NUMERICAL SIMULATION OF NON-EQUILIBRIUM FLOW-RADIATION CHARACTERISTICS AT HYPERSONIC SPEEDS
-
摘要: 飞行器高超声速飞行过程中所承受对流加热和辐射加热可能具有相当的量级, 因此合理准确预测气动加热需要将二者进行综合考虑. 文章发展了具有非玻尔兹曼电子能级分布和振动能级分布的高温空气碰撞辐射模型, 并耦合一维激波后流动方程计算不同飞行条件下激波后的非平衡流动特性, 采用逐线辐射输运模型计算获得激波后非平衡辐射特性、辐射强度和辐射输运通量, 深入比较分析了不同飞行高度和马赫数对非平衡流动和辐射输运过程的影响. 计算结果表明对于高空高马赫飞行条件, 其波后流动存在显著的热力学非平衡、化学非平衡和能级非平衡特征, 在近激波区域高振动能级和原子高束缚电子激发态明显低于玻尔兹曼分布. 在高空高马赫条件下真空紫外辐射占据主导地位, 主要是由高能原子束缚−束缚跃迁造成的. 随着高度和马赫数的下降, 激波层内气体解离和电离程度降低, 原子辐射贡献下降, 分子辐射贡献增加, 导致红外、可见光和紫外波段的辐射输运增强, 真空紫外辐射输运过程减弱.Abstract: The convective and radiative heating to which a hypersonic vehicle is subjected during hypersonic flight may be of comparable order of magnitude, so reasonably accurate prediction of aerodynamic heating requires a combination of both. In this paper, a high temperature air collisional-radiative model with non-Boltzmann electronical energy levels and vibrational energy levels distribution is developed, and coupled with the one-dimensional post-shock flow equations to calculate the non-equilibrium flow characteristics behind the shock front. The non-equilibrium radiation property, radiation intensity and radiation transfer of the post-shock flow are calculated by using the line-by-line radiation transfer model, which considers the bound-bound, bound-free, free-free radiative mechanisms of atoms and molecules in detail. The effects of flight altitudes and Mach numbers on non-equilibrium flow and radiation transfer process are deeply analyzed. The calculative results indicate that there are significant thermal non-equilibrium effect, chemical non-equilibrium effect and energy levels non-equilibrium effect existed in the post-shock flow for the high altitude and high Mach flight, and there are obvious under-population of the high vibrational energy levels and the high-lying electronical excited states in the near shock region, which are respectively caused by the rapid dissociation reaction of high vibrational states and the ionization processes of high-lying electronical states. Under the high altitude and high Mach conditions, the vacuum ultraviolet radiation is main contributor of radiative transfer process, which is mainly caused by the high energy atomic bound-bound radiative transition processes. With the decrease of altitude and Mach number, the degree of gas dissociation and ionization in the shock layer decreases, leading to the corresponding decrease of atomic radiative emission. Meanwhile, the number density of molecules increases and the contribution of molecular radiation increases, which leads to the enhancement of radiation transfer in infrared, visible and ultraviolet spectral bands, and the weakening of vacuum ultraviolet radiation transfer process.
-
表 1 碰撞辐射模型考虑的组分与能级
Table 1. Species and energy levels involved in CR model
Types Species Energy levels molecules N2 $ {X}^{1}{\sum }_{\mathrm{g}}^{ + } $(v = 0→67),$ {A}^{3}{\sum }_{u}^{ + } $, $ {B}^{3}{\prod }_{\mathrm{g}} $,
$ {W}^{3}{\Delta }_{u} $, $ {B{'}}^{3}{\sum }_{u}^{-} $, $ a{{'}}^{1}{\sum }_{u}^{-} $, $ {a}^{1}{\prod }_{\mathrm{g}} $,
$ {w}^{1}{\Delta }_{u} $, $ {G}^{3}{\Delta }_{\mathrm{g}} $, $ {C}^{3}{\prod }_{u} $, $ {E}^{3}{\sum }_{\mathrm{g}}^{ + } $O2 $ {X}^{3}{\sum }_{\mathrm{g}}^{-} $(v = 0→46),$ {a}^{1}{\Delta }_{\mathrm{g}} $,$ {b}^{1}{\sum }_{\mathrm{g}}^{ + } $,
$ {c}^{1}{\sum }_{u}^{-} $,$ {A{'}}^{3}{\Delta }_{u} $,$ {A}^{3}{\sum }_{u}^{ + } $,$ {B}^{3}{\sum }_{u}^{-} $,$ {f}^{1}{\sum }_{u}^{ + } $NO $ {X}^{2}\prod $,$ {a}^{4}\prod $,$ {A}^{2}{\sum }_{}^{ + } $,$ {B}^{2}\prod $,$ {b}^{4}{\sum }_{}^{-} $,
$ {C}^{2}\prod $,$ {D}^{2}{\sum }_{}^{ + } $,$ {B{'}}^{2}\Delta $,$ {E}^{2}{\sum }_{}^{ + } $,$ {F}^{2}\Delta $molecular ions N2+ $ {X}^{2}{\sum }_{\mathrm{g}}^{ + } $,$ {A}^{2}{\prod }_{u} $,$ {B}^{2}{\sum }_{u}^{ + } $,
$ {a}^{4}{\sum }_{u}^{ + } $,$ {D}^{2}{\prod }_{\mathrm{g}} $,$ {C}^{2}{\sum }_{u}^{ + } $O2+ $ {X}^{2}{\prod }_{\mathrm{g}} $,$ {a}^{4}{\prod }_{u} $,$ {A}^{2}{\prod }_{u} $,$ {b}^{4}{\sum }_{\mathrm{g}}^{-} $ NO+ $ {X}^{1}{\sum }_{}^{ + } $,$ {a}^{3}{\sum }_{}^{ + } $,$ {b}^{3}\prod $,$ {W}^{3}\Delta $,
$ {b{{'}}}^{3}{\sum }_{}^{-} $,$ {A{'}}^{1}{\sum }_{}^{ + } $,$ {W}^{1}\Delta $,$ {A}^{1}\prod $atoms N $ {{}_{}{}^{4}S}^{0} $, $ {}_{}{}^{2}D $, $ {}_{}{}^{2}P $, ··· (46 levels) O $ {}_{}{}^{3}P $, $ {}_{}{}^{1}D $, $ {}_{}{}^{1}S $, ··· (40 levels) atomic ions N+ $ {}_{}{}^{3}P $ O+ $ {{}_{}{}^{4}S}^{0} $ electron e− — 表 2 FIRE II飞行状态
Table 2. Flight conditions of FIRE II vehicle
Time/s Height/km Temperature/K Velocity/(m·s−1) 1634 76.42 195 11360 1643 53.04 276 10480 1648 42.14 267 8300 表 3 碰撞辐射模型考虑的辐射跃迁过程
Table 3. Radiative processes involved in CR model
Species Types Radiative transitions N bound-bound N(i)$ \leftrightarrow $N(j < i) + hv bound-free N+ + e−$ \leftrightarrow $N(i) + hv free-free N(i) + e−$ \leftrightarrow $N(i) + e− + hv O bound-bound O(i)$ \leftrightarrow $O(j < i) + hv bound-free O+ + e−$ \leftrightarrow $O(i) + hv free-free O(i) + e−$ \leftrightarrow $O(i) + e− + hv N2 bound-bound N2($ {B}^{3}{\prod }_{\mathrm{g}} $)$ \leftrightarrow $N2($ {A}^{3}{\sum }_{u}^{ + } $) + hv N2($ {C}^{3}{\prod }_{u} $)$ \leftrightarrow $N2($ {B}^{3}{\prod }_{\mathrm{g}} $) + hv N2($ {c}_{4}^{\text{'}}{\sum }_{u}^{ + } $)$ \leftrightarrow $N2($ {X}^{1}{\sum }_{\mathrm{g}}^{ + } $) + hv N2($ {c}_{3}^{\text{'}}{\prod }_{u} $)$ \leftrightarrow $N2($ {X}^{1}{\sum }_{\mathrm{g}}^{ + } $) + hv N2($ {b}^{1}{\prod }_{u} $)$ \leftrightarrow $N2($ {X}^{1}{\sum }_{\mathrm{g}}^{ + } $) + hv N2($ {b}_{}^{\text{'}1}{\sum }_{u}^{ + } $)$ \leftrightarrow $N2($ {X}^{1}{\sum }_{\mathrm{g}}^{ + } $) + hv N2($ {o}_{3}^{1}{\prod }_{u} $)$ \leftrightarrow $N2($ {X}^{1}{\sum }_{\mathrm{g}}^{ + } $) + hv bound-free continuum N2+ bound-bound N2+($ {B}^{2}{\sum }_{u}^{ + } $)$ \leftrightarrow $N2+($ {X}^{2}{\sum }_{\mathrm{g}}^{ + } $) + hv N2+($ {A}^{2}{\prod }_{u} $)$ \leftrightarrow $N2+($ {X}^{2}{\sum }_{\mathrm{g}}^{ + } $) + hv N2+($ {C}^{2}{\sum }_{u}^{ + } $)$ \leftrightarrow $N2+($ {X}^{2}{\sum }_{\mathrm{g}}^{ + } $) + hv NO bound-bound NO($ {B}^{2}\prod $r)$ \leftrightarrow $NO($ {X}^{2}\prod $r) + hv NO($ {A}^{2}{\sum }_{}^{ + } $)$ \leftrightarrow $NO($ {X}^{2}\prod $r) + hv NO($ {C}^{2}\prod $r)$ \leftrightarrow $NO($ {X}^{2}\prod $r) + hv NO($ {\mathrm{D}}^{2}{\sum }_{}^{ + } $)$ \leftrightarrow $NO($ {X}^{2}\prod $r) + hv NO($ {B{'}}^{2}\Delta $)$ \leftrightarrow $NO($ {X}^{2}\prod $r) + hv NO($ {E}^{2}{\sum }_{}^{ + } $)$ \leftrightarrow $NO($ {X}^{2}\prod $r) + hv O2 bound-bound O2($ {B}^{3}{\sum }_{u}^{-} $)$ \leftrightarrow $O2($ {X}^{3}{\sum }_{\mathrm{g}}^{-} $) + hv bound-free continuum -
[1] 林烈, 吴彬, 吴承康, 高温气流中材料表面催化特性研究. 空气动力学学报, 2001, 19(4): 407-413 (Lin Lie, Wu Bin, Wu Chengkang. Studies on surface catalytic effect of materials in a high-temperature gas flow. Acta Aerodynamica Sinica, 2001, 19(4): 407-413 (in Chinese)Lin Lie, Wu Bin, Wu Chengkang. Studies on surface catalytic effect of materials in a high-temperature gas flow. Acta Aerodynamica Sinica, 2001, 19(4): 407-413 (in Chinese) [2] Anderson JD. Hypersonic and High Temperature Gas Dynamics. McGraw-Hill, 2006 [3] 欧阳水吾, 谢中强. 高温非平衡空气绕流. 北京: 国防工业出版社, 2001 (Ouyang Shuiwu, Xie Zhongqiang. High Temperature Nonequilibrium Air Flow. Beijing: National Defense Industry Press, 2001 (in Chinese)Ouyang Shuiwu, Xie Zhongqiang. High Temperature Nonequilibrium Air Flow. Beijing: National Defense Industry Press, 2001 (in Chinese) [4] 王国雄. 弹头技术. 北京: 中国宇航出版社, 1993 (Wang Guoxiong. Warhead Technology. Beijing: China Astronautic Publishing House, 1993 (in Chinese)Wang Guoxiong. Warhead Technology. Beijing: China Astronautic Publishing House, 1993 (in Chinese) [5] Jo SM, Kwon OJ, Kim JG. Electronic-state-resolved analysis of high-enthalpy air plasma flows. Physical Review E, 2019, 100(3): 033203 doi: 10.1103/PhysRevE.100.033203 [6] Lin C, Xu A, Zhang G, et al. Polar-coordinate lattice Boltzmann modeling of compressible flows. Physical Review E, 2014, 89(1): 013307 doi: 10.1103/PhysRevE.89.013307 [7] Lin C, Luo KH, Fei L, et al. A multi-component discrete Boltzmann model for nonequilibrium reactive flows. Scientific Reports, 2017, 7(1): 14580 doi: 10.1038/s41598-017-14824-9 [8] Lin C, Luo KH. MRT discrete Boltzmann method for compressible exothermic reactive flows. Computers and Fluids, 2018, 166: 176-183 [9] Lin C, Luo KH. Discrete Boltzmann modeling of unsteady reactive flows with nonequilibrium effects. Physical Review E, 2019, 99(1): 012142 doi: 10.1103/PhysRevE.99.012142 [10] Lin C, Su X, Zhang Y. Hydrodynamic and thermodynamic nonequilibrium effects around shock waves: based on a discrete Boltzmann method. Entropy, 2020, 22(12): 1397 [11] Su X, Lin C. Nonequilibrium effects of reactive flow based on gas kinetic theory. Communications in Theoretical Physics, 2022, 74(3): 035604 doi: 10.1088/1572-9494/ac53a0 [12] Park C. On convergence of computation of chemically reacting flows//AIAA 23rd Aerospace Sciences Meeting, Nevada, January 14-17, 1985 [13] Gupta RN, Yos JM, Thompson RA, et al. A review of reaction rates and thermodynamic and transport properties for an 11-species air model for chemical and thermal nonequilibrium calculations to 30000 K. NASA-RP-1232, 1990 [14] Dunn MG, Kang S. Theoretical and experimental studies of reentry plasmas. NASA CR-2232, 1973 [15] Park C. Thermochemical relaxation in shock tunnels. Journal of Thermophysics and Heat Transfer, 2006, 20(4): 689-698 doi: 10.2514/1.22719 [16] Dobrov Y, Gimadiev V, Karpenko A, et al. Numerical simulation of hypersonic flow with non-equilibrium chemical reactions around sphere. Acta Astronautica, 2021, 194(8): 468-479 [17] Bultel A, Cheron B, Bourdon A. Collisional-radiative model in air for earth re-entry problems. Physics of Plasmas. 2006, 13(4): 043502 [18] Marco P, Magin T, Bourdon A. Fire II flight experiment analysis by means of a collisional-radiative model. Journal of Thermophysics and Heat Transfer, 2009, 23(2): 236-248 doi: 10.2514/1.39034 [19] Capitelli M, Armenise I, Bruno D. Non-equilibrium plasma kinetics: a state-to-state approach. Plasma Sources Science and Technology, 2007, 16(1): 30-44 doi: 10.1088/0963-0252/16/1/S03 [20] Yaowen Du, Surong Sun, Meijing Tan, et al. Non-equilibrium simulation of energy relaxation for earth reentry utilizing a collisional-radiative model. Acta Astronautica, 2022, 193: 521-537 doi: 10.1016/j.actaastro.2022.01.034 [21] Park C. Nonequilibrium air radiation (NEQAIR) program: User’s manual. NASA TM 86707, 1985 [22] Whiting EE, Park C, Liu Y, et al. NEQAIR96, nonequilibrium and equilibrium radiative transport and spectra program: user’s manual. NASA RP 1389, 1996 [23] Chambers LH. Predicting radiative heat transfer in thermochemical nonequilibrium flow fields: theory and user’s manual for the LORAN code. NASA TM 4564, 1994 [24] Laporta V, Bruno D. Electron-vibration energy exchange models in nitrogen-containing plasma flows. The Journal of Chemical Physics, 2013, 138(10): 104319 [25] Armenise I, Capitelli M, Colonna G, et al. Nonequilibrium vibrational kinetics in the boundary layer of re-entering bodies. Journal of Thermophysics and Heat Transfer, 1996, 10(3): 397-405 [26] Esposito F, Armenise I, Capitta G, et al. O–O2 state-to-state vibrational relaxation and dissociation rates based on quasiclassical calculations. Chemical Physics, 2008, 351(1-3): 91-98 [27] Lotz W. Electron-impact ionization cross-sections and ionization rate coefficients for atoms and ions from hydrogen to calcium. Z Physik, 1968, 216(3): 241-247 [28] Drawin HW. Influence of atom-atom collisions on the collisional-radiative ionization and recombination coefficients of hydrogen plasmas. Z Physik, 1969, 225(5): 483-493 [29] Bose D, Candler GV. Thermal rate constants of the O2 + N→NO + O reaction based on the A2′and A4′ potential-energy surfaces. The Journal of Chemical Physics, 1997, 107(16): 6136-6145 [30] Peterson JR, Le Padellec A, Danared H, et al. Dissociative recombination and excitation of N2 + : Cross sections and product branching ratios. The Journal of Chemical Physics, 1998, 108(5): 1978-1988 [31] Peverall R, Rosén S, Peterson JR, et al. Dissociative recombination and excitation of O2 + : Cross sections, product yields and implications for studies of ionospheric airglows. The Journal of Chemical Physics, 2001, 114(15): 6679-6689 [32] Motapon O, Fifirig M, Florescu A, et al. Reactive collisions between electrons and NO + ions: Rate coefficient computations and relevance for the air plasma kinetics. Plasma Sources Sci Technol, 2006, 15(1): 23-32 [33] Annaloro J, Bultel A. Vibrational and electronic collisional-radiative model in air for Earth entry problems. Physics of Plasmas, 2014, 21(12): 123512 doi: 10.1063/1.4904817 [34] Cauchon DL. Radiative heating results from the Fire 2 flight experiment at a reentry velocity of 11.4 kilometers per second. NASA Ames Research Center TM X-1402, Moffett Field, CA, 1967 [35] Cornette ES. Forebody temperature and calorimeter heating rates measured during project Fire II reentry at 11.35 km/s. Tech. Mem. X-1305. NASA, 1966 [36] Kramida A, Ralchenko Y, Reader J. Atomic spectra database. NIST.https://www.nist.gov/pml/atomic-spectra-database [retrieved Oct. 2022 [37] Cunto W. TOPbase at the CDS. http://vizier.u--strasbg.fr/topbase/topbase. html [retrieved Sept. 2006 [38] Johnston CO. Nonequilibrium shock-layer radiative heating for earth and titan entry. [PhD Thesis]. Virginia Polytechnic Institute and State University, 2006 [39] Peach G. Continuous absorption coefficients for non-hydrogenic atoms. Monthly Notices of the Royal Astronomical Society. 1962, 124(5), 371–381 [40] Laux CO, Kruger CH. Arrays of radiative transition probabilities for the N2 first and second positive, no beta and gamma, N2 + first negative, and O2 Schumann-Runge band systems. Journal of Quantitative Spectroscopy and Radiative Transfer, 1992, 48(1), 9–24 [41] Chauveau S, Perrin MY, Riviere PH, et al. Contributions of diatomic molecular electronic systems to heated air radiation. Journal of Quantitative Spectroscopy and Radiative Transfer, 2022, 72(4), 503–530 [42] Kovacs I. Rotational structure in the spectra of diatomic molecules. Physics Today, 1972, 25(11), 54–54 [43] Earls LT. Intensities in Π2−Σ2 transitions in diatomic molecules. Physical Review, 1935, 48(5), 423–424 [44] Jo SM, Kwon OJ, Kim JG. Stagnation-point heating of Fire II with a non-Boltzmann radiation model. International Journal of Heat and Mass Transfer, 2020, 153: 119566 doi: 10.1016/j.ijheatmasstransfer.2020.119566 [45] Cruden BA. Electron density measurement in reentry shocks for lunar return. Journal of Thermophysics and Heat Transfer, 2012, 26: 222-230 doi: 10.2514/1.T3796 [46] Chauveau S, Perrin MY, P Rivière, et al. Contributions of diatomic molecular electronic systems to heated air radiation. Journal of Quantitative Spectroscopy and Radiative Transfer, 2002, 72(4): 503-530 doi: 10.1016/S0022-4073(01)00141-8 [47] Zander F, Gollan RJ, Jacobs PA, Morgan RG. Hypervelocity shock standoff on spheres in air. Shock Waves, 2014, 24(2): 171-178 -