Research On Microwave Ignition Technology Based On Coaxial Resonator

As a new type of ignition technology,microwave ignition technology has many advantages: the ignition response speed is fast,and instant ignition can be achieved;it has the outstanding advantages of uniformity and simultaneity of ignition;the ignition device has a simple structure without electrodes,which overcomes the problem of accidental ignition.Dangerous,with high safety and reliability.Therefore,the application of microwave ignition technology in the gunpowder ignition system is of great significance to further improve the ignition performance and promote the development of aerospace and military weapons.Based on this,the research of microwave ignition in the field of gunpowder ignition is carried out in this thesis.Mainly completed the following work:（1）Three microwave ignition cavities are designed based on the principle of coaxial resonator,namely no probe structure,single probe structure and multi-probe structure,which can realize gunpowder ignition from bottom ignition to internal ignition,and from single point ignition.to the need for multiple ignitions.The height of the three ignition chambers is less than 33 mm and the diameter is less than 17 mm,which lays the foundation for the miniaturization and lightweight research of microwave ignition technology in the field of gunpowder ignition.Machining and performance testing experiments are carried out on the determined cavity size scheme.The experimental results show that when the resonant frequency of the three cavities is 2.45 GHz,the cavity S11 is less than-12 d B,the microwave feed is good,and the performance meets the design requirements.（2）The electromagnetic-thermal multi-physics coupling simulation study was carried out for three microwave ignition cavity models,and the powder ignition time of the three cavity models under different microwave input powers was predicted.On the platform,the gunpowder ignition test experiment was carried out on the three cavities at different microwave input powers of 20W-100 W,and the three cavities can achieve rapid ignition.The feasibility of the microwave ignition scheme is verified by simulation and experiment.In addition,the effect of carbon nanotubes on microwave ignition efficiency was investigated experimentally,and the ignition speed of gunpowder doped with carbon nanotubes would be doubled.（3）According to the actual demand,a set of automatic test system for dielectric constant temperature change using negative pressure and microwave heating is built.The system uses microwave heating to replace the traditional resistance wire heating.negative pressure environment.The system realizes the automatic reading and calculation of data by the vector network analyzer during the experiment through Labview programming,uses the controller to control the displacement stage to transport the sample to the designated position,and finally adjusts the operation cycle of each device to realize the automatic test of the variable temperature test system.The dielectric constants of a certain porous dielectric material and gunpowder with temperature were obtained through experiments,which made necessary preparations for the follow-up work.