scholarly journals A Piezoelectric Resonance Pump Based on a Flexible Support

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 169 ◽  
Author(s):  
Jiantao Wang ◽  
Xiaolong Zhao ◽  
Xiafei Chen ◽  
Haoren Yang
Keyword(s):  
Volume Change ◽  
Structural Parameters ◽  
Peak Voltage ◽  
Output Pressure ◽  
Piezoelectric Resonance ◽  
Flexible Support ◽  
Pump Chamber ◽  
Chamber Height ◽  
Maximum Value ◽  
Resonance Principle

Small volume changes are important factors that restrict the improvement of the performance of a piezoelectric diaphragm pump. In order to increase the volume change of the pump chamber, a square piezoelectric vibrator with a flexible support is proposed in this paper and used as the driving unit of the pump. The pump chamber diaphragm was separated from the driving unit, and the resonance principle was used to amplify the amplitude of the pump diaphragm. After analyzing the working principle of the piezoelectric resonance pump and establishing the motion differential equation of the vibration system, prototypes with different structural parameters were made and tested. The results show that the piezoelectric resonance pump resonated at 236 Hz when pumping air. When the peak-to-peak voltage of the driving power was 220 V, the amplitude of the diaphragm reached a maximum value of 0.43933 mm, and the volume change of the pump was correspondingly improved. When the pump chamber height was 0.25 mm, the output flow rate of pumping water reached a maximum value of 213.5 mL/min. When the chamber height was 0.15 mm, the output pressure reached a maximum value of 85.2 kPa.

scholarly journals Coupled Fluid–Solid Numerical Simulation for Flow Field Characteristics and Supporting Performance of Flexible Support Cylindrical Gas Film Seal

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Junfeng Sun ◽  
Meihong Liu ◽  
Zhen Xu ◽  
Taohong Liao ◽  
Xiangping Hu ◽  
...  
Keyword(s):  
Flow Field ◽  
Film Thickness ◽  
Fluid Dynamic ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
High Rotational Speed ◽  
Flexible Support ◽  
Flow Field Characteristics

A new type of cylindrical gas film seal (CGFS) with a flexible support is proposed according to the working characteristics of the fluid dynamic seal in high-rotational-speed fluid machinery, such as aero-engines and centrifuges. Compared with the CGFS without a flexible support, the CGFS with flexible support presents stronger radial floating characteristics since it absorbs vibration and reduces thermal deformation of the rotor system. Combined with the structural characteristics of a film seal, an analytical model of CGFS with a flexible wave foil is established. Based on the fluid-structure coupling analysis method, the three-dimensional flow field of a straight-groove CGFS model is simulated to study the effects of operating and structural parameters on the steady-state characteristics and the effects of gas film thickness, eccentricity, and the number of wave foils on the equivalent stress of the flexible support. Simulation results show that the film stiffness increases significantly when the depth of groove increases. When the gas film thickness increases, the average equivalent stress of the flexible support first decreases and then stabilizes. Furthermore, the number of wave foils affects the average foils thickness. Therefore, when selecting the number of wave foils, the support stiffness and buffer capacity should be considered simultaneously.

scholarly journals Multi-Objective Parameter Optimization of Flexible Support System of Optical Mirror

2021 ◽  
Vol 11 (17) ◽  
pp. 8071
Author(s):  
Zujin Jin ◽  
Gang Cheng ◽  
Yusong Pang ◽  
Shichang Xu ◽  
Dunpeng Yuan
Keyword(s):  
Support System ◽  
Structural Parameters ◽  
Control Variable ◽  
Internal Resistance ◽  
Optimized Design ◽  
Force Output ◽  
Multi Objective ◽  
Flexible Support ◽  
Objective Parameter ◽  
The Impact

During the processing of an optical mirror, the performance parameters of the bottom support system would affect the surface forming accuracy of the mirror. The traditional bottom support system has a large unadjustable support stiffness, which increases the difficulty of unloading the impact force generated by the grinding disc. In response to this scenario, a flexible support system (FSS) consisting of 36 support cylinders with beryllium bronze reeds (BBRs) and rolling diaphragms (RDs) as key components is designed. It is necessary to analyze the key components of the support cylinder to reduce its axial movement resistance, ensure a consistent force output of each support point. First, the internal resistance model of a flexible support cylinder is established, and the main factors of internal resistance are then analyzed. Thereafter, the multi-objective structural parameters of the BBR and RD are simulated in ANSYS using the control variable method. The optimal structural parameters of BBR and RD are determined by simulation. Finally, experiments are performed on the RD ultimate pressure, internal resistance of the support cylinder, and consistency of the force output of the FSS. The experimental results show that the support cylinder with the optimized design has good force output consistency, which provides a theoretical basis for the application of FSS in optical mirror processing.

COMPARATIVE CALCULATIONS OF HYDRODYNAMIC AND STRUCTURAL PARAMETERS OF THE ABSORBER TO IMPROVE THE EFFICIENCY OF TREATMENT OF INDUSTRIAL WATERS OF ENTERPRISES

2020 ◽  
Author(s):  
Е.Г. СТЕПАНОВА ◽  
Н.А. ПУХАЧЕВ ◽  
Б.Ю. ОРЛОВ ◽  
М.А. ПЕЧЕРИЦА
Keyword(s):  
Waste Water ◽  
Carbon Dioxide ◽  
Gas Flow ◽  
Structural Parameters ◽  
Active Surface ◽  
Column Diameter ◽  
Gas Flow Rate ◽  
Maximum Value ◽  
Water Pretreatment ◽  
Production Water

Проведены сравнительные гидродинамические и конструктивные расчеты процесса абсорбции углекислого газа и аммиака из отработанных производственных вод пищевых предприятий в аппаратах с деревянными хордовыми насадками, с насадками в виде керамических колец Палля и в адсорбере с хордовыми насадками с предварительной обработкой воды в диафрагменном электролизере. Расчеты выполнены с помощью пакета Mathcad 13. Установлено, что максимальное значение объемной интенсивности при расходе газа 13,9 м3/с и плотности орошения 9,7 Ч 104 м3/(м2 Ч с) получено в адсорбере с хордовыми насадками при предварительной обработке воды в диафрагменном электролизере. Оптимальные размеры колонны адсорбера: диаметр 1,8 м, доля активной поверхности насадки 0,914. Предварительная электрообработка воды перед абсорбцией значительно повышает эффективность очистки, что позволяет очищенную от газовых примесей производственную воду повторно использовать на технологические нужды пищевых предприятий. Comparative hydrodynamic and structural calculations of the process of absorption of carbon dioxide and ammonia from waste water of food enterprises in devices with wooden chord nozzles, with nozzles in the form of ceramic Pall rings and in an adsorber with chord nozzles with pretreatment of water in a diaphragm electrolyzer were carried out. The calculations are performed using the Mathcad 13 package. It was found that the maximum value of the volumetric intensity at a gas flow rate of 13,9 m3/sec and the irrigation density of 9,7 Ч 104 m3/(m2 Ч sec) was obtained in an adsorber with chord nozzles during pretreatment of water pretreatment of water in a diaphragm electrolyzer. Optimal dimensions of the adsorber column: diameter 1,8 m, the proportion of the active surface of the nozzle 0,914. Preliminary electrical treatment of water before absorption significantly increases the efficiency of purification, which allows purified from gas impurities production water to be reused for the technological needs of food enterprises.

A Fluid-Jet Amplifier With Flat Saturation Characteristics

1969 ◽  
Vol 91 (4) ◽  
pp. 734-739 ◽  
Author(s):  
W. S. Griffin
Keyword(s):  
Maximum Output ◽  
Noise Levels ◽  
Output Pressure ◽  
Control Signals ◽  
Maximum Value ◽  
Control Port ◽  
Differential Control ◽  
Percent Decrease

A proportional fluid-jet amplifier has been developed which exhibits flat saturation characteristics and also has reasonable gains, differential output pressures, and noise levels. The amplifier’s output pressure did not drop below 68 percent of its maximum value for any differential control-port pressure in excess of that which caused maximum receiver output. A three-stage, gain block showed less than 3.5 percent decrease in differential output pressure for control signals as high as 200 times their maximum output value.

Influence of pump-chamber height on bubble retention in piezoelectric micro-pump

2017 ◽  
Vol 25 (3) ◽  
pp. 672-679
Author(s):  
陈 松 CHEN Song ◽  
刘 勇 LIU Yong ◽  
阚君武 KAN Jun-wu ◽  
周京京 ZHOU Jing-jing ◽  
杨志刚 YANG Zhi-gang ◽  
...  
Keyword(s):  
Pump Chamber ◽  
Chamber Height ◽  
Micro Pump

STRUCTURAL INSTABILITY AND SUPERCONDUCTIVITY OF THE (Nd, Gd, Ce)2CuO4 SYSTEM

2005 ◽  
Vol 19 (12) ◽  
pp. 607-612
Author(s):  
A. V. POP ◽  
C. PELSHENKE ◽  
O. COZAR
Keyword(s):  
Transition Temperature ◽  
Structural Parameters ◽  
Structural Instability ◽  
Normal Phase ◽  
Partial Substitution ◽  
Critical Transition ◽  
X Ray Diffraction ◽  
Critical Transition Temperature ◽  
X Ray ◽  
Maximum Value

The influence of partial substitution of Nd by Gd and Ce on the Nd 2 CuO 4n-type superconductor was studied by using X-ray diffraction measurements. For x = 0.15 Ce the maximum value of critical transition temperature Tc was obtained. The influence of Gd concentration on the lattice parameters and unit-cell volume was studied in the optimal doped sample (x = 0.15 Ce ) and in the samples with 0≤x≤0.2 Ce . The relation between structural parameters and critical transition temperature was evidenced. The transition from the structural normal phase to the distortion phase was evidenced above y = 0.75 Gd in the optimal Ce -doped sample.

Modelling of Flow Uniformity Among Non-Uniform Cross-Section Microchannels

2007 ◽  
Author(s):  
Minqiang Pan ◽  
Yong Tang ◽  
Yihong Zhang ◽  
Wei Zhou
Keyword(s):  
Cross Section ◽  
Structural Parameters ◽  
Rake Angle ◽  
Considerable Effect ◽  
Flow Uniformity ◽  
Minimum Value ◽  
Symmetrical Distribution ◽  
Maximum Value ◽  
Uniform Cross Section ◽  
Almost All

A model of non-uniform cross-section microchannels for realizing flow uniformity is developed in this work. For easy fabrication of microchannels, only the microchannel widths are changed while the thicknesses remain unchangeable in this model, and the relation of the widths of two adjacent microchannels has been established. A specific case is illustrated to study the influence of structural parameters on the microchannel widths. Result indicates that almost all the microchannel widths have symmetrical distribution. The maximum value appears near the edge while the minimum value in the middle microchannel. For all the structural parameters, the rake angle of manifold has a considerable effect on the microchannel width, and the preset value of microchannel width shows a slight influence.

scholarly journals Effect Of Fabric Layers On Whiteness And Yellowness Indices Of Some Polyester Fabrics Woven With Different Constructional Parameters

2015 ◽  
Vol 15 (2) ◽  
pp. 116-122 ◽  
Author(s):  
Mine Akgun
Keyword(s):  
Structural Parameters ◽  
Suitable Choice ◽  
Polyester Fabrics ◽  
Layer Number ◽  
Maximum Value ◽  
Fabric Layer ◽  
Good Relation

Abstract This paper focuses on the assessment of whiteness indices (WI) changes that occurred in white polyester fabrics according to different fabric layers. Yellowness indices (YI) were also assessed with the WI of fabric samples. White polyester fabrics having different constructional parameters were used, the results showed that WI of polyester fabrics increased up to a certain layer of fabric depending on constructional parameters and compactness of fabric. After a certain layer, WI of fabrics remained almost constant or steeply decreased. YI changed in good relation with whiteness changes. The results showed that the suitable number of fabric layer could be determined for WI measurements according to the compactness and to the structural parameters of the fabric samples. The suitable choice of the fabric layers for whiteness measurement depended on fabric constructional properties and could be made by considering the certain layer number, which could be obtained at the point of the maximum value of whiteness.

Artifacts caused by dehydration and epoxy embedding in TEM

1991 ◽  
Vol 49 ◽  
pp. 338-339
Author(s):  
Hilton H. Mollenhauer
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Volume Change ◽  
Tissue Damage ◽  
Beam Specimen ◽  
Chemical Fixation ◽  
Resin Impregnation ◽  
Storage Vesicles ◽  
A Cell ◽  
Tissue Shrinkage

Various means have been devised to preserve biological specimens for electron microscopy, the most common being chemical fixation followed by dehydration and resin impregnation. It is intuitive, and has been amply demonstrated, that these manipulations lead to aberrations of many tissue elements. This report deals with three parts of this problem: specimen dehydration, epoxy embedding resins, and electron beam-specimen interactions. However, because of limited space, only a few points can be summarized.Dehydration: Tissue damage, or at least some molecular transitions within the tissue, must occur during passage of a cell or tissue to a nonaqueous state. Most obvious, perhaps, is a loss of lipid, both that which is in the form of storage vesicles and that associated with tissue elements, particularly membranes. Loss of water during dehydration may also lead to tissue shrinkage of 5-70% (volume change) depending on the tissue and dehydrating agent.

Short-term volume and turgor regulation in yeast

2008 ◽  
Vol 45 ◽  
pp. 147-160 ◽  
Author(s):  
Jörg Schaber ◽  
Edda Klipp
Keyword(s):  
Dynamic Model ◽  
Volume Change ◽  
Volume Regulation ◽  
Time Course ◽  
Osmotic Shock ◽  
Intracellular Concentration ◽  
Short Term ◽  
Hydrodynamic Property ◽  
Turgor Regulation ◽  
Thermodynamic Framework

Volume is a highly regulated property of cells, because it critically affects intracellular concentration. In the present chapter, we focus on the short-term volume regulation in yeast as a consequence of a shift in extracellular osmotic conditions. We review a basic thermodynamic framework to model volume and solute flows. In addition, we try to select a model for turgor, which is an important hydrodynamic property, especially in walled cells. Finally, we demonstrate the validity of the presented approach by fitting the dynamic model to a time course of volume change upon osmotic shock in yeast.

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