Study On The Interior Ballistic Design Method Of Modular Charge Based On Discrete Element Method

The study takes modular charge of large-caliber gun as background.The method of modular charge interior ballistic calculation is researched based on discrete element method(DEM),it provides a new way and method for interior ballistic design.The main research contents and results are as follows:1.Study on the establishment method of propellant discrete element modelFirst,the study takes seven-hole cylindrical propellant and nineteen-hole lacy propellant as modeling objects,their shape features are analyzed and a 3D modeling method of porous granular propellant in SolidWorks is proposed.Then,the 3D model of propellant is used as particle template in EDEM,the discrete element model of propellant is established by filling in the template.Finally,in order to improve the efficiency of modeling,SolidWorks is redeveloped with C#,connecting the shape parameter database through the design interface,shape parameter driven 3D modeling of propellant structure is realized.2.Study on the determination of friction coefficient between propellant particlesFirst,the static friction coefficient between propellant particles coated with graphite is measured using self-regulating cant instrument.Then,the rolling friction coefficient(rfc)is measured.A propellant particle deposition experiment is designed.Next,simulating the experiment process in EDEM,the linear fitting equation of simulation repose angle with rfc is got.After that,using the method of parameter calibration based on the test repose angle to get the parameter value.Finally,the effect of friction coefficient on loading density is investigated and the results show that when the friction coefficient is increased,the charge of module will decrease accordingly,vice versa,therefore,the influence of friction coefficient on loading density is not negligible.3.The interior ballistic calculation method of module chargeFirst,the interior ballistic model of module charge is established.Next,discrete element model of gun propellant and geometric model of module are established,and the process of module loading the propellant is simulated by discrete element simulation,the number of particles and the void fraction of propellant in the module are obtained,and the results show that if the shape parameter is different,the charge of module is different.Then,other calculation parameters of interior ballistic are introduced,the charge and the charge density are calculated according to discrete element simulation result.Finally,the interior ballistic of module charge is calculated.