Research On The Design Of Mine Insensitive Fuze Pressure Relief Structure

This paper aims to provide a theoretical reference for the development and application of mine insensitive fuze technology and insensitive ammunition in China,and to design and study the pressure relief hole of mine concentrated energy burst tube with the thermal safety of mine insensitive fuze concentrated energy blaster tube as the engineering background.Firstly,the research status of roasting combustion and the design of pressure relief holes at home and abroad are introduced.Through the analysis,comparison and combination of the research object,for the mine fuse shaped energy squirt tube charged with JH14 explosive,the minimum pressure relief hole area of the shaped energy boomer with the charge of JH14 is calculated after ignition based on the pressure equilibrium of the explosive at the moment of ignition,and then different sizes,different positions and different numbers of pressure relief holes are designed.Using the method of combining numerical simulation and experiment,the response characteristics of concentrated energy blast pipes with different sizes of pressure relief structures in slow and fast cook-off environments are analyzed,and the thermal reaction equation and heating rate model of explosives are described by writing user-defined functions,and on the basis of establishing a three-dimensional axisymmetric cookover calculation model,Fluent is used to numerically simulate the slow and rapid cook-off response characteristics of different sizes,different positions and different numbers of pressure relief holes.The effects of different slow roasting heating rates and different fast roasting temperature rise models on the slow roasting response characteristics and fast cook-off response characteristics of the concentrated energy boom tube were analyzed.Based on numerical simulation,the initiation verification test of the pressure relief pore concentrated energy boom tube was carried out,and the effectiveness of the shaped energy burst tube with different sizes of pressure relief structure and the reliability of the pressure relief hole concentrated energy burst tube that can ignite the main charge were tested and verified,and the witness version was used to compare whether the pressure relief pore concentrated energy explosion tube was perforated during the explosion.The simulation results show that under the condition of slow cooking,the response time of the shaped burst pipe is significantly extended with the increase of the size of the pressure relief hole.The effect in the upper position of the sidewall is obviously better than that of the middle position and the lower position of the sidewall,because the ignition point of the shaped energy boom pipe is located on both sides of the upper end of the solid column when the explosive is slowly roasted,and the pressure relief hole can release the pressure in time when the upper part of the sidewall;When the area of the pressure relief hole is the same and the number increases,its response time is prolonged,which is because the heating rate on both sides of the wall can be consistent when the explosive is burned,the temperature is heated uniformly,and the pressure relief holes on both sides can timely discharge the gas generated by the self-reaction of the explosive,thereby prolonging the response time of the ammunition;With the increase of heating rate,the response time of the shaped burst tube is significantly shortened,and the heating rate has little effect on the ignition temperature.Under the rapid cook-off condition,different flame temperature rise models have a greater influence on the cook-off response time of the fuse,the higher the flame temperature,the shorter the response time,and the ignition position is always located at the bottom of the shaped blast tube.The test results show that the initiating power of the shaped energy boom pipe decreases with the increase of the pressure relief hole,and the designed pressure relief hole can meet the conditions of igniting the main charge in the test.Based on the simulation,test results and influencing factors,the pressure relief hole design of this type of shaped energy boom pipe is 7mm with a single hole diameter of 7mm,and the position is located in the middle of the sidewall of the shaped energy boom pipe,and the research results have certain guiding significance for the thermal safety and pressure relief structure design of mine-insensitive fuses.