Study Of The Automatic Cover Opening By Jet Flow Based On Dynamic Mesh Technology

The technique of using fragile meterial as the pre-and-post cover and then the opening of covers depending on the shock wave with gas jet has been widely used in the missile launching tank.When the pre-cover opening depends on the shock wave,the opening-type and the opening-pressure of post-cover play the esstional roles for the opening of pre-cover.Similarly,when the opening of post-cover depends on the shock wave with gas jet,the opening-type and the opening-pressure of the nozzle cover play the esstional roles for the opening of post-cover.In order to study the effect that the different opening-types and the different opening-pressure of the nozzle cover on initial shock wave and post-cover,this paper simulates the opening process of the nozzle cover by coupling the motion process of the nozzle cover with gas jet flow field based on laying,smoothing and remeshing dynamic method.Arrording to the results of the calculation it can be seen clearly that the nozzle cover is opened in different ways,resulting in different effects of gas jet on post-cover.In addition,when the nozzle cover is opened by different pressure,the intensity of initial shock wave is also different.And the changing curves of the pressure on the post-cover with time are obtained from the analysis results.The research results show that compared with the whole open nozzle cover,the opening-pressure of post-cover is reached earlier by using pyrolytic carbonization nozzle cover.Also, with initial shock wave intensity,the spread velocity and the duration are all augmented as the nozzle cover opening-pressure increased.In order to study the effect that the different opening-types and the different opening-pressure of the post-cover on pre-cover,this paper simulates the opening process of the post-cover by coupling the motion process of the post-cover with gas jet flow field based on smoothing and remeshing dynamic method.Arrording to the results of the calculation it can be seen clearly that the post-cover is opened in different ways or by different opening-pressure,the intensity of shock wave in the tank is also defferent.And the changing curves of the pressure on the monitoring points,the average pressure of the pre-cover with time are obtained from the analysis results.The research results show that compared with uncoupled post-cover opening,by using coupled post-cover opening,the shock wave in tank intensity bigger,duration longer.Also,with the shock wave intensity,the spread velocity and the duration are all augmented as the post-cover opening-pressure increased.It also means the opening pressure of pre-cover is reached earlier as the post-cover opening-pressure increased.