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Xiangyang Liu,Jimin Xu,Tianwang Lai,Maogang He Techno-Press 2023 Advances in nano research Vol.15 No.3
In order to develop better method to enhance and control the flow and heat transfer inside the radiator of electronic device, the synergistic effect of MHD nanofluids and porous medium on the flow and heat transfer in rectangular opened channel is simulated using Lattice Boltzmann method. Three nanofluids of CuO-water, Al<sub>2</sub>O<sub>3</sub>-water and Fe<sub>3</sub>O<sub>4</sub>-water are studied to analyze the influence of the type of nanofluid on the synergistic effect. The simulation results show that the porous medium can increase the flow velocity in fluid zone adjacent to the porous medium and enhance the heat transfer on the surface of the channel. Under no magnetic field, when the porosity of porous medium is 0.8, the Nusselt number is 4.46% higher than when the porosity is 0.9. Al<sub>2</sub>O<sub>3</sub>-water has the best heat transfer effect among the three nanofluids. At Ф=0.06, Ha=100, θ=90°, ε=0.9, Nu of Al<sub>2</sub>O<sub>3</sub>-water is 6.51% larger than that of CuO-water and 5.05% larger than that of Fe<sub>3</sub>O<sub>4</sub>-water. Magnetic field enhances seepage in porous medium and inhibits heat transfer in the bottom wall. When Ha=30 and 60, the inhibiting effect is the most significant as the magnetic field angle is 90°. And when Ha=100, the inhibiting effect is the most significant as the magnetic field angle is 120°.
Qiang Liu,Zhaohui Meng,Ronghui Wu,Liyun Ma,Wu Qiu,Honghao Zhang,Shuihong Zhu,Lingqing Kong,Zijjie Xu,Aniruddha Patil,Xiangyang Liu 한국섬유공학회 2019 Fibers and polymers Vol.20 No.10
In this work, regenerated silk fibroin (RSF) and silicon dioxide (SiO2) composite fiber was successfully extrudedby wet spinning method. The effect of SiO2 addition on structure of the composite fiber at microscopic level is studied, whichsubsequently correlated to the mechanical performance. The best concentration ratio for composite fiber is identified byscreening SiO2 concentration from 0.025 w/w% to 0.5 w/w%. The experimental results revealed that the SiO2 at a lowconcentration of 0.1 w/w% was well distributed. The breaking stress, breaking strain and Young’s modulus at 0.1 w/w% SiO2addition of the RSF fibers increased considerably compared to the neat RSF fibers from 243±3 to 458±21 MPa, 51±4 % to54±7 % and 6.34±0.55 to 11.69±1.12 GPa, respectively. To the best of our knowledge, this is the first report for RSF/SiO2composite fiber. We believed the insight provided in this report which looks into the structural evolution should be beneficialto the future design and building of other advanced functional fibers.
Tianyan Liu,Xiangyang Xu,Minghui Zhang,Runbo Zhang,Yue Wu,Hongzhi Ji,Yanfang Liu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.7
Under the engaging process, excessive temperature of clutch plates may lead to thermal failure. Existing research has failed to find the hot spot and the radial temperature difference real-timely. They also neglected the influence of dynamic sliding process and hydraulic characteristics. Thus, a multi-domain dynamic model of the whole clutch was proposed, involving the mechanical dynamics, the hydraulic dynamics and thermics. With the thermal resistance network method, the real-time axial and radial temperature prediction of clutch plates was realized. The highest temperature occurs on the friction pairs of axial middle and the maximum value occurs on the radial 5th mass. Compared with the results by FEM, the deviation is about 6.5 %, but the time duration is reduced significantly. Furthermore, the influence of the outer hub vibration (160 Hz, 0.2 Hz) on the dynamic characteristics was discussed. This work was tested to be an effective and good basis for the health prediction of wet clutches.
Xiangyang Xu,Xupeng Fan,Peng Diao,Huaiju Liu 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.7
A new gear tooth modification model of planetary gear system was established by considering the characteristics of tooth longitudinal crowning modification and tooth profile modification. Using this model, the influences of modification parameters on the time-varying mesh stiffness, transmission error, contact spots and dynamic response of the planetary gear system were analyzed through numerical analysis. The results show that tooth profile modification can effectively restrain the mesh stiffness sudden variation in the single and double tooth alternation of both the internal and external mesh pairs, and significantly decrease the transmission error fluctuation. However, longitudinal crowning modification has no marked influence on mesh stiffness sudden variation or transmission error fluctuation. The tooth profile modification can significantly reduce the sudden variation of tooth surface load during gear mesh course. Longitudinal crowning modification can make the tooth surface load evenly distributed in tooth width direction. When the external meshing pairs are modified at the tooth profile individually, the magnitude values of main response resonance peaks of internal meshing pairs have a great reduction, but those values of external meshing pairs change slightly. In the case of tooth profile modification of the internal meshing pairs, the phenomenon is reversed. By contrast with tooth profile modification, longitudinal crowning modification has little influence on the resonance peaks of internal and external meshing pairs.
Leipo Liu,Xiangyang Cao,Zhumu Fu,Shuzhong Song,Hao Xing 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.2
This paper is concerned with the input-output finite-time control of uncertain positive impulsive switched systems(UPISS) with time-varying and distributed delays. Firstly, the definition of input-output finite-time stability is extended to UPISS, and the proof of the positivity of UPISS is also given. Then, by constructing multiple linear copositive Lyapunov functions and using the mode-dependent average dwell time(MDADT) approach, a state feedback controller is designed, and sufficient conditions are derived to guarantee that the corresponding closedloop system is input-output finite-time stable(IO-FTS). Such conditions can be easily solved by linear programming. Finally, two examples are given to demonstrate the effectiveness of the proposed method.
Shulai Liu,Xiangyang Li,Xuxia Zhou,Xilin Zhang,Yuting Ding 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.5
Differences between ordinary and dark muscleof skipjack tuna (Katsuwonus pelamis) including proximatecomposition, flavor, color, texture, and freshness wereinvestigated. Ordinary muscle had a higher crude proteincontent, but a lower crude lipid content than dark muscle. Alcohols (30.41%) and aldehydes (25.56%) were theprominent flavor compounds present in ordinary muscle,whereas hydrocarbons (39.51%) and ketones (21.81%)were more abundant in dark muscle. Different L*, a*, andb* values were also observed. Texture profile analysis(TPA) showed that dark muscle had higher values foradhesiveness, and lower values for cohensiveness, chewiness,and resilience. After mechanical breaking, large myofibrilfragments were observed in ordinary muscle under phasecontrast microscopy, but not in dark muscle. Freshnessindices, including K values, total volatile basic nitrogen(TVB-N), and thiobarbituric acid (TBA) values of darkmuscle were higher than for ordinary muscle.