Calculation Of The Distribution Of Explosive Energy In Air

The key to improve blasting quality and use blast energy reasonably and effectively is to control the distribution of blast energy.Therefore,full and reasonable use of explosive energy has always been a concern for blasting workers,and it is also an eternal topic in the study of explosion theory and application.However,because of the variety of rocks,the constitutive relationship is very complicated,so the research on its energy distribution is very difficult.In this paper,a relatively simple calculation of the near-field energy field in air is carried out on a large scale based on a three-dimensional multi-material plastic-elastic hydrokinetics MMIC-3D(Multi-Material in Cell for 3D)hydrocode of EULER finite difference method.Throughout the calculation domain,the energy integrals of each space-time grid node are summed up to track the entire dynamic process of energy release,transformation and dissipation during air explosion and to quantify various energy of accounts for a share of the total energy.The main contents of the thesis are described as follows:1.Through the investigation of the theory of the air explosion at home and abroad,numerical simulation method has been chosen to research blasting in air.Research Ideas and methods of this paper were established.2.The basic equations of the fluid dynamics used in the three-dimensional Euler-type explosion program were described.The state equations of different media in the program were described.Numerical methods used in the three-dimensional explosion program were summarized.Transport scheme and multi-material interface of fuzzy interface theory were expounded.3.Numerical simulations of the explosion in the air and the explosion in the infinite wall were carried out.The law of the expansion of the explosive charge in the air and the propagation of the shock wave in the presence of the retaining wall were analyzed.Comparing the overpressure of shock wave and the overpressure calculated by the empirical formula obtained from the explosion simulation in the infinite air,the two results are similar.At the same time,it is found that increasing the amount of cell(fining the cell)can make the compute result more accurate.4.The energy of the air and detonation products in the calculation domain is calculated according to the internal energy,kinetic energy,and pressure potential energy,and the different energy of each medium is analyzed separately,and the energy conservation relationship is calculated.The reasons for the non-conservation of the energy in the calculation results are analyzed.It is found that the size of the grid has a great influence on the accuracy of the calculation results,and the non-conservative form of the difference scheme used in the program also brings a calculation error to the energy conservation...