Calculation And Analysis Of Interior Ballistics Of Automatic Compensator In Launch

The missile launch method of eject utilizes the additional energy to provide the thrust for the missile,and it does not need to consume the energy of the missile.It has the advantages of large acceleration,fast speed and far firing range.As a kind of eject emission method,gas ejection has the characteristics of small volume and high energy.The shortcoming is that the gas temperature is high and the pressure is big and uncontrollable.Therefore,it is of practical significance to study and optimize the process of gas ejection process.In this paper,the CFD numerical calculation has been used as the main means of research to study the gas ejection internal ballistic flow field.The main work includes the following aspects:Firstly,the original gas ejection tube model is established,and the moving process of the missile is simulated by moving grid method.The kinematic parameters such as thrust,velocity and displacement of the missile are obtained through the simulation.According to the ballistic flow field in different period,the whole process is divided into two phases: the initial oscillation phase and the steady diffusion phase.The main factors that influence the internal pressure of the low pressure chamber and the flow field characteristics of each stage are analyzed.According to the different dimension of the expansion space and the size of the through-hole,four conditions were designed,and the motion parameters such as thrust,speed and displacement of the missile were obtained by simulation analysis.The characteristics of the flow field of the self-compensating gas ejection ballistic are analyzed,and the main factors that influence the pressure change in the initial oscillation phase and the steady diffusion phase are analyzed.Compared with the simulation results,the following conclusions are obtained: the size of the through-hole has little effect on the internal-ballistic parameters of the selfcompensating gas ejection;the increase of the initial expansion space can effectively reduce the increase of the thrust force value and the thrust peak.In a certain range,the larger the initial expansion space volume,the slower the thrust value increases and the lower the peak value.