Simulation And Experimental Study On The Explosion Shock Wave Of Thermobaric Explosives In Different Environments

This thesis mainly studies the explosion properties of thennobaric explosives with different formulations by the ways of theoretical analysis,numerical simulation and detonation tests both in confined space and in open space.Through the theoretical study,the thesis analyses the interaction mechanism of thermobaric explosives and the propagation of the shock wave in open space.It elaborates the interaction mechanism of thermobaric explosives in the confined space and the empirical formulas for evaluating the quasi-static pressure with the help of the numerical simulation software AUTODYN.Through the analysis of numerical simulation of the thermobaric explosives with different parameters in open space,the proportion and the density of central booster explosives,the density of main explosive to make a more complete detonation of thermobaric explosives can be determined.The charge parameters have some effect on the over-pressure of shock wave of the thermobaric explosives at the near-field,while there have little effect on shock wave at the mid and far field.When the proportion of central booster explosive comes up to 8%,the density of central booster explosive is 1.753 and the density of main explosive is 1.95,the over-pressure of shockwave of the thermobaric explosive at the near-field reaches is highest.To assess the influence of shells constraint strength on detonation performance of explosives,some thermobaric explosive in different constraint strength are tested in static blast experiment in air.The explosion process was simulated with AUTODYN software.The results show that the initial shock wave parameters,the after-burning pressure and the shock wave decay rate of explosives without shell is higher than that of the explosives with shells in the same charging volume condition,and the initial shock wave parameters,the after-burning pressure and the shock wave decay rate of explosives in aluminum shells is higher than that in steel shells.The errors of peak pressure and action time between experiment and simulation are so small that it can be neglected.The arrival time of after-burning pressure of explosives without shell is earlier than that of the explosives with shells,and the arrival time of after-burning pressure of explosives in aluminum shells is earlier than that in steel shells.The thickness of the shell have a larger impact on initial shock wave overpressure and the metal shells delay the spread of shock wave.To assess the influence of the Al/O mole ratio on explosion performance of thermobaric explosives in closed atmosphere,different kinds of thermobaric explosive are taken into account,and their Al/O mole ratio are different.The overpressure,the impulse and the quasi-static pressure of the shock wave were obtained in the closed explosion chamber.The explosion process was simulated with AUTODYN software.The results show that the overpressure,the impulse and the quasi-static pressure of the shock wave reach the maximum value when the Al/O mole ratio of the thermobaric explosives from 0.5 to 0.8.The energy output effects can be better.The errors of overpressure,impulse and the quasi-static pressure of the shock wave between experiment and simulation are so small that it can be neglected.The Miller reminder can describe the after burning features of thermobaric explosive reasonably.