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China Aerospace Publishing House Co., LTD

Founded in 2016, bimonthly


CN 10-1384/O3

ISSN 2096-1642

Selected ArticlesMore+

Issue on Shock Waves and Complex Flows
Eccentric Effect on Evolution of Shock-Accelerated Double-Layer Gas Cylinder
FENG Li-li, ZHAI Zhi-gang, SI Ting, LUO Xi-sheng
2022, 7(2): 13-25.   doi: 10.19527/j.cnki.2096-1642.0959
367 HTML 132 (132)
Evolution of a double-layer gas cylinder induced by a planar shock wave was investigated experimentally and numerically. Three double-layer gas cylinders were generated based on the soap film technology. By fixing the radii of the inner and outer gas cylinders, and changing the position of the inner gas cylinder in the stream-wise direction, the eccentric effect on the double-layer gas cylinder evolution has been highlighted. The results show that when the inner gas cylinder is positioned upstream, a 'jet' toward the upstream interface of the outer cylinder is generated at the late stage. When the inner gas cylinder is positioned downstream, the coupling effect between two downstream interfaces occurs earlier. The linear velocities of the upstream interfaces of the inner and outer gas cylinders are obtained. It is found that the pressures inhibit and promote the upstream interfaces of the inner and outer gas cylinders respectively, and the pressure magnitude is closely related to the position of the inner cylinder. The rarefaction wave impact changes the movement behaviour of the upstream interface of the outer cylinder, and the linear phase will be prolonged or shortened. The outer gas cylinder width is promoted when the eccentricity exists, and its height gradually decreases as the inner one approaches downstream initially. When the inner gas cylinder is positioned upstream, the inner cylinder width is inhibited but its height changes little. The interfacial area and mean volume fraction of the double-layer gas cylinder were extracted from computations, and the results show that the mixing between gases will be promoted when the inner gas cylinder is positioned upstream. Finally, the time-variation of the circulation is obtained. It is found that the circulation of the double-layer gas cylinder at the early stage can be well predicted by the linear superposition of the existing models.
Issue on Shock Waves and Complex Flows
Suppression on Shock Oscillation of Impinging Jet
LI Xiang-ru, LIU Nian-hua, LIU Lu-han, HE Feng
2022, 7(2): 26-31.   doi: 10.19527/j.cnki.2096-1642.0898
383 HTML 152 (152)
Underexpanded impinging jets have complex shock structures and generate high-amplitude tones with discrete frequencies. Based on the schlieren images obtained by the high-speed camera and the results of noise measurements, the oscillations of shocks, the modes of instability waves in the jet shear layer and the generation of the discrete tones of underexpanded impinging jets were studied. In this paper, the experimental results of the impinging jet with an impact distance of 5 nozzle exit diameters were presented. It is found that there are two modes of the instability waves in the shear layer: symmetric and asymmetric modes. The sound source of the impinging tones at different modes is located at the instability flow structures after impinging on the plate. The feedback acoustic waves excite the shear layer at the nozzle lip and maintain the development of the instability waves. The oscillations of shocks are caused by the interactions between the shocks and the shear layer and are related to the characteristics of the instability modes. By weakening the disturbances of the feedback acoustic waves on the shear layer at the nozzle lip, the discrete tones are eliminated and the shock oscillations are suppressed.
Complex Dredging Thermal Protection Structure for Leading Edge
AI Bang-cheng, CHEN Si-yuan, HAN Hai-tao, HU Long-fei, CHU Min, QU Wei, YU Ji-jun
2019, 4(1): 1-7.   doi: 10.19527/j.cnki.2096-1642.0734
307 (39)
Based on dredging thermal protection method, an integrated leading edge structure was proposed to accommodate the severe heat flux and high heat flux gradient at the stagnation point. Considering the heat and force loadings, a thin shell structure with internal working medium was designed. Under thermal heating conditions, phase change and circulation of the working medium were established to achieve rapid heating transportation for the stagnation zone. The structure was integrated and then charged with working medium, and finally verified in flight test. The results showed that it started at about 94.5 s, and the thermal dredging efficiency achieved 23.4%.
Starting Process of a Double-Throat Ludwieg Tube Tunnel and the Extension of Its Effective Running Time
LI Chuang-Chuang, LI Zhi-yuan, ZHANG Zhen-hui, Wu Jie
 doi: 10.19527/j.cnki.20961642.1071
0 0
The Ludwieg tube wind tunnel serves as a crucial testing ground for fundamental studies of hypersonic aerodynamics. However, the quick-opening valve-started hypersonic Ludwieg tube wind tunnel has been affected by the quickopening valve for a long time, resulting in different types of flow disturbance modes. The double-throat aerodynamic configuration can effectively eliminate the disturbance source of the upstream components of the quick-opening valve-started hypersonic Ludwieg tube wind tunnel, but it will lead to a significant reduction in the effective running time of the wind tunnel. In order to solve this problem, the unsteady numerical simulation was used to study the start-up characteristics of the hypersonic Ludwieg tube wind tunnel with double-throat aerodynamic configuration. Then, a fusion design was carried out for the first nozzle expansion section and the stable section. The effects of different combinations of expansion angles and stable sections on the start-up time and flow field quality of the wind tunnel were studied. The results show that the effective running time of the hypersonic Ludwieg tube wind tunnel with double-throat aerodynamic configuration can be increased by nearly 20% by using the combined design of reducing the expansion angle, and the static flow field quality in the downstream experimental section is almost unaffected, which effectively improves the experimental ability of the wind tunnel. At the same time, compared with the larger expansion angle combination, the smaller expansion angle design can reduce the total pressure loss by about 10%.
Parameter Optimization of Jet Control for Compression Ramps of Two-Dimensional Inlet Based on Isight
SUN Feng-tao, SHI Zhi-wei, ZHANG Wei-lin, DING Bao-zheng, SHU Yan-lin
 doi: 10.19527/j.cnki.2096-1642.1080
33 2

Two-dimensional inlet is usually used in the wide-speed-range aircraft which has a higher flying velocity region. It is difficult to meet more requirements under both low-speed and high-speed flow conditions. Although the inlet performance could be improved by using jets to control shock waves on compression ramps, the existing jet excitation only push the shock wave toward the cowl, which may not achieve optimal performance. The optimization of jet control parameters is a significant problem. The effects of different optimization variables on inlet performance were investigated at Ma=6 based on Isight with the Hooke-Jeeves method, in which different jet parameters were selected as optimization variables, flow coefficient was selected as constraint condition and maximum total pressure recovery coefficient was selected as objective function for optimization. The result show that the Hooke-Jeeves method is able to optimize inlet with jet control. The optimized inlet can meet the requirements of flow coefficients. The total pressure recovery coefficient after optimizing the jet angle is increased by 18% compared to the inlet without jet, and the total pressure recovery coefficient after combination optimization is increased by 2.82% compared to only optimizing the jet angle.

Aerodynamic Calculation of Airfoil Dynamic Stall Based on Data-Driven Transition Model
LI Jin-ying, DAI Yu-ting, YANG Chao
 doi: 10.19527/j.cnki.2096-1642.1069
18 1
The laminar flow separation and separation-induced transition at low Reynolds number are complex, and have great difficulty in numerical simulation. Based on fully-connected back-propagation neural network, a data-driven model of intermittency at low Reynolds number was established. The input parameters of the data-driven model to reflect transition process and predict intermittency were selected through optimization design. By modifying the k-ω SST two equation turbulence model with a data-driven transition equation, the flow field evolution and unsteady aerodynamic characteristics of a two-dimensional airfoil under dynamic stall were solved. Results show that the data-driven transition equation combined with two equation turbulence model has the generalization ability for the angle of attack, and clearly reflects the typical flow conditions such as the growth and shedding of the leading-edge vortex and the reattachment of the flow under dynamic stall. The relative error of unsteady aerodynamic lift in dynamic stall between the data-driven transition model and the SST-γ three equation model is lower than 12%.
Flutter Regularity of Flying Wing Configuration with All-Moving Wing Tip
WANG Wei-ji, QIAN Wei, HE Xiang, AI Xin-yu, CHEN Zheng
 doi: 10.19527/j.cnki.2096-1642.1085
23 5
The performance requirements of modern fighters meet multiple targets such as high speed, high mobility, stealth, lightweight and so on. The aircraft with a tailless flying wing configuration has the advantages of high aerodynamic efficiency, good mobility, low detectability, and flying integration. Such configuration adopts a structural design with wing and body fusion, multi-control surface and all-moving wing tip. The innovative structure of the wing tip highlights its aero- elasticity problem, in which the coupling effect between the structure of wing tip and the control surface makes the flutter behavior particularly prominent. This paper adopted the linear flutter method and the mode tracking method to study the flutter problem of all-moving wing tip. According to the study, the flutter coupling has three types for the aircraft with a tailless flying wing configuration:coupling between the first symmetrical bending of wing and the symmetric rotation of all-moving wing tip (symmetrical couple), coupling between the first anti-symmetrical bending of wing and the anti-symmetric rotation of all-moving wing tip (antisymmetric couple) and the fuselage mode in flutter. It is found that the flutter speed of the anti-symmetric coupling type is lower than that of the symmetric coupling type. From the flutter result, the coupling flutter speed of the fuselage and wing is higher than that of the former two, and the coupling speed of the fuselage and the all-moving wing tip is lower than that of the former two. The main structural factors affecting the symmetric coupled flutter are wing bending stiffness and rotational stiffness of the all-moving tip, while the main structural factors affecting the antisymmetric coupled flutter are wing bending stiffness, fuselage rotational inertia and rotational stiffness of the all-moving tip. The all-moving wing tip structure is the internal factor that makes the tailless flying wing prone to flutter.
Prediction of Hypersonic Boundary Layer Transition on Ablative Rough Surfaces of Deep Space Reentry Capsules
LI Qi, ZHAO Rui, CHEN Zhi, GUO Bin, WANG Qiang
 doi: 10.19527/j.cnki.2096-1642.1073
16 0
In order to improve aerodynamic deceleration efficiency, deep space reentry capsules generally adopt large blunt windward shape and ablative heat protection system. However, factors such as the flat forebody shape and the sharp increase in surface roughness caused by aerothermodynamic heating and ablation easily lead to the instability of the windward flow- field of the capsule, resulting in the transition or even evolution into turbulence, which greatly changes the distribution of the surface heat flux and brings great challenges to the safety of the capsule. Formerly the studies on the instability mecha- nism and simulation for the transition of hypersonic boundary layer under the change of microscopic morphology of large blunt heat shield are relatively unexplored. Using the γ-Reθ transition model and k-ω-γ transition model based on hypersonic and rough element correction, the intermittent factors of rough element equivalent roughness height, incoming Reynolds number, angle of attack and chemical non-equilibrium basic flow on the windward surface of the large blunt heat shield were analyzed. The development law of hypersonic boundary layer transition and aerothermodynamic effect on ablative rough sur- faces of deep space reentry capsules were studied.
Research on Aerothermoelasticity for Hypersonic Inlet with Complex Internal Flow
YE Kun, ZHAN Xu, ZHANG Yi-fan, YE Zheng-yin
 doi: 10.19527/j.cnki.2096-1642.1053
44 4
Hypersonic inlet is very easy to induce aerothermoelastic problems under the aerodynamic load and aero-thermal action of complex flow. Deeply understanding the aerothermoelasticity mechanism of complex internal flow is of great significance for the detailed design of hypersonic inlet in the future. In this paper, a static/dynamic aerothermoelastic analysis framework was established, and the mechanism of the influence of static/dynamic aerothermoelasticity on the flow field structure and performance of three-dimensional hypersonic inlet was studied in depth. The results of static aerothermoelastic analysis show that the aerothermoelastic deformation obtained by the two-way coupling method is relatively large, and the deformation of the leading edge of the inlet lip is the largest. The structural deformation changes the shock wave structure near the lip edge, enhances the shock wave intensity inside the inlet, increases the length of the separation zone and the temperature of the outer wall, and changes the flow field at the outlet. At the same time, the aerothermoelastic deformation will lead to the increase of mass flow coefficient and pressure rise ratio, and reduce the total pressure recovery coefficient. The results of dynamic aerothermoelastic analysis show that the displacement response of the structure converges when the aerodynamic heating is not taken into account. After considering aerodynamic heating, the structural displacement response presents a limit cycle trend. Aerodynamic heating may change the dynamic response characteristics of the inlet structure. Because the structural frequencies of the intake ports are very close to each other, "beat" phenomenon exists in the dynamic response of the structure. The leading edge deformation is large and the amplitude is small, while the trailing edge deformation is small and the amplitude is large. The structure vibration leads to significant dynamic changes in the flow field structure and significant fluctuations in the performance parameters, especially for the pressure rise ratio at the outlet. It is hoped that the research in this paper will deepen the understanding of the aerothermoelasticity in the complex flow structure of the inlet, in order to provide reference for the detailed design of the inlet in the future.
Experiment for Heat Transport and Flow Structure of a Two-Layer Thermal Convection
WANG Mu, CHEN Yang, WANG Wei, WEI Ping
 doi: 10.19527/j.cnki.2096-1642.1066
28 3
Two-layer thermal convection exists widely in nature. In the present work, an experiment was conducted to inves- tigate the heat transport and flow structure in two-layer thermal convection. In a rectangular convection cell, two immiscible fluids, glycerol and 2 cs silicone oil, were used as the working fluids. In the lower-thin glycerol layer, the bottom boundary was subjected to a no-slip boundary condition (BC), and the interface was subjected to slip BC. The aspect ratio of glycerol layer (lower) was Γ1=10.4. The Rayleigh number and Prandtl number of the glycerol layer covered the ranges of 260 ≤ Ra1 ≤ 6 000 and 3 708<Pr1<7 000, respectively. In the upper-thick silicone oil layer, the boundary at the top was subjected to no-slip BC. The aspect ratio of silicone oil (upper) was Γ2=0.53. The Rayleigh number and Prandtl number of the silicone oil layer covered the ranges of 1.5×109Ra2 ≤ 2.0×1010 and 28<Pr2 <33. It is found that the two-layer thermal convection has different heat transfer efficiencies and flow structures in two regions. For region 1 where the heat flux is smaller than a certain value, the glycerol layer (lower) is in a stable stratified state. For region 2 where the heat flux is greater than the certain value, a cellular pattern was formed in glycerol layer and the global heat transport was sharply increased through a subcritical bifurcation. The heat transport of glycerol layer exhibits oscillatory instability at the critical Rayleigh number Ra1c=1 523, which is smaller than the theoretic value 1 708 of critical value Ra for the 2D infinite Rayleigh-Bénard convection (RBC) with both rigid BCs. It reveals that the slip BC makes the fluid become unstable easier and enhances the heat transport. A measurement with shadowgraph method was further conducted. The cellular pattern of glycerol layer, the interface and hot plumes were also studied.
Experiment on Shock Wave Control of a Hypersonic Vehicle Standard Model Based on Plasma Synthetic Jet
XIE Wei, HU Guo-tun, SHI Wei, ZHOU Yan, LU Hong-bo, LUO Zhen-bing
 doi: 10.19527/j.cnki.2096-1642.1065
40 4
The novel active flow control technology based on plasma synthetic jet (PSJ) has great application potential in the field of shock wave control due to its advantages such as no gas source, strong control ability and wide excitation frequency band. The control effect of single-pulsed PSJ on head bow shock and wing shock of a hypersonic vehicle model and the drag reduction effect were experimentally studied in a hypersonic wind tunnel. The results show that the opposing PSJ can significantly increase the standoff distance of the head bow shock, and the transverse PSJ can basically eliminate the wing shock completely. The maximum instantaneous drag reduction rate of the vehicle measured by the dynamic force sensor is about 15.5%, but the drag change measured by the sensor has a delay of about 250 μs. The influence of discharge energy, incoming flow total pressure, exit diameter and cavity volume on the control effect of the head bow shock was also studied.
Cover and contents of Vol.8 No.5
2023, 8(5): .  
30 12
Issue on Theory and Application of Advanced Engines
Dynamic Response Characteristics of Oblique Detonation Waves in Non-Uniform Inflows
TENG Hong-hui, NIU Shu-zhen, YANG Peng-fei, ZHOU Lin, WANG Kuan-liang
2023, 8(5): 1-9.   doi: 10.19527/j.cnki.2096-1642.1033
58 HTML 10 18
Issue on Theory and Application of Advanced Engines
Effects of Inlet Condition Variations on the Operating Modes of Rotating Detonation Engines
YAO Song-bai, TANG Xin-meng, ZHANG Wen-wu
2023, 8(5): 10-18.   doi: 10.19527/j.cnki.2096-1642.1041
76 HTML 12 16
Issue on Theory and Application of Advanced Engines
Influence of Bypass Location on Two-Dimensional Shock Vectoring Nozzle
SHU Bo-wen, HUANG Jiang-tao, GAO Zheng-hong, HE Cheng-jun, XIA Lu
2023, 8(5): 19-27.   doi: 10.19527/j.cnki.2096-1642.1055
35 HTML 5 4
Issue on Theory and Application of Advanced Engines
Mechanism Analysis of Start and Unstart Flow Characteristic Structures of a Supersonic Inlet
CHEN Ya-qian, HU Ke-qi, WANG Gao-feng
2023, 8(5): 28-37.   doi: 10.19527/j.cnki.2096-1642.1047
48 HTML 7 10
Issue on Theory and Application of Advanced Engines
Unsteady Flow Driven by the Counter-Flow Jets of High-Altitude Engine Based on DSMC Simulation
WU Jun-lin, LI Zhong-hua, PENG Ao-ping, LI Lang-quan, LIANG Jie
2023, 8(5): 38-45.   doi: 10.19527/j.cnki.2096-1642.1059
57 HTML 8 12
Research Paper
Numerical Simulation on the Scalar Transport in Rotating Channel Turbulence
ZHANG Yi-ning, CHEN Yang, CAI Qing-dong, YANG Yan-tao
2023, 8(5): 46-53.   doi: 10.19527/j.cnki.2096-1642.1048
33 HTML 6 6
Research Paper
Research on Aerodynamic Performance of High-Pressure Capturing Wing with Bi-Wing Configuration in Wide-Speed Range
XIAO Yao, CUI Kai, LI Guang-li, TIAN Zhong-wei, CHANG Si-yuan
2023, 8(5): 54-60.   doi: 10.19527/j.cnki.2096-1642.1049
59 HTML 13 8