立方星的大量发射将加剧近地轨道的空间碎片问题。阻力帆技术利用气动阻力,可使得卫星被动离轨并进入大气层烧毁。离轨周期的计算需要对稀薄气动特性做出精确预测。本文采用NNW-DSMC软件,对立方星阻力帆离轨装置在不同高度下的稀薄绕流流场进行数值模拟,分析了气动特性的变化规律。结果表明,NNW-DSMC的计算结果与文献结果吻合良好（阻力系数与参考结果的相对误差小于1%,最大热流的相对误差在6%以内）,进一步验证了其计算精度和可靠性。将碰撞松弛数设置为温度的函数后,转动和振动温度降低,平动温度升高,流场总温度也增加了约10%。为增加模拟的保真度,应将松弛碰撞数设置为温度的函数。本文结果可为后续的立方星离轨动力学分析提供支撑。
The mass launch of Cubesat will exacerbate the problem of space debris in low Earth orbit. Drag sail technology uses aerodynamic drag to make satellites passively deorbit and burn up in the atmosphere. The calculation of deorbit period requires accurate prediction of rarefied aerodynamic characteristics. In this paper, by using NNW-DSMC software, the rarefied flow field around Cubesat drag sail at different altitudes is numerically simulated, and the variation of aerodynamic characteristics is analyzed. The results show that the calculated results of NNW-DSMC are in good agreement with those of literatures (the error between the drag coefficient and the reference result is less than 1% and the error of the maximum heat flux is within 6%). The accuracy and reliability are further verified. When the collision relaxation number is set as a function of temperature, the rotational and vibrational temperatures decrease, the translational temperature increases, and the total temperature of the flow field increases by about 10%. To increase the fidelity of the simulation, the collision relaxation number should be considered as a function of temperature. The results can provide support for the subsequent analysis of Cubesat deorbiting dynamics.
[1] 胡驰, 郭宁, 陈昊, 等. 立方星辅助离轨空气阻力帆技术研究进展[J]. 航天器环境工程, 2020, 37(1): 1-11.
[2] ARIEL BLACK, DAVID A SPENCER.DragSail systems for satellite deorbit and targeted reentry[J]. Journal of Space Safety Engineering, 2020, 7: 397-403.
[3] 王立武, 冯瑞, 张九双, 等. 增阻离轨装置气动特性的DSMC研究[J]. 空间碎片研究, 2021, 21(2): 46-51.
[4] ALBERTO M C, ISRAEL B S, SEBASTIAN T, et al.DSMC-SPARTA aerodynamic characterization of a deorbiting CubeSat[C]. AIP 31th International Symposium on Rarefied Gas Dynamics,2019.
[5] JIN LI, DINGWU JIANG, XIANGREN GENG, et al.Kinetic comparative study of rarefied-transitional flows[C]. 32nd International Symposium on Rarefied Gas Dynamics. Seoul, South Korea, 2022.
[6] JIN LI, DINGWU JIANG, XIANGREN GENG, et al. Kinetic comparative study on aerodynamic characteristics of hypersonic reentry vehicle from near-continuous flow to free molecular flow[J]. Advances in Aerodynamics, 2021, 1:217-226.
[7] G A BIRD.Molecular gas dynamics and the direct simulation of gas flows[M]. New York:Oxford University Press, 1994.
[8] YUAN HU, WENSHEN ZHAO, JIN LI, et al.Influence of DSMC collision model parameters on hypersonic chemically reacting flows[C]. 32nd International Symposium on Rarefied Gas Dynamics. Seoul, South Korea, 2022.
[9] IVANOV M S, KASHKOVSKY A V, VASHCHENKOV P V, et al.Parallel object-oriented software system for DSMC modeling of high-altitude aerothermodynamic problems[C]. AIP Conference Proceedings, 2011.
[10] S PLIMPTON,M GALLIS. SPARTA software documen-tation, Sandia National Laboratories[EB/OL]. http://sparta.sandia.gov,2023-07-20.
[11] M A GALLIS, J R TORCZYNSKI, S J PLIMPTON, et al. Direct simulation monte carlo: the quest for speed[C]. Xi’an,Proceedings of the 29th Rarefied Gas Dynamics (RGD) Symposium, 2014.
[12] T SCANLON, W CRAIG, K B MATTHEW, et al.Open source DSMC chemistry modelling for hypersonic flows[J]. AIAA Journal, 2014, 53(6) : 1670-1680.
