Research On Multipoint Ignition By Microwave

With the development of modern military science technology and the cross-fertilization of multidisciplinary technology,the military weapons technology of various countries ushered in a new round of breakthroughs,and traditional ground suppression weapons artillery is also constantly innovating,microwave ignition as a new type of artillery ignition technology has attracted much attention.Microwave ignition technology has many advantages due to its short ignition delay,good uniformity,simple structure,better compensation for combustion,etc.It has wide application prospects in the field of ignition and heating technology,such as:microwave ignition of various engines,microwave ignition of artillery,microwave plasma moment,metallurgy,microwave treatment of biological environment,and other fields.Based on this,this thesis starts from the basic theory,around the microwave and plasma for simulation analysis and experimental investigation,combining theory and experiment to carry out the research of microwave multi-point ignition of artillery.In this thesis,we analyzed the mechanism of microwave ignition of gunpowder,designed a microwave multi-point ignition device based on coaxial resonant cavity,completed sample processing,built and tested the relevant experimental platform,completed microwave ignition experiments,and explored the practicality of microwave ignition technology in the field of artillery.The main research work and conclusions of this thesis are as follows:（1）Combining the theoretical basis of microwave heating,microwave plasma breakdown and microwave transmission in plasma,it is determined that the key to breakdown ignition lies in reaching the breakdown electric field threshold,and through breakdown process analysis and formula derivation,the breakdown electric field threshold calculation formula is given,and a simplified model curve for pyrotechnic microwave ignition is proposed to provide theoretical guidance for subsequent simulation analysis and experiments.（2）Design a reasonable coupling transition section and ignition coaxial resonant cavity structure,according to the structural characteristics of ordinary coaxial resonant cavity calculated from its theoretical breakdown electric field strength threshold of about1.5×10~6（1/8）.At the same time,further design optimization of low-power ignition resonant cavity,by adding the method of ring piece to increase the local field strength,and then reduce the power required for breakdown,the simulation results show that the electric field strength is locally enhanced by one order of magnitude.The threshold of breakdown electric field strength obtained from the low-power resonant ignition cavity is calculated to be about 1.67×10~6（1/8）,and the electric field near the ring piece can reach the breakdown threshold at 4k W input power.The two structures designed above are then subjected to microwave plasma simulation in multi-physics field simulation software,which in turn verifies the correctness of the theoretical model and structural design,and concludes that the ignition delay of the low-power resonant cavity is shorter by observing the electric field strength and electron density variation at 4k W input power.（3）complete the testing and construction of the experimental platform,according to the simulation model structure of the resonant cavity processing,while fine-tuning the parameters of the resonant cavity to achieve a more accurate resonant frequency point,based on the construction of the microwave ignition experimental platform for charging experiments,through the experimental phenomenon and data to determine the basic requirements of microwave ignition.This thesis on microwave multipoint ignition provides an important theoretical and experimental research basis for the application of microwave ignition technology in artillery ignition.