LARGE EDDY SIMULATION OF HYPERSONIC COMBUSTION BASED ON DYNAMIC ZONE CONCEPT
-
摘要: 本文基于动态分区概念开展了亿级网格的高马赫数全尺寸超燃冲压发动机内外流耦合一体化改进延迟分离涡(IDDES)模拟研究. 研究建立了包括动态分区火焰面湍流燃烧模型(DZFM)、分区自适应化学(Z-DAC)和分区并行自适应建表(Z-ISAT)的完整动态分区燃烧模拟框架, 并通过1.15亿网格的马赫数12 REST标准高超声速燃烧室模型初步验证了分区模拟框架的保真性. DZFM通过分区解耦的思想既准确表征了当地湍流化学交互作用关系, 又有效提升了整场湍流燃烧的计算效率. Z-DAC和Z-ISAT通过在分区框架内对化学反应机理进行动态实时简化和建表查询, 可进一步提升当前分区内化学反应的求解效率. 基于1.25和1.4亿网格动态分区框架对比分析了马赫数10条件下中心支板(strut)和壁面撑挡型(pylon)两类构型氢气高超声速燃烧室特性. 支板或撑挡结构均诱发了明显的边界层分离和头部回流区, 由此两种燃烧室均出现了较长区域的喷注点前部燃烧现象. 基于Borghi图的数值分析表明当前氢气高超声速燃烧室中广泛存在扩散控制为主的火焰面模式, 效率提升的瓶颈在于高效增混. 壁面撑挡燃烧室具有较高的穿透深度和近场混合效率, 因而燃烧效率高于净推力准则80%, 相应的比冲1234 s也远高于中心支板燃烧室的437 s. 分区自适应化学方法在将近一半的计算域上降低了反应求解计算代价, 特别是在无燃料区反应机理的简化幅度更加明显. 相比与传统的有限速率PaSR模型, DZFM模型实现了高达11倍的加速比.Abstract: Based on the concept of dynamic zone partition, improved delayed detached eddy simulation (IDDES) modeling of high-Ma full-scale scramjets with more than 100 million cells was conducted for the integrated internal and external flow fields. A complete dynamic zonal combustion modeling framework was established, including dynamic zone flamelet model (DZFM), zonal dynamic adaptive chemistry (Z-DAC), and zonal in situ adaptive tabulation (Z-ISAT). The fidelity of the zonal modeling framework is preliminarily verified by the 115-million-cell modeling of a benchmark hypersonic combustor named REST, which was designed to operate at Mach 12. Through the idea of local flow-chemistry decoupling within each zone, DZFM not only accurately represents the local turbulence-chemistry interaction but also effectively improves the computational efficiency of turbulent combustion in the whole field. Z-DAC and Z-ISAT can further improve the resolving efficiency of chemical reactions in each zone by dynamically reducing the chemical mechanism and tabulating the thermochemical states. Then based on 125 and 140 million cells, respectively, the characteristics of hydrogen-fueled strut and pylon hypersonic combustors were comparatively analyzed for Mach 10. Both the pylon and strut structures induce obvious boundary layer separation and fore-body recirculation zone, resulting in long pre-combustion regions in front of the injection point in both combustors. Numerical analysis based on the Borghi diagram shows that the diffusion-dominated flame mode widely exists in the current hydrogen-fueled hypersonic combustor, and the bottleneck of efficiency improvement lies in efficient mixing. The pylon combustor has higher jet penetration depth and better near-field mixing, and thus the combustion efficiency of 80% is above the criterion of achieving net thrust. The specific impulse of 1234 s in the pylon combustor is also much higher than the 437 s in the strut combustor. Z-DAC reduces the computational cost of reaction systems in nearly half of the computational domain, especially in the fuel-free regions. Compared with the traditional finite-rate PaSR model, the DZFM model achieves an acceleration ratio of up to 11.
-
表 1 测试飞行工况参数
Table 1. Flight test conditions
Freestream Fuel stream (mass fraction YN2: 0.767, YO2: 0.233) (mass fraction YH2: 1.0) Ma H/km T/K p/Pa U/(m·s−1) q/Pa Pt/Pa Tt/K Qfuel/(kg·s−1) Tt/K Ma 10 40 250 287 3172 20099 2.7 × 107 4333.5 0.023 298 1 表 2 壁面撑挡和中心支板燃烧室总体性能对比
Table 2. Overall performance comparison between pylon and strut combustors
Global performance Pylon combustor Strut combustor air captured rate/(kg·s−1) 0.97619 0.79284 fuel flow rate/(kg·s−1) 0.028431 0.023091 inviscid Thrust/N 650.5093 477.038 viscous Drag/N 306.2568 377.9552 net Thrust/N 344.2525 99.0828 combustion efficiency 0.83833 0.60653 isolator pressure/kPa 5.1081 5.4449 peak pressure ratio 16.6474 11.1863 specific Impulse/s 1234.2698 437.4018 表 3 DZFM模型与PaSR模型计算1 ms物理时间对应的CPU时间
Table 3. CPU time of DZFM and PASR model calculation of 1 millisecond physical time
No reaction acceleration Z-DAC Z-ISAT Z-DAC + Z-ISAT PaSR 582.61 × 504 CPU h 468.16 × 504 CPU h 332.92 × 504 CPU h 291.30 × 504 CPU h DZFM 52.02 × 504 CPU h 49.42 × 504 CPU h 49.42 × 504 CPU h 48.59 × 504 CPU h -
[1] Marshall L, Bahm C, Corpening G. Overview with results and lessons learned of the x-43 a mach 10 flight//AIAA/CIRA 13 th International Space Planes and Hypersonics Systems and Technologies Conference, 2005 [2] Smart MK, Tetlow MR. Orbital delivery of small payloads using hypersonic airbreathing propulsion. Journal of Spacecraft and Rockets, 2009, 46(1): 117-125 doi: 10.2514/1.38784 [3] Rogers RC, Shih AT, Tsai CY. Scramjet tests in a shock tunnel at flight mach 7, 10, and 15 conditions. AIAA Paper, 2011-3241 [4] Barkmeyer D, Starkey R, Lewis M. Inverse waverider design for inward turning inlets//41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2005 [5] Gai SL. Free piston shock tunnels developments and capabilities. Aerospace, 1992, 29(1): 1-41 doi: 10.1016/0376-0421(92)90002-Y [6] Chan WYK, Razzaqi SA, Turner JC, et al. Freejet testing of the hifire 7 scramjet flowpath at mach 7.5. Journal of Propulsion and Power, 2018, 34(4): 844-853 doi: 10.2514/1.B36652 [7] Curran D, Wheatley V, Smart M. Investigation of combustion mode control in a mach 8 shape-transitioning scramjet. AIAA Journal, 2019, 57(7): 2977-2988 doi: 10.2514/1.J057999 [8] Suraweera MV, Smart MK. Shock-tunnel experiments with a mach 12 rectangular-to-elliptical shape-transition scramjet at offdesign conditions. Journal of Propulsion and Power, 2009, 25(3): 555-564 doi: 10.2514/1.37946 [9] Doherty LJ, Smart MK, Mee DJ. Experimental testing of an airframe-integrated three-dimensional scramjet at mach 10. AIAA Journal, 2015, 53(11): 3196-3207 doi: 10.2514/1.J053785 [10] Landsberg WO, Wheatley V, Smart MK, et al. Enhanced supersonic combustion targeting combustor length reduction in a mach 12 scramjet. AIAA Journal, 2018, 56(10): 3802-3807 doi: 10.2514/1.J057417 [11] Barth JE. Mixing and combustion enhancement in a mach 12 shape-transitioning scramjet engine. [PHD Thesis]. Brisbane: The University of Queensland, 2014 [12] Wise DJ, Smart MK. Experimental investigation of a three-dimensional scramjet engine at Mach 12//20th AIAA International Space Planes and Hypersonic Systems and Technologies Conference, 2015 [13] Shenoy RR, Drozda TG, Norris AT, et al. Comparison of mixing characteristics for several fuel injectors at Mach 8, 12, and 15 hypervelocity flow conditions//2018 Joint Propulsion Conference, July 2018 [14] Bakos R, Tamagno J, Trucco R, et al. Mixing and combustion studies using discrete orifice injection at hypervelocity flight conditions. Journal of Propulsion and Power, 1992, 8(6): 1290-1296 doi: 10.2514/3.11475 [15] Yao W, Chen L. Large eddy simulation of rest hypersonic combustor based on dynamic zone flamelet model//AIAA Propulsion and Energy 2020 Forum, 2020 [16] Yao W, Wu K, Fan XJ. Influences of domain symmetry on supersonic combustion modeling. Journal of Propulsion and Power, 2019, 35(2): 451-465 doi: 10.2514/1.B37227 [17] Yao W, Lu Y, Wu K, et al. Modeling analysis of an actively cooled scramjet combustor under different kerosene/air ratios. Journal of Propulsion and Power, 2018, 34(4): 975-991 doi: 10.2514/1.B36866 [18] Yao W, Yuan YM, Li XP, et al. Comparative study of elliptic and round scramjet combustors fueled by RP-3. Journal of Propulsion and Power, 2018, 34(3): 772-786 doi: 10.2514/1.B36721 [19] Fan ZQ, Liu WD, Sun MB, et al. Theoretical analysis of flamelet model for supersonic turbulent combustion. Science China Technological Sciences, 2011, 55(1): 193-205 [20] 孙明波, 范周琴, 梁剑寒等. 部分预混超声速燃烧火焰面模式研究综述. 力学进展, 2010, 40(6): 634-641 (Sun Mingbo, Fan Zhouqin, Liang Jianhan, et al. Evalutaion of partially permixed flamelet approach in supersonic combustion. Anvances in Mechanics, 2010, 40(6): 634-641 (in Chinese) doi: 10.6052/1000-0992-2010-6-lxjzJ2009-127 [21] Davidenko D, Gökalp I, Dufour E, et al. Numerical simulation of hydrogen supersonic combustion and validation of computational approach//12th AIAA International Space Planes and Hypersonic Systems and Technologies, 2003 [22] Golovitchev VI, Nordin N, Jarnicki R, et al. 3-D diesel spray simulations using a new detailed chemistry turbulent combustion model. SAE Technical Paper, 2000 [23] Magnussen B. On the structure of turbulence and a generalized eddy dissipation concept for chemical reaction in turbulent flow//19th Aerospace Sciences Meeting, 1981 [24] Legiery JP, Poinsot T, Veynante D. Dynamically thickened flame LES model for premixed and non-premixed turbulent combustion//Proceedings of the 2000 Summer Program, 2000: 157-168 [25] Calhoon W, Menon S. Linear-eddy subgrid model for reacting large-eddy simulations - heat release effects//35th Aerospace Sciences Meeting and Exhibit. American Institute of Aeronautics and Astronautics, 1997 [26] Peters N. Laminar flamelet concepts in turbulent combustion//21st Symposium (International) on Combustion, 1986: 1231-1250 [27] Bray K. Laminar flamelets in turbulent combustion modeling. Combustion Science and Technology, 2016, 188(9): 1372-1375 doi: 10.1080/00102202.2016.1195819 [28] Cook DJ, Pitsch H, Chen JH, et al. Flamelet-based modeling of auto-ignition with thermal inhomogeneities for application to hcci engines. Proceedings of the Combustion Institute, 2007, 31(2): 2903-2911 doi: 10.1016/j.proci.2006.07.252 [29] Klimenkoa AY, Bilger RW. Conditional momen closure for turbulent combustion. Progress in Energy and Combustion Science, 1999, 25: 595-687 doi: 10.1016/S0360-1285(99)00006-4 [30] Ramanujachari V, Balakrishna S. Probability density function approach to non-premixed turbulent flames. Indian Journal of Pure and Applied Mathematics, 2000, 31: 1339-1351 [31] Huang C, Lipatnikov AN. Comparison of presumed PDF models of turbulent flames. Journal of Combustion, 2012, 2012: 1-15 [32] Pope SB. PDF methods for turbulent reactive flows. Progress in Energy and Combustion Science, 1985, 11: 119-192 doi: 10.1016/0360-1285(85)90002-4 [33] Pierce CD, Moin P. Progress-variable approach for large-eddy simulation of non-premixed turbulent combustion. Journal of Fluid Mechanics, 2004, 504: 73-97 doi: 10.1017/S0022112004008213 [34] Williams FA. Turbulent combustion//The Mathematics of Combustion, 1985, doi: 10.1137/1.9781611971064.Ch3 [35] Oijen JAV, Goey LPHD. Modelling of premixed laminar flames using flamelet-generated manifolds. Combustion Science and Technology, 2000, 161(1): 113-137 doi: 10.1080/00102200008935814 [36] Kundu P, Pei Y, Wang M, et al. Evaluation of turbulence-chemistry interaction under diesel engine conditions with multi-flamelet rif model. Atomization and Sprays, 2014, 24: 779-800 doi: 10.1615/AtomizSpr.2014010506 [37] Pitsch H, Barths H, Peters N. Three-dimensional modeling of nox and soot formation in di-diesel engines using detailed chemistry based on the interactive flamelet approach//International Fall Fuels & Lubricants Meeting& Exposition, San Antonio, Texas, 1996 [38] 刘昆, 张育林. 液体火箭发动机燃烧室的一种分区模型. 航空动力学报, 2002, 17(1): 135-139 (Liu Kun, Zhang Yulin. An innovative partition model of liquid rocket engine comubsution chambers. Journal of Aerospace Power, 2002, 17(1): 135-139 (in Chinese) doi: 10.3969/j.issn.1000-8055.2002.01.025 [39] Ge HW, Juneja H, Shi Y, et al. A two-zone multigrid model for si engine combustion simulation using detailed chemistry. Journal of Combustion, 2010, 2010: 1-12 [40] Saeed K, Stone CR. The modelling of premixed laminar combustion in a closed vessel. Combustion Theory and Modelling, 2006, 8(4): 721-743 [41] Kodavasal J, Keum SH, Babajimopoulos A. An extended multi-zone combustion model for pci simulation. Combustion Theory and Modelling, 2011, 15(6): 893-910 doi: 10.1080/13647830.2011.578663 [42] Men YF, Haskara I, Zhu GM. Multi-zone reaction-based modeling of combustion for multiple-injection diesel engines. International Journal of Engine Research, 2018, 21(6): 1012-1025 [43] Perini F. High-dimensional, unsupervised cell clustering for computationally efficient engine simulations with detailed combustion chemistry. Fuel, 2013, 106: 344-356 doi: 10.1016/j.fuel.2012.11.015 [44] Zhou DZ, Tay KL, Li H, et al. Computational acceleration of multi-dimensional reactive flow modelling using diesel/biodiesel/jet-fuel surrogate mechanisms via a clustered dynamic adaptive chemistry method. Combustion and Flame, 2018, 196: 197-209 doi: 10.1016/j.combustflame.2018.06.008 [45] Dai M, Xuna L, Liang Z. Detailed chemaical micro fluid combustion models for natural gas fueled hcci engines//19th International Conference on Computational Combustion, Stockholm, Sweden, 2017 [46] Raju M, Wang MJ, Dai MH, et al. Acceleration of detailed chemical kinetics using multi-zone modeling for cfd in internal combustion engine simulations. SAE Technical Paper Series, 2012 [47] Ingenito A, Flora M, Bruno C. LES modeling of scramjet combustion//44th AIAA Aerospace Sciences Meeting and Exhibit, 2006 [48] Liang L, Stevens JG, Farrell JT. A dynamic multi-zone partitioning scheme for solving detailed chemical kinetics in reactive flow computations. Combustion Science and Technology, 2009, 181(11): 1345-1371 doi: 10.1080/00102200903190836 [49] Wu H, See YC, Wang Q, et al. A pareto-efficient combustion framework with submodel assignment for predicting complex flame configurations. Combustion and Flame, 2015, 162(11): 4208-4230 doi: 10.1016/j.combustflame.2015.06.021 [50] Wu H, See YC, Wang Q, et al. A fidelity adaptive modeling framework for combustion systems based on model trust-region//53rd AIAA Aerospace Sciences Meeting, 2015 [51] Yao W, Fan XJ. Application of dynamic zone flamelet model to a gh2/go2 rocket combustor//AIAA Propulsion and Energy 2019 Forum, 2019 [52] Cuoci A, Frassoldati A, Faravelli T, et al. Kinetic modeling of soot formation in turbulent nonpremixed flames. Environmental Engineering Science, 2008, 25(10): 1407-1422 doi: 10.1089/ees.2007.0193 [53] Cleary M, Kent J. Modelling of species in hood fires by conditional moment closure. Combustion and Flame, 2005, 143(4): 357-368 doi: 10.1016/j.combustflame.2005.08.013 [54] Young KJ, Moss JB. Modelling sooting turbulent jet flames using an extended flamelet technique. Combustion Science and Technology, 1995, 105(1-3): 33-53 doi: 10.1080/00102209508907738 [55] Thornber B, Bilger RW, Masri AR, et al. An algorithm for LES of premixed compressible flows using the conditional moment closure model. Journal of Computational Physics, 2011, 230(20): 7687-7705 doi: 10.1016/j.jcp.2011.06.024 [56] Schwer DA, Lu P, Green WH. An adaptive chemistry approach to modeling complex kinetics in reacting flows. Combustion and Flame, 2003, 133(4): 451-465 doi: 10.1016/S0010-2180(03)00045-2 [57] Liang L, Stevens JG, Farrell JT. A dynamic adaptive chemistry scheme for reactive flow computations. Proceedings of the Combustion Institute, 2009, 32(1): 527-534 doi: 10.1016/j.proci.2008.05.073 [58] Lu TF, Law CK. Toward accommodating realistic fuel chemistry in large-scale computations. Progress in Energy and Combustion Science, 2009, 35(2): 192-215 doi: 10.1016/j.pecs.2008.10.002 [59] Yao W. Kerosene-fueled supersonic combustion modeling based on skeletal mechanisms. Acta Mechanica Sinica, 2019, 35(6): 1155-1177 doi: 10.1007/s10409-019-00891-w [60] Lu TF, Law CK. A directed relation graph method for mechanism reduction. Proceedings of the Combustion Institute, 2005, 30(1): 1333-1341 doi: 10.1016/j.proci.2004.08.145 [61] Pepiotdesjardins P, Pitsch H. An efficient error-propagation-based reduction method for large chemical kinetic mechanisms. Combustion and Flame, 2008, 154(1-2): 67-81 doi: 10.1016/j.combustflame.2007.10.020 [62] Pope SB. Computationally efficient implementation of combustion chemistry usingin situadaptive tabulation. Combustion Theory and Modelling, 1997, 1(1): 41-63 doi: 10.1080/713665229 [63] Yang B, Pope SB. Treating chemistry in combustion with detailed mechanisms - in situ adaptive tabulation in principal directions - premixed combustion. Combustion and Flame, 1998, 112: 85-112 doi: 10.1016/S0010-2180(97)81759-2 [64] Liu BJD, Pope SB. The performance ofin situadaptive tabulation in computations of turbulent flames. Combustion Theory and Modelling, 2005, 9(4): 549-568 doi: 10.1080/13647830500307436 [65] 肖保国. 碳氢燃料简化动力学模型和当地自适应建表方法在超燃并行计算中的应用. [博士论文]. 中国空气动力研究与发展中心, 2009Xiao Baoguo. Implementation of reduced chemical kinetics of hydrocarbon fuels and in situ adaptive tabulation in parallel computations of supersonic combustion. [PhD Thesis]. China Aerodynamics Research and Development Center, 2009 (in Chinese) [66] Lu LY, Lantz SR, Ren ZY, et al. Computationally efficient implementation of combustion chemistry in parallel PDF calculations. Journal of Computational Physics, 2009, 228(15): 5490-5525 doi: 10.1016/j.jcp.2009.04.037 [67] Yuan YM, Zhang TC, Yao W, et al. Characterization of flame stabilization modes in an ethylene-fueled supersonic combustor using time-resolved CH* chemiluminescence. Proceedings of the Combustion Institute, 2017, 36(2): 2919-2925 doi: 10.1016/j.proci.2016.07.040 [68] Sankaran V, Genin F, Menon S. Subgrid mixing modeling for large eddy simulation of supersonic combustion//42nd AIAA Aerospace Sciences Meeting and Exhibit. American Institute of Aeronautics and Astronautics, 2004 [69] Piomelli U. Large-eddy and direct simulation of turbulent flows//Introduction to Turbulence Modelling, Von Karman Institute, Belgium, 2004 [70] Yao W. On the application of dynamic zone flamelet model to large eddy simulation of supersonic hydrogen flame. International Journal of Hydrogen Energy, 2020, 45(41): 21940-21955 doi: 10.1016/j.ijhydene.2020.05.189 [71] Jones WP, Whitelaw JH. Calculation methods for reacting turbulent flows: A review. Combustion and Flame, 1982, 48: 1-26 doi: 10.1016/0010-2180(82)90112-2 [72] Pierce CD, Moin P. A dynamic model for subgrid-scale variance and dissipation rate of a conserved scalar. Physics of Fluids, 1998, 10(12): 3041-3044 doi: 10.1063/1.869832 [73] Triantafyllidis A, Mastorakos E. Implementation issues of the conditional moment closure model in large eddy simulations. Flow, Turbulence and Combustion, 2009, 84(3): 481-512 [74] Nichols RH. Turbulence models and their application to complex flows. [PhD Thesis]. University of Alabama at Birmingham, 2014 [75] Spalart PR. Detached-eddy simulation. Annual Review of Fluid Mechanics, 2009, 41(1): 181-202 doi: 10.1146/annurev.fluid.010908.165130 [76] Shur ML, Spalart PR, Strelets MK, et al. A hybrid rans-LES approach with delayed-des and wall-modelled LES capabilities. International Journal of Heat and Fluid Flow, 2008, 29(6): 1638-1649 doi: 10.1016/j.ijheatfluidflow.2008.07.001 [77] Spalart PR, Allmaras SR. A one-equation turbulence model for aerodynamic flows. AIAA-92-0439, 1992 [78] Spalart PR, Deck S, Shur ML, et al. A new version of detached-eddy simulation, resistant to ambiguous grid densities. Theoretical and Computational Fluid Dynamics, 2006, 20(3): 181-195 doi: 10.1007/s00162-006-0015-0 [79] McLinden MO, Klein SA, Perkins RA. An extended corresponding states model for the thermal conductivity of refrigerants and refrigerant mixtures. International Journal of Refrigeration, 2000, 23: 43-63 doi: 10.1016/S0140-7007(99)00024-9 [80] Chase MW. Nist-janaf thermochemical tables. (4th ed.). Journal of Physical and Chemical Reference Data, 1998, 9: 1-1952 [81] Kee RJ, Rupley FM, Miller JA. Chemkin-il: A fortran chemical kinetics package for the analysis of gas-phase chemical kinetics. Sandia National Laboratories, 1989 [82] Mathur S, Tondon PK, Saxena SC. Thermal conductivity of binary, ternary and quaternary mixtures of rare gases. Molecular Physics, 1967, 12(6): 569-579 doi: 10.1080/00268976700100731 [83] Weller HG, Tabor G, Jasak H, et al. A tensorial approach to computational continuum mechanics using object-oriented techniques. Computers in Physics, 1998, 12: 620 [84] Lee YC, Yao W, Fan XJ. Low-dissipative hybrid compressible solver designed for large-eddy simulation of supersonic turbulent flows. AIAA Journal, 2018, 56(8): 3086-3096 doi: 10.2514/1.J056404 [85] Chen SS, Yan C, Xiang XH. Effective low-mach number improvement for upwind schemes. Computers & Mathematics with Applications, 2018, 75(10): 3737-3755 [86] Yao W, Wang J, Lu Y, et al. Full-scale detached eddy simulation of kerosene fueled scramjet combustor based on skeletal mechanism//20th AIAA International Space Planes and Hypersonic Systems and Technologies Conference, 2015 [87] Wu K, Zhang P, Yao W, et al. Numerical investigation on flame stabilization in dlr hydrogen supersonic combustor with strut injection. Combustion Science and Technology, 2017, 189(12): 2154-2179 doi: 10.1080/00102202.2017.1365847 [88] Yao W, Lu Y, Li XP, et al. Improved delayed detached eddy simulation of a high-ma active-cooled scramjet combustor based on skeletal kerosene mechanism//52nd AIAA/SAE/ASEE Joint Propulsion Conference, 2016. [89] Wu K, Yao W, Fan XJ. Development and fidelity evaluation of a skeletal ethylene mechanism under scramjet-relevant conditions. Energy & Fuels, 2017, 31(12): 14296-14305 [90] Gritskevich MS, Garbaruk AV, Schütze J, et al. Development of ddes and iddes formulations for the k-ω shear stress transport model. Flow, Turbulence and Combustion, 2011, 88(3): 431-449 [91] Jachimowski CJ. An analysis of combustion studies in shock expansion tunnels and reflected shock tunnels. NASA Langley Technical Report Server, No. 19920019131, 1998 [92] Saarlas M. Reference temperature method for computing displacement thickness. AIAA Journal, 1964, 2(11): 2056-2057 doi: 10.2514/3.2741 [93] Lu TF, Yoo CS, Chen JH, et al. Three-dimensional direct numerical simulation of a turbulent lifted hydrogen jet flame in heated coflow: A chemical explosive mode analysis. Journal of Fluid Mechanics, 2010, 652: 45-64 doi: 10.1017/S002211201000039X [94] Wu WT, Piao Y, Xie Q, et al. Flame diagnostics with a conservative representation of chemical explosive mode analysis. AIAA Journal, 2019, 57(4): 1355-1363 doi: 10.2514/1.J057994 [95] Smart MK. How much compression should a scramjet inlet do? AIAA Journal, 2012, 50(3): 610-619 [96] Law CK. Combustion Physics. Cambridge: Cambridge University Press, 2006 [97] Wu K, Contino F, Yao W, et al. On the application of tabulated dynamic adaptive chemistry in ethylene-fueled supersonic combustion. Combustion and Flame, 2018, 197: 265-275 doi: 10.1016/j.combustflame.2018.08.012 [98] Pope SB. Ten questions concerning the large-eddy simulation of turbulent flows. New Journal of Physics, 2004, 6: 35-35 doi: 10.1088/1367-2630/6/1/035 [99] Yao W, Wu K, Fan XJ. Development of skeletal kerosene mechanisms and application to supersonic combustion. Energy & Fuels, 2018, 32(12): 12992-13003 -