and not veracious to simulate the three dimensional detonation wave propagation by means of fluid mechanics code. But the Level Set method is a practicable technology. In this paper, some primary methods of resolution for some key problems of LS method are given, and some propose are given for improving this method.