Numerical Simulation Of Laser Thermal Ablation Effect In Atmosphere And Study Of Damage Effect Assessment Method

In recent years,high-energy laser weapons have attracted much attention and developed rapidly because of their rapid response,accurate attack and high efficiency-cost ratio.The damage mechanism of high-energy laser weapon is that the high-energy laser beam acts directly on the target and reacts with the target material in a complex physical and chemical way,which changes the structure and function of the target and produces a very effective destructive force.The damage effect evaluation of high-energy laser weapons mainly involves the atmospheric transmission characteristics of high-energy laser,laser-material interaction,target damage effect evaluation and so on.At present,the related research is in the stage of modularization.In the study of the interaction between laser and matter,the thermal ablation effect of ideal Gauss beam is still the main one,and the distortion of facula caused by thermal halo and turbulence effect of high-energy laser propagating in the atmosphere has not been considered.There are few reports on the evaluation method of damage effect of laser weapon.It is of great significance to combine the modules and finally give the damage effect evaluation method of laser weapons.The numerical simulation of laser thermal ablation effect in the atmosphere can not only quantitatively analyze the ablation effect of targets in the actual atmosphere,but also provide the main basis for the research of damage effect evaluation methods of laser weapons.In this paper,the high-energy laser atmospheric transmission characteristics module and the laser-matter interaction module are effectively combined,and the relevant numerical simulation program is compiled.Firstly,based on the theory of thermal blooming and turbulence effect of high-energy laser propagation in the atmosphere,the atmospheric propagation characteristics of high-energy laser are simulated numerically.From this,the distribution of high-energy laser reaching target in the atmosphere is obtained.Then,the thermal ablation effect of laser on metal materials is simulated numerically by finite element method.Through the numerical simulation program and its processing flow,the thermal ablation effect of high-energy laser beam propagating in the atmosphere can be calculated directly.A three-dimensional target model is established to simulate the thermal ablation effect of ideal Gauss beam,thermal halo effect and turbulence effect on the aluminum target.The temperature distribution and heating process of the aluminum target under different laser and atmospheric parameters are analyzed,and the rules of penetration and ablation of the aluminum target under corresponding conditions are discussed.At the same time,under given laser parameters and atmospheric parameters,the thermal ablation differences of targets with different materials,thickness and shape were compared.The results have important reference value for the study of the interaction between high power laser and matter in the atmosphere.On this basis,considering that the damage effect evaluation of laser weapons has not yet a more general method and process,aiming at the characteristics and requirements of laser weapons,the Vulnerability and Lethality analysis method based on model calculation is selected,and the complete process of damage effect evaluation of laser on typical targets is preliminarily given.Taking a typical missile target attacked by laser as an example,the vulnerability of the target is analyzed.After determining the key components,the damage criterion is subdivided according to the characteristics of each component,and the conditional damage probability corresponding to the physical damage information of each component is expressed in a piecewise form.In the scenario of battle,the evaluation process is further illustrated and verified by a specific example.