Research On The Launching Technology Of Large-caliber Expansion Wave Gun Based On Interior Ballistic Simulatio

With the gradual improvement of the performance requirements of weapon systems in modern battlefields,compared with conventional artillery,the rarefaction wave gun developed based on the new launching mechanism not only ensures the muzzle power,but also realizes the launching process of low recoil and low barrel heat,which significantly improves the performance of the artillery.The rarefaction wave gun will also open a new era of light artillery.From a technical point of view,How to reduce the reaction force generated by the back blow as much as possible is the key to the further development of the rarefaction wave gun without affecting the muzzle velocity of the projectile.In addition,in order to solve the practical engineering application problems,it is necessary to determine the dangerous range of the venting flow field shock wave and carry out the design research of the exhaust back blow mode of the rarefaction wave gun.In this paper,the large rarefaction wave gun is taken as the research object,and the above problems are analyzed and simulated accordingly.The main research contents are as follows:(1)Using the interior ballistic data of the same type of conventional artillery,the law of the expansion wave propagation in the bore is obtained by fitting and solving with the back-stepping method,and the venting time of large rarefaction wave gun is calculated.At the same time,aiming at the launching process of large rarefaction wave gun,a one-dimensional homogeneous flow interior ballistic model is established,and the model is solved by CTVD of two-step component type of second order accuracydifference scheme.By understanding the variation law of various parameters in the bore of large rarefaction wave gun,and comparing with the recoil impulse of conventional gun,the recoil reduction efficiency of large rarefaction wave gun is obtained.(2)Three-dimensional compressible N-S equation is used to describe the gas flow of rear-jet shock wave of large rarefaction wave gun.Combined with the calculation results of interior ballistics,the numerical simulation of the free-jet shock wave flow field of rear-jet and the interaction between rear-jet shock wave flow field and ground is carried out,and the occurrence and development law of rear-jet shock wave of large rarefaction wave gun is studied.Use numerical results to determine the magnitude and safety range of post-injection shock wave pressure.(3)A lateral double exhaust structure is designed to control the opening and closing of the exhaust hole of the chamber by the movement of the piston rod,and its aerodynamic analysis is carried out to determine the thermal change process in the chamber,and the movement speed displacement of the piston of the device is studied on the basis of the pressure change law of the chamber.In addition,the thrust of the nozzle of the device is estimated,Ensure the rationality of the device.