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Luan Y.,Nanjing University of Aeronautics and Astronautics | Wang H.,Nanjing University of Aeronautics and Astronautics | Wang H.,The State Key Laboratory of Fluid Power Transmission and Control | Zhao D.,Nanjing University of Aeronautics and Astronautics | And 2 more authors.
Jiqiren/Robot | Year: 2015

To accurately control a hopping robot with combustion powered linear actuator (CPLA), factors that influence the hopping-driving performance of CPLA are analyzed. Firstly, dynamic model is set up according to the working process of CPLA, and performance parameters are obtained. Nextly, how the mole ratio of oxidizer (nitrous oxide N2O) to fuel (propane C3H8) and injection pressures of the two gas influence the output performance of CPLA are analyzed by experiments. Results show that the influence do exist, when the mole ratio is 9.91, the hopping height of CPLA reaches a maximum, and a 3.17 kg hopping mechanism can hop as high as 3.2 m. CPLA energy efficiency is 8.4% and hopping efficiency is 7.01%. The CPLA outputs a high average power, and is of a large power-mass ratio during the driving hopping process. ©, 2015, Chinese Academy of Sciences. All right reserved.

Xu J.,Zhejiang University of Technology | Zhou Z.-Y.,Zhejiang University of Technology | Piao Z.-Y.,Zhejiang University of Technology | Piao Z.-Y.,The State Key Laboratory of Fluid Power Transmission and Control
Frontiers of Mechanical Engineering | Year: 2016

The accumulated damage process of rolling contact fatigue (RCF) of plasma-sprayed coatings was investigated. The influences of surface roughness, loading condition, and stress cycle frequency on the accumulated damage status of the coatings were discussed. A ball-ondisc machine was employed to conduct RCF experiments. Acoustic emission (AE) technique was introduced to monitor the RCF process of the coatings. AE signal characteristics were investigated to reveal the accumulated damage process. Result showed that the polished coating would resist the asperity contact and remit accumulated damage. The RCF lifetime would then extend. Heavy load would aggravate the accumulated damage status and induce surface fracture. Wear became the main failure mode that reduced the RCF lifetime. Frequent stress cycle would aggravate the accumulated damage status and induce interface fracture. Fatigue then became the main failure mode that also reduced the RCF lifetime. © 2016 Higher Education Press and Springer-Verlag Berlin Heidelberg

Zheng J.,Zhejiang University | Zheng J.,High Pressure Equipment | Zheng J.,The State Key Laboratory of Fluid Power Transmission and Control | Zhou C.,Zhejiang University | And 9 more authors.
Taiyangneng Xuebao/Acta Energiae Solaris Sinica | Year: 2015

An apparatus for hydrogen embrittlement testing under high-pressure gaseous hydrogen has been developed in P.R. China based on the studies on design of high-pressure hydrogen container, axial force self-balance method for the load rod, load measurement in high-pressure hydrogen, sealing in high-pressure hydrogen and systems for the refueling of hydrogen, and gas leak detection and monitoring. Slow strain rate tensile test, fatigue test, fracture toughness test, and fatigue crack growth test can be conducted under ultrahigh-pressure (140 MPa) gaseous hydrogen. The developed equipment is useful for materials selection, life prediction, and investigation on mechanism of hydrogen embrittlement. ©, 2015, Science Press. All right reserved.

Chen H.,Fuzhou University | Chen H.,The State Key Laboratory of Fluid Power Transmission and Control | Du H.,Fuzhou University | Du H.,FUJIAN HAIYUAN
Applied Mechanics and Materials | Year: 2013

In order to improve the flow stability when wafer scans at high speed, immersion lithography with small flow-thickness is proposed for the high resolution lithography. By using the numerical methods, the immersion flow is investigated to analyze the behaviors of liquid flow. Based on the flow characteristics of typical structures with different liquid thickness and scanning speed, the liquid mean-velocity on account of thousand sample points in the exposure area are studied, and the appropriate parameters and method of effective renovation with small thickness are also given. © (2013) Trans Tech Publications, Switzerland.

Jiang H.-Y.,Harbin Institute of Technology | Jiang H.-Y.,The State Key Laboratory of Fluid Power Transmission and Control | Huo Y.-T.,Harbin Institute of Technology | Ren Y.-K.,Harbin Institute of Technology | And 3 more authors.
Harbin Gongye Daxue Xuebao/Journal of Harbin Institute of Technology | Year: 2011

To make up the deficiency of traditional ac electrohydrodynamics in explaining fluid flowing in opposite direction, a 3D point plane electrode system is devised to carry out microfluidic driving experiments, and the influence of electrochemistry and ac electro-thermal on microfluidic driving under low ac frequency has been analyzed. It is found that the flow direction under ac range of 10 Hz~3 MHz in the device is point to plane all the time, which is opposite to the prediction from theory of ac electro-osmotic (ACEO). The experiments verifies the leading role of electrochemical reaction under low ac frequency, and the result indicates that the leading influencing factor of the phenomenon of microfluidic under low ac frequency in point plane electrode system is electrochemistry.

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