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Investigation of pressure wave behaviors in the rotational speed effects on a pressure-exchange wave rotor

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Chinese Journal of Aeronautics 2022年第5期35卷 247-259页

作者： Shining CHAN Huoxing LIU Hang SONG Fengchao LI Chongwen JIANG Zhenxun GAO Aircraft&Propulsion Laboratory Ningbo Institute of TechnologyBeihang UniversityNingbo 315800China National Laboratory for Computational Fluid Dynamics School of Aeronautic Science and EngineeringBeihang UniversityBeijing 100083China Research Institute of Aero-Engine Beihang UniversityBeijing 100083China AVIC CAPDI Integration Equipment Co. Ltd.Beijing 102206China Aero Engine Academy of China Beijing 101300China

A wave rotor is suitable for compact and efficient pressure-exchange between gas *** work measured the circumferential pressure distribution of the rotor/stator interfaces and utilized a CFD method to simulate the unsteady pressure *** experimental and CFD results showed some slopes in the circumferential pressure distributions,and the slopes indicated the traces of specific unsteady pressure *** traces varied regularly if the rotational speed varied within a range from-11%to+11%off the baseline value,but they were seriously disturbed if the rotational speed varied by-45%from the baseline *** verified that a pressure wave in a wave rotor tended to keep its pressure ratio and propagation velocity unchanged if the rotational speed varied by a small extent,and that the pressure wave could not keep its propagation patterns if the rotational speed varied by a large *** of the pressure wave behaviors,the wave rotor demonstrated specific regulations of the rotational speed effects on its operational states.

关键词： Experimental test Pressure exchange Pressure measurement rotational speed Unsteady pressure wave Wave rotor

Influence of tool rotational speed on microstructure and sliding wear behavior of Cu/B_4C surface composite synthesized by friction stir processing

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Transactions of Nonferrous Metals Society of China 2015年第1期25卷 95-102页

作者： R.SATHISKUMAR I.DINAHARAN N.MURUGAN S.J.VIJAY Department of Mechanical Engineering Coimbatore Institute of Technology Department of Mechanical Engineering V V College of Engineering School of Mechanical Sciences Karunya University

An attempt was made to synthesize Cu/B4C surface composite using friction stir processing（FSP） and to analyze the influence of tool rotational speed on microstructure and sliding wear behavior of the composite. The tool rotational speed was varied from 800 to 1200 r/min in step of 200 r/min. The traverse speed, axial force, groove width and tool pin profile were kept constant. Optical microscopy and scanning electron microscopy were used to study the microstructure of the fabricated surface composites. The sliding wear behavior was evaluated using a pin-on-disc apparatus. The results indicate that the tool rotational speed significantly influences the area of the surface composite and the distribution of B4C particles. Higher rotational speed exhibits homogenous distribution of B4C particles, while lower rotational speed causes poor distribution of B4C particles in the surface composite. The effects of tool rotational speed on the grain size, microhardness, wear rate, worn surface and wear debris were reported.

关键词： surface composite friction stir processing rotational speed wear rate microstructure

Output speed and flow of double-acting double-stator multi-pumps and multi-motors

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第4期12卷 301-309页

作者： De-sheng WEN Zhi-li WANG Jun GAO Yong ZHANG Shi-jun LV Tetsuhiro TSUKIJI College of Mechanical Engineering Yanshan University Qinhuangdao 066004 China College of Engineering and Applied Science Sophia University Tokyo 102-8554 Japan

The primary focus of this study was to investigate a series of novel motors and pumps,based on a new type of structure called *** double-stator structure can be used as pump or motor just based on the application requirements.A certain amount of pumps or motors can be formed in one shell,and these sub-pumps or sub-motors can work alone or be combined without influence on each *** this kind of double-stator pump(motor) is called a multi-pump(multi-motor).Through the analysis of multifarious connection modes of the double-acting double-stator multi-pumps and multi-motors,the mathematical expressions of the output flow rate and the rotational speed are *** results indicate that a quantity of different flow rates can be provided by one fixed-displacement multi-pump under the condition of unalterable driven speed by ***,when supplied by settled input flow,without complex variable mechanism,the functions of double-speed,multiple-speed,and even differential connection can be obtained by employing the use of a double-stator *** novel hydraulic transmission is made of such a double-stator multi-pump and multi-motor,and has broad application prospects.

关键词： Multi-pumps Multi-motors Flow rate rotational speed Hydraulic transmission Differential motor

Establishment of the thermo-mechanical coupling model of axle box bearings with track irregularity excitation and analysis of its temperature characteristics

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Applied Mathematics and Mechanics(English Edition) 2024年第11期45卷 1965-1986页

作者： Min WANG Shaopu YANG Yongqiang LIU Yanhong CHEN Kai ZHANG State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China School of Traffic and Transportation Shijiazhuang Tiedao UniversityShijiazhuang050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang050043China CRRC Tangshan Co. Ltd.Tangshan063000Hebei ProvinceChina China Water Resources Beifang Investigation Designand Research Co.Ltd.Tianjin300222China

As an important component of the running gear of high-speed trains,axle box bearings can cause lubricating grease failure and damage to bearing components under continuous high-temperature operation,which will affect the normal operation of highspeed ***,bearing temperature is one of the key parameters to be monitored in the online monitoring system for *** on the thermal network method,this paper establishes a thermal network model for the axle box bearing,considering the radial thermal deformation of the double-row tapered roller bearing components caused by the oil film characteristics and the temperature variations of the lubricating grease.A thermo-mechanical coupling model for the grease-lubricated double-row tapered roller axle box bearing of high-speed trains with track irregularity excitation is *** correctness of the model is verified using the test bench data,and the temperature of the bearing at different rotational speeds,loads,fault sizes,and ambient temperatures are investigated.

关键词： axle box bearing thermal network method temperature rotational speed

Effect of a self-rotating oxygen lance system on mass transfer between slag and molten steel

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Journal of Iron and Steel Research International 2021年第2期28卷 152-159页

作者： Qi Gao Wei Wu Jian-guo Zhi Bo Zhang Xiang-chen Li Metallurgical Technology Research Department Central Iron and Steel Research InstituteBeijing 100081China Inner Mongolia Enterprise Key Laboratory of Rare Earth Steel Products Research and Development Baotou 014010Inner MongoliaChina Inner Mongolia Baotou Steel Union Co. Ltd.Baotou 014010Inner MongoliaChina

To improve the efficiency of the steelmaking process,a system of self-rotating lance was designed,and corresponding cold simulation mechanism was *** influence of the self-rotating lance on the mass transfer rate between slag and molten steel was investigated by comparing this novel system with the traditional oxygen *** results show that the self-rotating lance can stably rotate with a gas jet as the power *** mass transfer rate increases with an increase in the top and bottom blow flow rates and with a decline in the lance *** 13.7% of the top blow flow rate is converted to stirring energy,which is approximately twice that of the traditional oxygen lance,and the mass transfer rate can increase by over 30%.Furthermore,the impact energy can be concentrated at different depths of the molten bath by adjusting the rotational *** the same energy density,the mass transfer rate produced by the self-rotating lance is higher;however,the influence of the energy density on the mass transfer rate is low when the rotational speed is 30-50 r/min.

关键词： Self-rotating lance Reaction force rotational speed Mass transfer rate Impact energy

Unsteady Operation of New Type Turbofan Engine with Aerodynamic Torque Converter Reducing Front Fan speed

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Journal of Thermal Science 2005年第3期14卷 206-210页

作者： Toshiaki KANEMOTO Seita SEKI Kazunori IDENO Ahmed Mohamed GALAL Kyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 Japan ProfessorKyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 JapanKyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 JapanKyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 Japan

It is desired to increase the rotational speed of the core engine of the turbofan so as to get the best efficiency for the next leap of engine technology. The conventional mechanism in which the front fan is directly connected to the output shaft of a core engine, have a limit of increasing the spool speed, because the fan diameter is very large. The authors have proposed a new driving system in which the front fan is driven through the aerodynamic torque converter. The front fan can work at the best performance at slower speed while the core engine runs more efficiently at higher speed. Continuously, this paper discusses the response of the front fan in the unsteady operation of the core engine, accompanying with the internal flow. The system has the acceptable responsibility in the unsteady operation which is very important for the aircrafts.

关键词： turbofan engine front fan torque converter rotational speed

A High Revolution speed Noncontact Ultrasonic Motor Driven by a Non-Symmetrical Electrode

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Chinese Physics Letters 2005年第10期22卷 2598-2600页

作者：杨斌刘景全陈迪蔡炳初 National Key Laboratory of Nano/Micro Fabrication Technology Key Laboratory for Thin Films and Microfabrication of the Ministry of Education Institute of Micro and Nano Science and Technology Shanghai Jiaotong University Shanghai 200030

A noncontact ultrasonic motor based on a non-symmetrical electrode is proposed. This motor has the advantages of using a simple driving electrode and having a high revolution speed. The revolution speed of its three-blade rotor can reach 5100rpm under a driving voltage of 20 V. A method operated easily is proposed to measure the output torque,

关键词： rotational speed Electrodes output torque ultrasonic motors

Simulation of Temperature Distribution in Hot Filament Chemical Vapor Deposition Diamond Films Growth on Si C Seals

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Journal of Shanghai Jiaotong university(Science) 2016年第5期21卷 541-547页

作者：刘建锦王亮张建国沈彬孙方宏 School of Mechanical Engineering Shanghai Jiaotong University

In this study, the temperature and gas velocity distributions in hot filament chemical vapor deposition(HFCVD) diamond film growth on the end surfaces of seals are simulated by the finite volume method. The influence of filament diameter, filament separation and rotational speed of the substrates is considered. Firstly,the simulation model is established by simplifying operating conditions to simulate the temperature and gas velocity distributions. Thereafter, the deposition parameters are optimized as 0.6 mm filament diameter, 18 mm filament separation and 5 r/min rotational speed to get the uniform temperature distribution. Under the influence of the rotational speed, the difference between temperature gradients along the directions perpendicular to the filament and parallel to the filament becomes narrow, it is consistent with the actual condition, and the maximum temperature difference on the substrates decreases to 7.4?C. Furthermore, the effect of the rotational speed on the gas velocity distribution is studied. Finally, diamond films are deposited on the end surfaces of Si C seals with the optimized deposition parameters. The characterizations by scanning electron microscopy(SEM) and Raman spectroscopy exhibit a layer of homogeneous diamond films with fine-faceted crystals and uniform thickness. The results validate the simulation model.

关键词： finite volume method substrate temperature hot filament chemical vapor deposition(HFCVD) rotational speed velocity field distribution

Effect of centrifugal counter-gravity casting on solidification microstructure and mechanical properties of A357 aluminum alloy

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China Foundry 2014年第1期11卷 14-19页

作者： Li Xinlei Hao Qitang Miao Xiaochuan Fan Li State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi'an Chaoma Technology Company Limited

To investigate the influence of Centrifugal Counter-gravity Casting(C3) process on the solidification microstructure and mechanical properties of the casting, A357 aluminum alloy samples were produced by different process conditions under C3. The results show that C3 has better feeding capacity compared with the vacuum suction casting; and that the mechanical vibration and the convection of melts formed at the centrifugal rotation stage suppress the growth of dendrites, subsequently resulting in the refinement of grains and the improvement of mechanical properties, density and hardness. A finer grain and higher strength can be obtained in the A357 alloy by increasing centrifugal radius and rotational speed. However, casting defects will appear near the rotational axis and the mechanical properties will decrease once the rotational speed exceeds 150 r·min-1.

关键词： centrifugal counter-gravity casting vacuum suction casting rotational speed solidification feeding