• Progress in flight tests of hypersonic boundary layer transition

    Guohua Tu, Jianqiang Chen, Xianxu Yuan, Qingtao Yang, Maochang Duan, Qiang Yang, Yi Duan, Xi Chen, Bingbing Wan, Xinghao Xiang [2021，37(11): 1591-1611]
    Boundary layer transition (BLT) can cause a sharp rise in heat flux and skin friction, which can seriously affect the flight performance and safety of hypersonic flight vehicles. Therefore, the mechanism, prediction and control of transition have become important issues that must be dealt with for the development of advanced flight vehicles, and it is also a research hotspot of particular interest. . .

     

  • Reviews on mechanics of ultra-high-temperature materials

    Daining Fang · Weiguo Li · Tianbao Cheng · Zhaoliang Qu · Yanfei Chen · Ruzhuan Wang · Shigang Ai [2021，37(9): 1347-1371]
    The demand for ultra-high-temperature ceramic materials in a wide range of applications in aerospace, nuclear industry and national defense is becoming stronger, in which the materials for high-end equipment often face complex and diverse thermal environments during the service process. The mechanical properties of the materials under high-temperature environments have attracted increasing conside. . .

     

  • Tuning frictional properties of molecularly thin erucamide films through controlled self?assembling

    Youyu Di · Shuai Zhang · Xi?Qiao Feng · Qunyang Li [0，(): 1045-1053]
    Self-assembled films (SAFs) have been proposed to be a promising candidate for molecularly thin lubricants. However, the frictional performance of SAFs is sensitively dependent on their molecular structures that are susceptible to external environments. Taking erucamide, a fatty amide widely used as a macroscale slip additive, as an example, we demonstrate that SAFs can be readily formed on variou. . .

     

  • Influence of modeling approaches and structural parameters on impact resistance of the human porous cranium

    Qianqian Wu · Jian Xiong [2021，37(6): 913-931]
    Failure mechanism and impact resistance of a human porous cranium are studied in detail by means of theoretical and numerical methods. It is hypothesized that pore distribution of a cranium directly affects cranial energy absorption, and a stretched beam model and a real beam model are taken as the example for the verification. Meanwhile, for the purpose of comparison with numerical results, a the. . .

     

  • Internal field study of 21700 battery based on long-life embedded wireless temperature sensor

    Haihua Chen · XianfLe Yang · Na Li · Likun Hu · Shaoqi Wang · Lin Wang · Jiang Zhou · Wei-Li Song · Lei Sun · Tai-Song Pan · Hao-Sen Chen · Daining Fang [2021，37(6): 898-904]
    The safety of lithium-ion batteries is an essential concern where instant and accurate temperature sensing is critical. It is generally desired to put sensors inside batteries for instant sensing. However, the transmission of internal measurement outside batteries without interfering their normal state is a non-trivial task due to the harsh electrochemical environment, the particular packaging str. . .

     

  • Experimental and numerical investigations into flow features in an intake duct for the waterjet propulsion under mooring conditions

    Renfang Huang · Ruizhi Zhang · Yiwei Wang · Xianwu Luo · Lei Zhu [2021，37(5): 825-842]
    The waterjet propulsion is widely applied in the marine vessels over 30 knots, and the intake duct is considered as an essential component that strongly relates to the propulsion performance. This paper sheds light on the flow features inside an intake duct under mooring conditions by using the particle image velocimetry (PIV) technique with three-dimensional (3D) numerical simulations. The hydrau. . .

     

  • Active feedback control of sound radiation in elastic wave metamaterials immersed in water with fluid–solid coupling

    Zhi-Hua He · Yi-Ze Wang · Yue-Sheng Wang [2021，37(5): 802-824]
    Due to their potential properties unlike traditional materials and structures, elastic wave metamaterials have received significant interests in recent years. With the coupling between the acoustic and vibration, their mechanical characteristics can be tuned by the active feedback control system at low frequency ranges in which the traditional passive control is limited. This work illustrates that. . .

     

  • Solvent-aided phase separation in hydrogel towards significantly enhanced mechanoresponsive strength

    Haibao Lu · Ziyu Xing · Mingji Chen · Kai Yu · Yong Qing Fu [2021，37(5): 756-765]
    Understanding working principles and thermodynamics behind phase separations, which have significant influences on condensed molecular structures and their performances, can inspire to design and fabricate anomalously and desirably mechanoresponsive hydrogels. However, a combination of techniques from physicochemistry and mechanics has yet been established for the phase separation in hydrogels. In. . .

     

  • PREFACE: Mechanics of Soft Materials and Flexible Structures

    Haibao Lu · Shaoxing Qu · Xiqiao Feng [2021，37(5): 745-746]
    Soft materials and lexible structures have become essential and hot topic, which is expected to signiicantly promote the research and development of current mechanics, physics, chemistry and life science. Furthermore, the soft materials and lexible structures have attracted enthusiastic attentions due to their great potential and practical applications in deployable structures, morphing structures. . .

     

  • Effect of Atwood number on convergent Richtmyer-Meshkov instability

    Jinggang Tang, Fu Zhang, Xisheng Luo, Zhigang Zhai [2021，37(3): 434-446]
    Developments of two-dimensional single-mode light/heavy interfaces driven by convergent shock waves are numerically investigated, focusing on the effect of the Atwood number on the Rayleigh-Taylor stabilization, the compressibility and the nonlinearity. Five different test gases, including CO2, Kr, R22, R12 and SF6, are considered with air as the ambient gas. It is clarified for the first time tha. . .

     

  • Experimental study on the origin of lobe-cleft structures in a sand storm

    Lin-Sen Zhang, Jian-Jun Tao, Guo-Hua Wang, Xiao-Jing Zheng [2021，37(1): 47-52]
    Lobes and clefts are characteristic structures at the front of sand storms. In this paper, their original formation mechanism and geometric features are studied experimentally and theoretically. A rotatable lock-exchange tank is utilized to avoid the strong local disturbances existing in the conventional horizontal apparatus, and the original lobe size is selected as the dominant spanwise waveleng. . .

     

  • Thinning air-water films stabilized by bacterial particles

    Song Wu, Yuehua Yang, Hongyuan Jiang [2021，37(1): 27-34]
    The ability of particles to stabilize liquid films has broad applications in many fields, such as drug delivery, biofuel catalysis, and crude-oil separation. The mechanism of particles to stabilize emulsions has been widely studied. However, how particles affect the stability of suspension films is still unclear. Here, the dynamics of bacterial particles on free liquid films during evaporation is . . .

     

  • Noise reduction for temperature-sensitive paint measurement contaminated by strong background radiation in a high enthalpy hypersonic tunnel

    Di Peng, Xu Liu, Lingrui Jiao, Ziyan Li, Xin Wen, Chaokai Yuan, Guilai Han, Yunfeng Liu, Yingzheng Liu, Zonglin Jiang [2021，37(1): 20-26]
    The strong background radiation in high enthalpy hypersonic shock tunnels has posed severe challenges for measurement using luminescent coatings. We proposed a solution for reducing background radiation from time-resolved temperature-sensitive paint (TSP) measure-ment in a hypersonic flow with Ma = 6.5 and T0 = 3525 K. The TSP was applied on an inlet ramp model, and the images were taken by a high. . .

     

  • How does the rarefaction of the air affect hypersonic vehicles

    Youda Ye [2021，37(1): 18-19]
    The scope, physical concept, and mathematical model for describing how the rarefaction of the air affects on hypersonic flows have been discussed. A new method, namely the data improved Naive–Stroke (DiNS) model, was proposed for the computation of hypersonic shear flows around vehicles flying at altitude of 30–100 km. Validation of the new continuum method has also been done.

     

  • Rarefied gas effect in hypersonic shear flows

    J. Chen, H. Zhou [2021，37(1): 2-17]
    Recently, as aerodynamics was applied to flying vehicles with very high speed and flying at high altitude, the numerical simulation based on the Navier-Stokes (NS) equations was found that cannot correctly predict certain aero-thermo-dynamic properties in a certain range of velocity and altitude while the Knudsen number indicates that the flow is still in the continuum regime. As first noted by Zh. . .