Research On The Muzzle Flow Field With The Fin-Stabilized Opening Device Through The Three-Dimensional Numerical Simulation

In order to research the character of muzzle flow field with the fin-stabilized device and the stress state of the fin-stabilized device out of muzzle and during the fins' unfolding,the thesis based on the weaponry platform of 100 mm smooth-bore gun,the computational fluid mechanics was utilized,on the combination with the three-dimensional N-S equation of the compressible unsteady airflow,the hydrodynamic analysis software was applied,the flow field both without and with the fin-stabilized device was analysed with three-dimensional numerical simulation by dynamic grid method respectively.The main contents included:(1)The control equation and turbulence model was selected on the basis of characteristics with propellant gas flow field,the computational model of muzzle flow field of fin-stabilized sevice and without fin-stabilized device was established respectively;(2)The interior ballistic equation was established,the internal ballistic parameters on the process of projectile motion in bore was calculated,the initialization condition of muzzle flow field numerical simulation was determined;(3)The grid of the muzzle flow field both without and with fin-stabilized device was divided by the dynamic division story method and the local reconstruction method of moving-grid technology respectively,the boundary conditions ?materials physical properties of muzzle flow field numerical simulation was determined,the results was calculated by the three-dimensional numerical simulation with FLUENT software;(4)The pressure?velocity?temperature and other parameters distribution of muzzle flow field airflow cloud picture and contour map was obtained in the two different conditions,the formation and development process of the muzzle flow field after the projectile from the muzzle and the stress state of fin-stabilized device in the muzzle brake was described;(5)The whole process of wing opened was simulated,the pressure cloud picture and single vane-the powder gases force on its axis of rotation torque on the process of wing opened at different times was obtained,the force condition of the tail wing,the distribution characteristics of the muzzle flow field in the whole process was analyzed.The results showed that: dynamic grid technology can simulate the characteristic of muzzle flow field with fin-stabilized device successfully;the local reconstruction method can deal with a combination of translational and rotational motion such as projectile motion and fins' unfolding satisfactorily;numerical simulation results is useful for the research of muzzle flow field characteristics,the distribution of empennage,the tail of opening movement and the design of fin-stabilized device.