Interior Ballistic Study And Launch Dynamic Analysis About Rarefaction Wave Propulsion Technology

The research is developed and aims at the new high performance weapon system------Rarefaction Wave Gun(RAVEN). The propulsion mechanism of RAVEN, the structure design and working performance of blow back device, the numerical simulation of interior ballistic process, the research and optimization of propulsion performance, the vibration response and dynamic characteristics of gun are studied in this dissertation. The main parts are concluded as follows:(1) The structure and working performance of the key part of RAVEN------blow backdevice is studied. The selection rule of blow back device and feasible venting method are given based on the propulsion mechanism and the realization processes of RAVEN. Combined with the working principle of the inertial breech blow back device, the structure parameters are made, and then the calculation method about the venting time is obtained by the rarefaction wave propagation theory as well. The calculation model of the venting flow field is established, the venting flow and aftereffect range of the propellant gas under the different structure of the blow back device are analyzed, and then the working performance of different blow back devices are verified.(2) One-dimensional two-phase flow interior ballistics mathematical model of the RAVEN is established and its numerical simulations are conducted. The change laws of interior ballistic parameters are analyzed. The special firing phenomenon is given by comparing calculation with the conventional close-breech gun. The rules of how the surface relative burning-rate coefficient, relative thickness of the deterred layer and main structure characteristic parameter of deterred propellant grain effect on the interior ballistic performance are made by calculation. Meanwhile the dual one-dimensional two-phase flow interior ballistics mathematical model of the Front Orifice Rarefaction Wave Gun is established and its numerical simulations are conducted. The change laws of interior ballistic parameters in the bore and airway are obtained and the effect on the interior ballistic performance of structure parameters of the airway and deterred propellant performance is analyzed.(3) The analysis and optimization design about the propulsion performance of the Rarefaction Wave Gun is developed for its unique performance advantages. The calculation formulas about recoil force, recoil impulse, barrel heat and energy conversion in the propulsion of Rarefaction Wave Gun and the conventional close-breech gun are established. By the numerical calculation, the performances of the Rarefaction Wave Gun in the reducing the recoil and barrel heat and increasing practical efficiency of propellant are verified. The rules how the different loading conditions including the loading charge mass, chamber volume, projectile mass and engraving pressure, the venting time and the structure parameters of blow back device affect on the performance are obtained. On this basis, the multi-object optimization model of the propulsion performance of the Rarefaction Wave Gun is established and the corresponding solving method is given by combining the corresponding evaluation standards of the propulsion performance. Make the loading density and the venting time as the main optimization variables, the feasible project are made out to satisfy different evaluation criterion by the calculation.(4) The dynamic vibration equation of the Rarefaction Wave Gun is established and its numerical simulations are conducted. The vibration responses in the action of the propellant gas, projectile and the inertial breech are obtained. The rules of how the different parameters including the loading density, projectile mass, barrel length, venting time , inertial breech mass and the expansion ratio of nozzle section effect on the vibration response is given. Comparing calculation with the vibration response of the conventional closed-breech gun, the specific vibration phenomenon is also obtained. The modeling method about the dynamic problem of the rigid-flexible coupling system is given, and then the rigid-flexible coupling dynamic model that describes the whole dynamic response of the Rarefaction Wave Gun system is established and its numerical simulations are conducted. The dynamic characteristics of the coupling effect between body system and gun barrel is given.