高超声速CO_(2)稀薄气体振动激发与DSMC方法实现  

Vibration Excitation of Hypersonic CO_(2) Rarefied Gasand Realization of DSMC Method

作　　者：谢东 王学德[1] XIE Dong;WANG Xuede(School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学能源与动力工程学院,江苏南京210094

出　　处：《弹道学报》2023年第2期87-95,共9页Journal of Ballistics

基　　金：基础加强重点研究项目。

摘　　要：针对火星独特的CO_(2)稀薄气体环境以及探测器高超声速进入火星过程中的高温真实气体效应,研究了CO_(2)多振动模式的激发特性。采用非结构网格和直接模拟蒙特卡洛法(Direct Simulation Monte Carlo method, DSMC),基于非谐振子振动激发模型,通过将CO_(2)离解能均分到4种振动模态,进而限制各模态最高振动能级,模拟了含CO_(2)的5组分17反应的高温稀薄真实气体化学反应模型。计算了“火星探路者”在火星大气环境65 km高度、进入速度为7 453 m/s、攻角为0°下的高温化学非平衡效应流场。结果表明:CO_(2)在激波后大量分解并消耗大量能量;迎风面激波中各组分占比与探测器物面特性等均与文献结果相符,证明了本文对于CO_(2)振动激发处理方法的可行性。在此基础上加入N_2组分,模拟火星大气8组分44基元化学反应流场,通过改变来流密度与马赫数分析了流场特性的变化。结果表明:随着来流密度减小,流场温度呈现先增加后减小的趋势,物面热流密度增大;来流马赫数增加使得流场温度和压力上升,物面热流密度提高但是热流密度系数变化幅度很小。In view of the unique CO_(2)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 CO_(2)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 CO_(2)was 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 CO_(2)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 7453 m/s and angle of attack of 0°in the Martian atmosphere.The results show that the CO_(2)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 CO_(2)vibration excitation treatment method.On this basis,the N 2 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.

关 键 词：高超声速 二氧化碳 振动激发 化学反应 直接模拟蒙特卡洛法 

分 类 号：V411[航空宇航科学与技术—航空宇航推进理论与工程]