In view of the unique CO2 rarefied gas environment of Mars and the high-temperature real gas effect during the high supersonic velocity entry of the rover into Mars,the excitation characteristics of CO2 multi-vibrational modes was studied. Unstructured grid and direct simulation Monte Carlo method(DSMC)and the non-resonant oscillator vibration excitation model was adopted in this paper. The dissociation energy of CO2was evenly divided into four vibration modes,and then the highest vibration energy level of each mode was limited,and a high temperature rarefied real gas chemical reaction model with 5 components 17 reaction containing CO2 was simulated. The high-temperature chemical non-equilibrium effect flow field of “Mars Pathfinder”was calculated at an altitude of 65 km with entry velocity of 7 453 m/s and angle of attack of 0° in the Martian atmosphere. The results show that the CO2 is decomposed dramaticlly after the excitation and consumes a large amount of energy. The percentage of components in the windward excitation and the properties of the probe surface are consistent with the literature results,which proves the feasibility of this paper for the CO2 vibration excitation treatment method. On this basis,the N2 component was added to simulate the flow field of the 8 component,44 reaction of the Martian atmosphere,and the change of flow field characteristics was analyzed by changing the incoming flow density and Mach number. The results show that the flow field temperature increases and then decreases as the incoming flow density decreases,and the surface heat flow density increases. With the increasement of incoming Mach number,the flow field temperature and pressure increases,and the surface heat flow density increases. However,the Mach number shows little effect on the coetlicient of heat flow density.
Key words
hypersonic /
CO2 /
vibration excitation /
chemical reaction /
direct simulation Monte Carlo(DSMC)method
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References
[1] 欧阳自远,肖福根. 火星探测的主要科学问题[J]. 航天器环境工程,2011.
OUYANG Ziyuan,XIAO Fugen. The main scientific issues of Mars exploration[J]Spacecraft Environmental Engineering,2011,28(3):205-217.(in Chinese)
[2]BRAUN R D,MANNING R M. Mars exploration entry,descent and landing challenges[J]. Journal of Spacecraft and Rockets,2007,44(2):310-310.
[3]杨肖峰. 火星探测器气动力热和传热特性研究[D]. 绵阳:中国空气动力研究与发展中心,2013.
YANG Xiaofeng. Research on the aerodynamic,thermal,and heat transfer characteristics of Mars explorers[D]. Mianyang:China Aerodynamics Research and Development Center,2013.(in Chinese)
[4]黄纯珺. 探路者号的进入、降落、着陆[J]. 中国科技信息,1997,18:26-27.
HUANG Chunjun. The entry,landing,and landing of the Pathfinder[J]. China Science and Technology Information,1997,18:26-27.(in Chinese)
[5]吕俊明,程晓丽,王强. 火星科学实验室气动特性数值分析[J]. 力学与实践,2013,35(1):31-35.
LV Junming,CHENG Xiaoli,WANG Qiang. Numerical analysis of aerodynamic characteristics of Mars Science Laboratory[J]. Mechanics and Practice,2013,35(1):31-35.(in Chinese)
[6]TAEHYOUN,KIM,SATYA,et al. Monte Carlo simulation of entry in the Martian atmosphere[J]. Journal of Thermophysics and Heat Transfer,1993,7(2):228-228.
[7]BORGNAKKE C,LARSEN P S. Statistical collision model for Monte Carlo simulation of po-lyatomic gas mixture[J]. Journal of Computational Physics,1975,18(4):405-420.
[8]刘文剑,邓从豪. 双原子分子在改进的Morse势下的振动一转动问题[J]. 山东大学学报:自然科学版,1993,28(3):3209-3213.
LIU Wenjian,DENG Conghao. The vibration rotation problem of diatomic molecules under an improved Morse potential[J]. Journal of Shandong University:Natural Science Edition,1993,28(3):3209-3213..(in Chinese)
[9]HINDELANG F J. Coupled vibration and dissoction relaxation behind strong shock waves in carbon dioxide[R]. NASA Ames Research Centr Moffett Field,CA:HFJ,1967.
[10]MILLIKAN R C,WHITE D R. Systematics of vibrational relaxa-tion[J]. Journal of Chemical Physics,1963,39(12):3209-3213.
[11]CHUL PARK,ECER A,AKAY H U,et al. Assessment of a two-temperature kinetic model for dissociating and weakly ionizing nitrogen[J]. Journal of Thermophysics and Heat Transfer,1988,2(1):8-16.
[12]ROCK S G,CANDLER G V,HORNUNG H G. Analysis of thermochemical nonequilibrium models for carbon dioxide flows[J]. AIAA Journal,1993,31(12):2255-2262.
[13]PARK C,HOWE J T,JAFFE R L,et al. Review of chemical-kinetic problems of future NASA missions,II:Mars entries[J]. Thermophysics Heat Transfer,1993,8(1):1271-1273.
[14]BIRD G A. Molecular gas dynamics and the direct simulation of gas flow[M]. Oxford:Oxford Science Publications,1994.
[15]何涛. 火星大气稀薄流DSMC数值模拟技术研究[D]. 南京:南京航空航天大学,2016.
HE Tao. Research on DSMC numerical simulation technology for Martian atmospheric rarefaction flow[D]. Nanjing:Nanjing University of Aeronautics and Astronautics,2016.(in Chinese)
[16]杨超,孙泉华. 高温气体热化学反应的DSMC微观模型分析[J]. 力学学报,2018,50(4):722-733.
YANG Chao,SUN Quanhua. DSMC microscopic model analysis of high temperature gas thermochemical reactions[J]. Journal of Mechanics,2018,2018,50(4):722-733.(in Chinese)
[17]CARLSON A B,BIRD G A. Implementation of a vibrationally linked chemical reaction model for DSMC[R]. USA:NASA Langley Technical Report Server,1994.
[18]MOSS J N,WILMOTH R G,PRICE J M. DSMC simulations of blunt body flows for Mars entries:Mars Pathfinder and Mars microprobe capsules[R]. USA:NASA Langley Technical Report Server,1997.
[19]王学德. 高超声速稀薄气流非结构网格DSMC及并行算法研究[D]. 南京:南京航空航天大学,2006.
WANG Xuede. Research on unstructured grid DSMC and parallel algorithms for hypersonic dilute airflow[D]. Nanjing:Nanjing University of Aeronautics and Astronautics,2006.(in Chinese)
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