Analysis of Ablation Mechanism of Iron Asteroid Materials Under the Condition of Arc Heater Test

Abstract

When the asteroid enters earth’s atmosphere at a very high speed，the surface temperature rises and the surface material melts and loses under the severe aerodynamic heat. Studying the ablation mechanism of iron asteroids entering the Earth’s atmosphere is of great significance to study the ablation mechanism of iron asteroids entering the Earth’s atmosphere to evaluate the impact of such asteroids on the earth. In 2021，the Hypervelocity Aerodynamics Institute of China Aerodynamics Research and Development Center carried out the ablation test of the spherical cone-shaped iron meteorite model（head radius 20 mm，half cone angle 9 degrees）on the arc heater. The tested simulated state is that the stagnation heat flux is 13.9~19.5 MW/m² and the stagnation pressure is 0.51~0.28 MPa. In this paper，based on the experimental phenomenon，the melting ablation model and the melting layer shear ablation model of iron asteroid material ablation are established. and the ablation test state of meteorite model is calculated by using the coupled solution methodology of aerodynamic heat，ablation and internal heat conduction with moving boundary. The calculation and analysis show that the shear ablation model established in this paper can obtain qualitatively consistent stagnation point ablation rate. If the loss of liquid layer is not considered，the calculated law is contrary to the experiment. The calculation shows that the surface evaporation rate is small compared with the mass loss rate of molten layer，which indicates that the ablation of iron asteroids is dominated by the shear loss of molten layer. It can provide reference for asteroid impact Earth defense.

Keywords

iron asteroid / ablation / melting / shear loss

References

[1] CHYBA C F,THOMAS P J,ZAHNLE K J. The 1908 tunguska explosion:atmospheric disruption of a stony asteroid[J]. Nature,1993361:40-44.
[2] POPOVA O P,JENNISKENS P,EMEL'YANENKO V,et al. Chelyabinsk airburst,damage assessment,meteorite recovery and characterization[J]. Science,2013,342(6162):1069-1073.
[3] SCHULTE P,ALEGRET L,ARENILLAS I,et al. The chicxulub asteroid impact and mass extinction at the cretaceous-paleogene boundary[J]. Science,2010,327:1214-1218.
[4] 柳森,党雷宁,赵君尧,等. 小行星撞击地球的超高速问题[J]. 力学学报,2018,50(6):1311-1327.LIU S,DANG L N,ZHAO J Y,et al. Hypervelocity issues of earth impact by asteroids[J]. Chinese Journal of Theoretical and Applied Mechanics,2018,50(6):1311-1327.
[5] 党雷宁,柳森,白智勇,等. 小行星进入与撞击效应评估模型敏感性研究[J]. 力学学报,2021,53(1):278-292.DANG L N,LIU S,BAI Z Y,et al. Sensitivity research on models of earth entry and impact effects by asteroids[J]. Chinese Journal of Theoretical and Applied Mechanics,2021,53(1):278-292.
[6] MASON B H. Meteorites[J]. American Scientist,1967,55(4):429-455.
[7] ČEPLECHA Z,BOROVIČKA J,ELFORD GW,et al. Meteor phenomena and bodies[J]. Space Science Reviews,1998,84:327-471.
[8] 李世杰. 小行星的分类及飞行器探测历史[J]. 大众科学,2021,(1):56-59.
[9] AGRAWAL P,JENNISKENS P. Arcjet ablation of stony and iron meteorites[C]//Proceedings of 2018 Aerodynamic Measurement Technology and Ground Testing Conference. Georgia,USA:[s. n.],2018.
[10] 王磊,罗跃,党雷宁,等. 模拟陨石进入的电弧风洞烧蚀试验及辐射特性分析[C]//第四届全国行星防御研讨会论文集. 桂林:第四届全国行星防御研讨会,2021.
[11] GIRIN O G. A hydrodynamic mechanism of meteor ablation:the melt-spraying mode[J]. Astronomy Astrophysics,2017,606:A63.
[12] ČAPEK D,BOROVIČKA J. Ablation of small iron meteoroids-frist results[J]. Planetary and Space Scicnce,2017,143:159-163.
[13] ČAPEK D,KOTEN P,BOROVIČKA J,et al. Small iron meteoroids-Observation and modeling of meteor light curves[J]. Astronomy & Astrophysics,2019,625:A106.
[14] 罗跃,王磊,党雷宁,等. 模拟Chelyabinsk小行星进入的烧蚀实验[J]. 力学学报,2020,52(5):1362-1370.LUO Y,WANG L,DANG L N,et al. Arcjet ablation experiment to simulate the chelyabinsk asteroid entry[J]. Chinese Journal of Theoretical and Applied Mechanics,2020,52(5):1362-1370.
[15] FAY J A,RIDDELL F R. Theory of stagnation point heat transfer in dissociated air[J]. Journal of Aerosol Science,1958,25(2):73-85.
[16] ZOBY E V,MOSS J N. SUTTON K. Approximate convective heating equations for hypersonic flows[J]. Journal of Service Research,1981,18:64-70.
[17] 张志成,潘梅林,刘初平,等. 高超声速气动热和热防护[M]. 北京:国防工业出版社,2003:222-284.
[18] 吴斌,夏伟,汤勇,等. 身管熔化烧蚀的预测数学模型[J]. 火炮发射与控制学报,2002,24(1):5-10.WU B,XIA W,TANG Y,et al. Mathematical model for predicting melt-erosion in gun barrels[J]. Journal of Gun Launch & Control,2002,24(1):5-10.
[19] OSTROWSKI D,BRYSON K. The physical properties of meteorites[J]. Planetary and Space Science,2019,165:148-178.