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2018 2

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X射线阻射性 1

三流体喷嘴喷雾干燥技术 1

多功能团簇体填料 1

抗菌性能 1

机械性能 1

齿科复合树脂 1

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Piezoelectric diffuser/nozzle micropump with double pump chambers

WANG Wei, ZHANG Ying, TIAN Li, CHEN Xiaojie, LIU Xiaowei

《机械工程前沿（英文）》 2008年第3卷第4期页码 449-453 doi: 10.1007/s11465-008-0076-4

摘要： To eliminate check valve fatigue and valve clogging, diffuser/nozzle elements are used for flow rectification in a valveless diffuser/nozzle micropump instead of valves. However, the application of this type of micropump is restricted because of its pulsating or periodic flow and low pump flux. In this paper, a diffuser/nozzle Si/Glass micropump with two pump chambers by IC and MEMS technology is designed. The fabrication process requires only one mask and one etch step, so that the fabrication has the advantages of low cost, short processing period, and facilitation of miniaturization. The pump is equipped with a glass cover board so as to conveniently observe the flow status. Pump-chambers and diffuser elements are fabricated by the anisotropic KOH-etch technique on the silicone substrate, and the convex corner is designed to compensate for an anisotropic etch. The driving force of the micropump is produced by the PZT piezoelectric actuator. The pump performance with both actuators actuated in anti- or same-phase mode is also researched. The result indicates that the micropump achieves great performance with the actuators working at anti-phase. This may be because the liquid flows steadily, pulse phenomenon is very weak, and the optimal working frequency, pump back pressure, and flow rate are both double that of the pump driven in same-phase.

关键词： diffuser/nozzle Si/Glass phenomenon rectification diffuser/nozzle micropump frequency

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Experimental and CFD analysis of nozzle position of subsonic ejector

Xilai ZHANG, Shiping JIN, Suyi HUANG, Guoqing TIAN

《能源前沿（英文）》 2009年第3卷第2期页码 167-174 doi: 10.1007/s11708-009-0001-5

摘要： The influence of nozzle position on the performance of an ejector was analyzed qualitatively with free jet flow model. Experimental investigations and computational fluid dynamics (CFD) analysis of the nozzle position of the subsonic ejector were also conducted. The results show that there is an optimum nozzle position for the ejector. The ejecting coefficient reaches its maximum when the nozzle is positioned at the optimum and decreases when deviating. Moreover, the nozzle position of an ejector is not a fixed value, but is influenced greatly by the flow parameters. Considering the complexity of the ejector, CFD is reckoned as a useful tool in the design of ejectors.

关键词： ejector nozzle position ejecting coefficient CFD

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Depth of cut models for multipass abrasive waterjet cutting of alumina ceramics with nozzle oscillation

Jun WANG

《机械工程前沿（英文）》 2010年第5卷第1期页码 19-32 doi: 10.1007/s11465-009-0082-1

摘要： An experimental study of the depth of cut in multipass abrasive waterjet (AWJ) cutting of alumina ceramics with controlled nozzle oscillation is presented. It is found that this cutting technique can significantly increase the depth of cut by an average of 50.8% as compared to single pass cutting without nozzle oscillation under the corresponding cutting conditions and within the same cutting time. Predictive models for the depth of cut are then developed. The modelling process starts with single pass cutting using a dimensional analysis technique and the particle erosion theories applied to alumina ceramics, before progressing to the development of the models for multipass cutting. The models are finally assessed both qualitatively and quantitatively with experimental data. It is shown that the model predictions are in good agreement with the experimental data with the average deviations of about 1%.

关键词： abrasive waterjet engineering ceramics depth of cut cutting performance nozzle oscillation machining

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Investigation into the influence of diffuser stagger angles on the flow field and performance of a centrifugal

XI Guang, DING Haiping, YUAN Minjian, ZHANG Chunmei, ZHOU Li

《能源前沿（英文）》 2007年第1卷第3期页码 290-294 doi: 10.1007/s11708-007-0041-7

摘要： The performance graphs of a centrifugal compressor under different diffuser stagger angles were measured, and the influence of different stagger angles of vanes on the stage performance as well as flow field was investigated numerically. The results show that the performance graph shifts when the diffuser stagger angle is altered; the influence of different stagger angles of vanes on the flow field inside the centrifugal compressor is great. Large scale vortices appear on the diffuser vane under larger incidence. An optimal diffuser stagger angle should exist at a specified flow rate to make the characteristic of the flow optimized. The incidence corresponding to the highest efficiency is not 0º at the design condition.

关键词： diffuser stagger incidence different stagger flow centrifugal compressor

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Influence of nozzle height to width ratio on ignition and NO

Liutao SUN, Yonghong YAN, Rui SUN, Zhengkang PENG, Chunli XING, Jiangquan WU

《能源前沿（英文）》 2021年第15卷第2期页码 431-448 doi: 10.1007/s11708-021-0726-3

摘要： To improve the ignition behavior and to reduce the high NO emissions of blended pulverized fuels (PF) of semicoke (SC), large-scale experiments were conducted in a 300 kW fired furnace at various nozzle settings, i.e., ratios (denoted by / ) of the height of the rectangular burner nozzle to its width of 1.65, 2.32, and 3.22. The combustion tests indicate that the flame stability, ignition performance, and fuel burnout ratio were significantly improved at a nozzle setting of / = 2.32. The smaller / delayed ignition and caused the flame to concentrate excessively on the axis of the furnace, while the larger / easily caused the deflection of the pulverized coal flame, and a high-temperature flame zone emerged close to the furnace wall. NO emissions at the outlet of the primary zone decreased from 447 to 354 mg/m (O = 6%), and the ignition distance decreased from 420 to 246 mm when the / varied from 1.65 to 3.22. Furthermore, the ratio (denoted by / ) of the strong reduction zone area to the combustion reaction zone area was defined experimentally by the CO concentration to evaluate the reduction zone. The / rose monotonously, but its restraining effects on NO formation decreased as / increased. The results suggested that in a test furnace, regulating the nozzle / conditions sharply reduces NO emissions and improves the combustion efficiency of SC blends possessing an appropriate jet rigidity.

关键词： rectangular jet burner nozzle height to width ratio ignition characteristics pyrolyzed semicoke (SC) and bituminous blend NO_x formation

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Numerical analysis of rotating stall characteristics in vaneless diffuser with large width-radius ratio

GAO Chuang, GU Chuangang, WANG Tong, DAI Zhengyuan

《能源前沿（英文）》 2008年第2卷第4期页码 457-460 doi: 10.1007/s11708-008-0071-9

摘要： A two-dimensional model, where the influence of wall boundary layers is neglected and inlet jet-wake velocity patterns are prescribed, was applied to simulate one vaneless diffuser with a large width-radius ratio. The impact of diffuser length, impeller blade number, etc. on the rotating stall was analyzed. Computational results show that a different mechanism does exist for diffusers with large width-radius ratios. Comparison with related conclusions and references is supportive of the model.

关键词： Comparison Computational two-dimensional influence different mechanism

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Multi-objective optimization of a 3D vaneless diffuser based on fuzzy theory

GAO Chuang, GU Chuangang, WANG Tong, SHU Xinwei

《能源前沿（英文）》 2008年第2卷第1期页码 66-70 doi: 10.1007/s11708-008-0006-5

摘要： An optimization model based on fuzzy theory was set up and the corresponding Interactive modified simplex (IMS) method was developed to solve it. Both static pressure recovery and total pressure loss were considered in the model. Computational fluid dynamics (CFD) method was applied to solve the Reynolds-Averaged Navier-Stokes equation (RANS) and to find flow field distribution to get the value of the object function. After receiving the new shroud curve, grid movement and redrawing technology were adopted to avoid grid-line crossing and negative cells. The shroud curve was fitted with B-spline. The optimized results concur with the results reported in references.

关键词： Computational pressure recovery B-spline technology corresponding Interactive

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Flow behavior of liquid-solid coupled system of piezoelectric micropump

LU Lijun, WU Jiankang

《机械工程前沿（英文）》 2008年第3卷第1期页码 50-54 doi: 10.1007/s11465-008-0003-8

摘要： This paper employs a shallow water model and the finite element method to approximate periodical flows of a micropump to a two-dimensional thickness-averaged flow. A liquid-solid coupled system equation of the micropump is presented. Through the mode analysis of the liquid-solid coupled system, the first-order natural frequency, diaphragm vibration shape and amplitude-frequency relationship are obtained. The vibration response of the diaphragm is calculated when an external electric field is applied. Based on the thickness-averaged flow equation, the periodical flow of the micropump is studied using the finite volume method to investigate the flow behavior and flow rate-frequency characteristics. Numerical results indicate that an optimal working frequency can be obtained, at which the flow rate of the micropump achieves the maximum when the external electric voltage is fixed.

关键词： amplitude-frequency relationship first-order micropump diaphragm vibration electric

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Insult of gastroesophageal reflux on airway: clinical significance of pharyngeal nozzle

null

《医学前沿（英文）》 2015年第9卷第1期页码 117-122 doi: 10.1007/s11684-014-0343-1

摘要：

At the very time of global paying the highest attention to the worst insults of smoking as well as haze on the airway, everybody knows both are exogenous and noticeable. However, people mostly, including many medical personnel, do not know how badly the gastroesophageal reflux (GER) insults on our own airway. Symptoms of GER are commonly seen as heartburn and regurgitation, which can be mostly tolerated. However, when the up going gastric content reversely passes the esophagus and then the distal pharynx, where it appears a beak like stricture, serving as a nozzle, so as to produce numerous micro-particles and reach the oro-nasal cavity and also the airway causing allergic rhinitis and asthmatic attacks, even pulmonary parenchyma lesions. It will reduce life quality or even jeopardize life. The point that the endogenous insult appears in the respiratory system, but originates from the digestive tract is not well known and often undiagnosed and not correctly treated. The GER induced airway challenge is a treatable and preventive entity, as soon as a diagnosis is made, a good relief could be expected by means of life style adjustment, medicine, or fixation of the patulous cardia through radiofrequency or fundoplication. The author Dr. Zhonggao Wang had suffered it for long and symptoms disappeared for 8 years after anti-reflux surgery. Here is a presentation of Dr. Zhonggao Wang and his team’s work and would call attention to the public so as to recognize this relatively unknown entity — a treatable condition occurring from human itself, but not from outside surroundings as smoking or haze does.

关键词： gastroesophageal reflux airway pharyngeal nozzle micro-aspiration asthma

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A new approach for fuel injection into a solar receiver/reactor: Numerical and experimental investigation

M Helal Uddin, Nesrin Ozalp, Jens Heylen, Cedric Ophoff

《化学科学与工程前沿（英文）》 2018年第12卷第4期页码 683-696 doi: 10.1007/s11705-018-1782-z

摘要：

An innovative and efficient design of solar receivers/reactors can enhance the production of clean fuels via concentrated solar energy. This study presents a new jet-type burner nozzle for gaseous feedstock injection into a cavity solar receiver inspired from the combustion technology. The nozzle design was adapted from a combustion burner and successfully implemented into a solar receiver and studied the influence of the nozzle design on the fluid mixing and temperature distribution inside the solar receiver using a 7 kW solar simulator and nitrogen as working fluid. Finally, a thorough computational fluid dynamics (CFD) analysis was performed and validated against the experimental results. The CFD results showed a variation of the gas flow pattern and gas mixing after the burner nozzle adaptation, which resulted an intense effect on the heat transfer inside the solar receiver.

关键词： solar reactor nozzle CFD heat transfer mixing and recirculation

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一种采用三流体喷嘴喷雾干燥技术高效构筑齿科修复用多功能团簇体填料的通用策略 Article

杨丹蕾, 王丹, 牛昊, 王瑞莉, 刘梅, 章非敏, 王洁欣, 朱美芳

《工程（英文）》 2022年第8卷第1期页码 138-147 doi: 10.1016/j.eng.2021.08.001

摘要：

齿科复合树脂对多功能填料有很高的要求。本研究首次采用配备三流体喷嘴的喷雾干燥设备构筑由不同功能纳米颗粒组成的高性能复合纳米颗粒团簇体，并将其作为填料应用于齿科修复。三流体喷嘴的应用可以有效避免喷雾干燥前需将带有相反电荷的纳米粒子混合而发生的团聚现象，从而构筑形貌规则的复合纳米颗粒团簇体填料。对于SiO₂-ZrO₂二元体系，尽管引入了ZrO₂纳米颗粒，采用三流体喷嘴构筑的SiO₂-ZrO₂复合团簇体可以使复合树脂保持优异的力学性能[弯曲强度、弯曲模量、压缩强度和硬度分别为(133.3 ± 4.7) MPa、(8.8 ± 0.5) GPa、(371.1 ± 13.3) MPa和(64.5 ± 0.7) HV]，但使用二流体喷嘴构筑的SiO₂-ZrO₂复合团簇体填充所得复合树脂的力学性能显著下降。此外，对SiO₂-ZrO2复合团簇体填料进行热处理后再进行填充，能够显著提高复合树脂的力学性能和X射线阻射性。含有10 wt.%以上ZrO₂纳米颗粒的复合树脂可以满足其对X射线阻射性的要求。更重要的是，该方法可以推广到三元或四元体系。填充了SiO₂-ZrO₂-ZnO 复合团簇体填料（三者质量比为56∶10∶4）的复合树脂，除了具有良好的力学性能和X射线阻射性外，还展现出高的抗菌活性（抗菌率> 99%）。因此，采用三流体喷嘴的喷雾干燥技术在高效构筑多功能团簇体填料方面具有巨大的潜力。

关键词：多功能团簇体填料三流体喷嘴喷雾干燥技术机械性能抗菌性能 X射线阻射性齿科复合树脂

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Droplet spectra and high-speed wind tunnel evaluation of air induction nozzles

Qing TANG, Liping CHEN, Ruirui ZHANG, Min XU, Gang XU, Tongchuan YI, Bin ZHANG

《农业科学与工程前沿（英文）》 2018年第5卷第4期页码 442-454 doi: 10.15302/J-FASE-2017169

摘要：

A series of air induction nozzles were tested in a high-speed wind tunnel. Droplet size spectra were measured for four air induction nozzles (IDK-120-01, IDK-120-02, IDK-120-03 and IDK-120-04) each at three spray pressures (0.3, 0.4 and 0.5 MPa) and seven different air velocities (121.7, 153.4, 185.5, 218.4, 253.5, 277.5 and 305.5 km·h ). The measurement distance (0.15, 0.25 and 0.35 m) from the nozzle orifice was found to be important for the atomization of the droplets. The response surface method was used to analyze the experimental data. The results indicated that v and v of the droplets decreased quasi-linearly with increased wind speed, while v was affected by the quadratic of wind speed. v , v and v of the droplets were all proportional to the orifice size, and were not markedly influenced by the spray pressure. The percentage of the spray volume consisting of droplets with a diameter below 100 mm (%<100 mm) was found to be quadratically related to wind speed, and was not markedly influenced by the spray pressure and orifice size. However, the effect of the orifice size on the %<200 mm could not be ignored.

关键词： air induction nozzle wind tunnel aerial spray droplet size spectra

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Characterization of aerodynamic performance of wind-lens turbine using high-fidelity CFD simulations

Islam HASHEM, Aida A. HAFIZ, Mohamed H. MOHAMED

《能源前沿（英文）》 2022年第16卷第4期页码 661-682 doi: 10.1007/s11708-020-0713-0

摘要： Wind-lens turbines (WLTs) exhibit the prospect of a higher output power and more suitability for urban areas in comparison to bare wind turbines. The wind-lens typically comprises a diffuser shroud coupled with a flange appended to the exit periphery of the shroud. Wind-lenses can boost the velocity of the incoming wind through the turbine rotor owing to the creation of a low-pressure zone downstream the flanged diffuser. In this paper, the aerodynamic performance of the wind-lens is computationally assessed using high-fidelity transient CFD simulations for shrouds with different profiles, aiming to assess the effect of change of some design parameters such as length, area ratio and flange height of the diffuser shroud on the power augmentation. The power coefficient ( ) is calculated by solving the URANS equations with the aid of the SST model. Furthermore, comparisons with experimental data for validation are accomplished to prove that the proposed methodology could be able to precisely predict the aerodynamic behavior of the wind-lens turbine. The results affirm that wind-lens with cycloidal profile yield an augmentation of about 58% increase in power coefficient compared to bare wind turbine of the same rotor swept-area. It is also emphasized that diffusers (cycloid type) of small length could achieve a twice increase in power coefficient while maintaining large flange heights.

关键词： shroud diffuser-augmented wind turbine (DAWT) Betz limit aerodynamics computational fluid dynamics (CFD)