Fluid Mechanics and Flight Mechanics

Internal flow field development process of a hypersonic vehicle during protective cover separation

  • Jun ZHONG ,
  • Xiaoqiang FAN ,
  • Bing XIONG ,
  • Lei CHEN ,
  • Xiao TANG
Expand
  • 1.Advanced Propulsion Technology Laboratory,National University of Defense Technology,Changsha 410073,China
    2.Hypervelocity Aerodynamics Institute,China Aerodynamics Research and Development Center,Mianyang 621000,China
    3.National Key Laboratory of Aerospace Physics in Fluids,Mianyang 621000,China
E-mail: xqfan@nudt.edu.cn

Received date: 2025-07-31

  Revised date: 2025-09-01

  Accepted date: 2025-12-01

  Online published: 2025-12-15

Supported by

National Natural Science Foundation of China(12372298)

Abstract

The“simultaneous separation”sequence, involving the concurrent unlocking of the booster and protective cover from an air-breathing hypersonic vehicle, facilitates axial separation by utilizing the pressurized gas filling of the internal flow path. However, during the initial separation phase under this sequence, complex and variable pressure oscillations arise within the vehicle’ s internal flow path due to the interaction of moving shock waves, shock trains, and gas filling. Beyond conventional collision risks, a potential overpressure risk from the gas filling process is introduced into this sequence. Numerical simulations of developing flow field within the vehicle’ s internal flow path during protective cover separation were carried out, using overset moving mesh technology and solving the unsteady Reynolds-Averaged Navier-Stokes (RANS) equations. The temporal flow field structures and unsteady pressure characteristics within the internal flow path were obtained. The evolution mechanism of the internal flow field during protective cover separation, as well as the influence mechanism between protective cover motion and stage distance variation on the flow field development during initial separation phase, were analyzed. The results indicate that during the initial separation phase under the“simultaneous separation”sequence, the filling and venting process of the internal flow path exhibits five distinct stages characterized by significantly different flow phenomena: gap-induced jet flow, moving shock sweep, shock train forward movement, gas backflow, and venting transition. The maximum pressure observed within the internal flow path during protective cover separation is primarily attributable to shock system pressurization, shock train pressurization, and gas filling pressurization/accumulation, rather than the pressure jump induced by the moving shock. The operational state of the internal flow path, whether started or unstarted, determines if the influence of cover motion and stage distance variation on the internal flow field manifests as a unidirectional dependency or a coupled interaction relationship.

Cite this article

Jun ZHONG , Xiaoqiang FAN , Bing XIONG , Lei CHEN , Xiao TANG . Internal flow field development process of a hypersonic vehicle during protective cover separation[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2026 , 47(8) : 132638 -132638 . DOI: 10.7527/S1000-6893.2025.32638

References

[1] WEN X, LIU J, LI J, et al. Design and numerical simulation of a clamshell-shaped inlet cover for air-breathing hypersonic vehicles[J]. Journal of Zhejiang University: Science A201920(5): 347-357.
[2] CHAMBERLAIN R. Time-accurate calculation of the HEDI shroud separation event[C]∥Annual Interceptor Technology Conference. Huntsville: AIAA, 1992.
[3] LI Y, REIMANN B, EGGERS T. Coupled simulation of CFD and flight mechanics with a two-species-gas-model for the hot staging of a multistage rocket[C]∥19th AIAA International Space Planes and Hypersonic Systems and Technologies Conference. Atlanta: AIAA, 2014.
[4] 蒋增辉, 宋威, 陈农, 等. 高超声速风洞子母弹大迎角抛壳投放试验[J]. 实验流体力学201630(5): 42-48.
  JIANG Z H, SONG W, CHEN N, et al. Hypersonic wind tunnel drop-model test on cover ejection from cargo projectile at large angle of attack[J]. Journal of Experiments in Fluid Mechanics201630(5): 42-48 (in Chinese).
[5] 赵飞, 刘丽玲, 石泳, 等. 类X-43A飞行器高超声速分离仿真[J]. 航空学报202243(5): 221-230.
  ZHAO F, LIU L L, SHI Y, et al. Hypersonic separation simulation of aerocraft similar to X-43A[J]. Acta Aeronautica et Astronautica Sinica202243(5): 221-230 (in Chinese).
[6] 唐伟, 刘深深, 余雷, 等. 用于级间分离研究的TBCC动力TSTO气动布局概念设计[J]. 空气动力学学报201937(5): 698-704, 721.
  TANG W, LIU S S, YU L, et al. Conceptual design of TBCC based TSTO configurations for stage seperation investigation[J]. Acta Aerodynamica Sinica201937(5): 698-704, 721 (in Chinese).
[7] 王粤, 汪运鹏, 王春, 等. 一种并联两级入轨飞行器纵向分离方案的数值研究[J]. 航空学报202344(11): 127634.
  WANG Y, WANG Y P, WANG C, et al. Numerical study of longitudinal stage separation for parallel-staged two-stage-to-orbit vehicle[J]. Acta Aeronautica et Astronautica Sinica202344(11): 127634 (in Chinese).
[8] 郭凤美, 余梦伦. 导弹分离设计技术研究[J]. 导弹与航天运载技术2014(1): 5-10.
  GUO F M, YU M L. Research on missile separation design techniques[J]. Missiles and Space Vehicles2014(1): 5-10 (in Chinese).
[9] BLOCKER W, RUEBUSH D. X-43A stage separation system-a flight data evaluation[C]∥AIAA/CIRA 13th International Space Planes and Hypersonics Systems and Technologies Conference. Capua: AIAA, 2005.
[10] 朱学昌, 李浩远, 喻天翔, 等. 低空高速飞行器整流罩分离技术研究现状和展望[J]. 固体火箭技术201437(1): 12-17.
  ZHU X C, LI H Y, YU T X, et al. Research status and prospects for low-altitude and high-speed fairing separation technique[J]. Journal of Solid Rocket Technology201437(1): 12-17 (in Chinese).
[11] 王振国, 梁剑寒, 丁猛, 等. 高超声速飞行器动力系统研究进展[J]. 力学进展200939(6): 716-739.
  WANG Z G, LIANG J H, DING M, et al. A review on hypersonic airbreathing propulsion system[J]. Advances in Mechanics200939(6): 716-739 (in Chinese).
[12] HOLLAND S D, WOODS W C, ENGELUND W C. Hyper-X research vehicle experimental aerodynamics test program overview[J]. Journal of Spacecraft and Rockets200138(6): 828-835.
[13] HAUDRICH D, BRASE L. Flutter and divergence assessment of the HyFly missile[C]∥50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference. California: AIAA, 2009.
[14] BOLENDER M A, DAUBY B, MUSE J A, et al. HIFiRE 6: overview and status update 2014[C]∥20th AIAA International Space Planes and Hypersonic Systems and Technologies Conference. Glasgow: AIAA, 2015.
[15] MARSHALL L, CORPENING G, SHERRILL R. A chief engineer’s view of the NASA X-43A scramjet flight test[C]∥AIAA/CIRA 13th International Space Planes and Hypersonics Systems and Technologies Conference. Capua: AIAA, 2005.
[16] FOELSCHE R, BECKEL S, BETTI A, et al. Flight results from a program to develop a freeflight atmospheric scramjet test technique[C]∥14th AIAA/AHI Space Planes and Hypersonic Systems and Technologies Conference. Canberra: AIAA, 2006.
[17] 董楠. 吸气式高超声速飞行器多体分离流动特性及机理的数值研究[D]. 武汉: 华中科技大学, 2022.
  DONG N. Numerical study on flow characteristics and mechanism of air-breathing hypersonic aircrafts with multi-body separation[D]. Wuhan: Huazhong University of Science and Technology, 2022 (in Chinese).
[18] 郭善广, 柳军, 金亮, 等. 高超飞行器内流道激波振荡问题的数值研究及试验验证[J]. 实验流体力学201226(1): 7-11.
  GUO S G, LIU J, JIN L, et al. Numerical simulation and experiment validation on shock oscillations of inner flow path of hypersonic vehicle[J]. Journal of Experiments in Fluid Mechanics201226(1): 7-11 (in Chinese).
[19] 邹东阳, 吴岸平, 林敬周. 前向抛罩分离安全判定方法[J]. 航空学报202546(12): 80-89.
  ZOU D Y, WU A P, LIN J Z. Safety judgment method of forward separation of protective shield[J]. Acta Aeronautica et Astronautica Sinica202546(12): 80-89 (in Chinese).
[20] 宋威, 艾邦成. 多体分离动力学研究进展[J]. 航空学报202243(9): 025950.
  SONG W, AI B C. Multibody separation dynamics: review[J]. Acta Aeronautica et Astronautica Sinica202243(9): 025950 (in Chinese).
[21] 闻讯, 柳军, 夏智勋. 吸气式高超声速飞行器助推分离过程数值仿真[J]. 国防科技大学学报201941(1): 34-40.
  WEN X, LIU J, XIA Z X. Numerical simulation of booster separation for an air-breathing hypersonic vehicle[J]. Journal of National University of Defense Technology201941(1): 34-40 (in Chinese).
[22] BUNING P G, WONG T C, DILLEY A D, et al. Computational fluid dynamics prediction of hyper-X stage separation aerodynamics[J]. Journal of Spacecraft and Rockets200138(6): 820-827.
[23] 庞川博, 向玉伟, 马兴普, 等. 高超声速导弹进气道整流罩分离气动特性研究[J]. 弹箭与制导学报202040(3): 123-128, 134.
  PANG C B, XIANG Y W, MA X P, et al. Research on aerodynamic characteristics of inlet fairing separation from a hypersonic missile[J]. Journal of Projectiles, Rockets, Missiles and Guidance202040(3): 123-128, 134 (in Chinese).
[24] 朱国祥, 王磊, 苑朝凯, 等. 进气道整流罩全尺度动态分离试验研究[J]. 实验流体力学201933(4): 45-51.
  ZHU G X, WANG L, YUAN C K, et al. The experimental investigation on full-scale dynamic separation for an inlet shroud[J]. Journal of Experiments in Fluid Mechanics201933(4): 45-51 (in Chinese).
[25] 钟俊, 林敬周, 解福田, 等. 高超声速大动压下整流罩分离测力风洞试验[J]. 实验流体力学202438(2): 98-106.
  ZHONG J, LIN J Z, XIE F T, et al. Wind tunnel force test of fairing separation in hypersonic and high dynamic pressure situation[J]. Journal of Experiments in Fluid Mechanics202438(2): 98-106 (in Chinese).
[26] 林敬周, 王雄, 钟俊, 等. 高马赫数多体分离试验技术研究与应用[J]. 推进技术202041(4): 925-933.
  LIN J Z, WANG X, ZHONG J, et al. Investigation and application of high Mach number multi-body separation test technique[J]. Journal of Propulsion Technology202041(4): 925-933 (in Chinese).
[27] LIEN J, BOSE D, MARTIN J. Automated sensitivity analysis of hyper-X (X-43A) separation simulation[C]∥AIAA Modeling and Simulation Technologies Conference and Exhibit. Providence: AIAA, 2004.
[28] 刘广, 江玉刚, 任智毅, 等. 整体式整流罩高速分离流固耦合仿真[J]. 战术导弹技术2018(3): 30-37.
  LIU G, JIANG Y G, REN Z Y, et al. Fluid-structure coupling simulation of integrated fairing high-speed separation[J]. Tactical Missile Technology2018(3): 30-37 (in Chinese).
[29] 白晓征, 刘君, 郭正, 等. 冲压发动机进气道压力振荡过程的数值研究[J]. 推进技术200829(5): 562-565.
  BAI X Z, LIU J, GUO Z, et al. Numerical simulation of pressure oscillation in ramjet inlet[J]. Journal of Propulsion Technology200829(5): 562-565 (in Chinese).
[30] 赵星宇, 王翼, 范晓樯, 等. 高速进气道抛罩过程内流场演化特性研究[J]. 推进技术202142(5): 970-979.
  ZHAO X Y, WANG Y, FAN X Q, et al. Internal flow field evolution characteristics for inlet cover separation of high speed inlet[J]. Journal of Propulsion Technology202142(5): 970-979 (in Chinese).
[31] WANG S Y, LI C, CHEN W. Numerical investigation on unsteady flows with an air-breathing hypersonic vehicle during its shroud separation[C]∥21st AIAA International Space Planes and Hypersonics Technologies Conference. Xiamen: AIAA, 2017.
[32] 邓艳丹, 黄生洪, 杨基明, 等. 一种X-51A相似飞行器模型的气动特性初探[J]. 空气动力学学报201331(3): 376-380, 387.
  DENG Y D, HUANG S H, YANG J M, et al. A preliminary investigation on aerodynamic characteristics of an X-51A-like aircraft model[J]. Acta Aerodynamica Sinica201331(3): 376-380, 387 (in Chinese).
[33] 刘雪松. X-51A高超声速飞行器三维重建及气动/隐身特性分析[D]. 南京: 南京航空航天大学, 2015.
  LIU X S. Three-dimensional reconstruction and analysis of aerodynamic and stealth characteristic of X-51A hypersonic vehicle[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2015 (in Chinese).
[34] BORG M P. Laminar instability and transition on the X-51A[D]. West Lafayette: Purdue University, 2009.
[35] MENTER F R. Two-equation eddy-viscosity turbulence models for engineering applications[J]. AIAA Journal199432(8): 1598-1605.
[36] JIAO X L, CHANG J T, WANG Z Q, et al. Numerical study on hypersonic nozzle-inlet starting characteristics in a shock tunnel[J]. Acta Astronautica2017130: 167-179.
[37] 陶渊. 高超声速进气道中激波边界层干扰现象研究[D]. 长沙: 国防科技大学, 2018.
  TAO Y. The study of the shock wave/boundary layer interactions in hypersonic inlet[D]. Changsha: National University of Defense Technology, 2018 (in Chinese).
[38] 王巍. 有相对运动的多体分离过程非定常数值算法研究及实验验证[D]. 长沙: 国防科学技术大学, 2008.
  WANG W. Numerical simulation technique research and experiment verification for unsteady multi-body flowfield involving relative movement[D]. Changsha: National University of Defense Technology, 2008 (in Chinese).
[39] HERRMANN C, KOSCHEL W. Experimental investigation of the internal compression inside a hypersonic intake[C]∥38th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit. Indianapolis: AIAA, 2002.
[40] REINARTZ B U, HERRMANN C D, BALLMANN J, et al. Aerodynamic performance analysis of a hypersonic inlet isolator using computation and experiment[J]. Journal of Propulsion and Power200319(5): 868-875.
[41] WAGNER J L, YUCEIL K B, VALDIVIA A, et al. Experimental investigation of unstart in an inlet/isolator model in Mach 5 flow[J]. AIAA Journal200947(6): 1528-1542.
[42] RONDEAU M C, JORTIS T R. X-51A scramjet demonstrator program: waverider ground and flight test[C]∥44th International SETP Southwest Flight Test Symposium. Ft Worth, TX: Society of Flight Test Engineers, 2013.
[43] 陶渊, 范晓樯, 刘俊林. 超声速连续风洞喷管启动过程分析[J]. 推进技术201536(1): 24-29.
  TAO Y, FAN X Q, LIU J L. Studies on starting process of a continuous supersonic wind tunnel nozzle[J]. Journal of Propulsion Technology201536(1): 24-29 (in Chinese).
[44] LIAN X, XU H, DUAN L, et al. Flow structure and parameter evaluation of conical convergent-divergent nozzle supersonic jet flows[J]. Physics of Fluids202335(6): 066109.
[45] 高周景明, 蒋凌峰, 朱佳宇, 等. 电子初始位置对高能电子空间及时间辐射特性的影响[J]. 光散射学报202335(1): 71-77.
  GAO Z J M, JIANG L F, ZHU J Y, et al. Influence of electron initial position on space and time radiation characteristics of high energy electrons[J]. The Journal of Light Scattering202335(1): 71-77 (in Chinese).
Outlines

/