scholarly journals A Theoretical and Experimental Study of a Piezoelectric Pump with Two Elastic Chambers

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5867
Author(s):  
Xiaolong Zhao ◽  
Dingxuan Zhao ◽  
Qinghe Guo
Keyword(s):  
Flow Rate ◽  
Dynamic Load ◽  
Structural Parameters ◽  
Experimental Tests ◽  
Maximum Output ◽  
Piezoelectric Pump ◽  
Piezoelectric Vibrator ◽  
Output Performance ◽  
Key Factor ◽  
The Impact

The paper is a continuation of our work on the dynamic load in piezoelectric pumps. In the study, the dynamic load of liquid in the pipelines was proposed as a key factor that limits the output performance of piezoelectric pumps. To decrease the dynamic load, a piezoelectric pump with two elastic chambers was proposed in our previous published work. In this paper, the performance and key parameters of the piezoelectric pump with two elastic chambers were studied through theoretical analyses and experimental tests. After establishing the mathematical model of the piezoelectric pump with two elastic chambers, the paper theoretically analyzed the performance of the pump and the effect of different structural parameters on the performance. Then prototypes with a range of structural parameters were developed and tested. As revealed from the test results, the elastic chamber effectively decreased the dynamic load of the liquid in the pipelines and the flow rate of the prototype with two elastic chambers was higher than that of the prototype with one or no elastic chamber. However, the elastic chamber did not lead to the increase in the maximum output backpressure of the prototype. Adopting an elastic diaphragm exhibiting a smaller stiffness or a larger diameter could help decrease the dynamic load of the liquid. The elastic chamber more significantly impacted the flow rate of the piezoelectric pump with long pipelines. The pump chamber height had a significant effect on the output performance of the piezoelectric pump with two elastic chambers, which is consistent with the conventional piezoelectric pump. At the height of 0.2 mm, the flow rate of the prototype with two elastic chambers was peaked at 7.7 mL/min; at the height of 0.05 mm, the output backpressure reached the highest of 28.2 kPa. The dynamic load could decrease the amplitude of the piezoelectric vibrator, whereas the prototype with two elastic chambers could effectively reduce the impact of dynamic load on the piezoelectric vibrator. The flow rate decreased almost linearly with the backpressure. Under the same backpressure, the flow rate of the prototype with two elastic chambers was higher than that of the prototype without elastic chamber, and the flow rate difference between the two prototypes gradually decreased with the backpressure.

scholarly journals Research on Inlet and Outlet Structure Optimization to Improve the Performance of Piezoelectric Pump

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 735 ◽  
Author(s):  
Xiaolong Zhao ◽  
Dingxuan Zhao ◽  
Jiantao Wang ◽  
Tao Li
Keyword(s):  
Flow Rate ◽  
Dynamic Load ◽  
Maximum Flow ◽  
Fluid Simulation ◽  
Maximum Output ◽  
Piezoelectric Pump ◽  
Pump System ◽  
Output Performance ◽  
Pump Inlet ◽  
Application Requirements

As piezoelectric pumps are used in more fields, they are gradually failing to meet the application requirements due to their low output performance. Therefore, improving the output performance of piezoelectric pumps helps to expand their applications. This paper argued that the dynamic load of liquid in the inlet and outlet pipelines was an important factor that weakened the performance of piezoelectric pumps. Therefore, in order to reduce the dynamic load, it was proposed to replace the conventional piezoelectric pump inlet and outlet by an elastic inlet and outlet. After introducing the structure and working principle of elastic inlet and outlet, the mechanism of reducing the dynamic load by elastic inlet and outlet was analyzed. Then, the influence of the elastic cavity height on the performance of the piezoelectric pump was studied from both fluid simulation and theoretical analysis. Finally, several prototypes were made. The effectiveness of the elastic inlet and outlet on improving the performance of the prototype and the effect of the elastic cavity height on the performance of the prototype were tested, respectively. The test results showed that the elastic inlet and outlet effectively improved the flow rate and output backpressure without increasing the maximum output backpressure. The maximum flow rate of the pump system without load was increased by 36%. In addition, the elastic cavity height adversely affected the flow rate and output backpressure of the prototypes, but had no effect on the maximum output backpressure. In summary, the elastic inlet and outlet can effectively increase the output performance of the piezoelectric pump, but the design height should be appropriately reduced.

scholarly journals Design and Experiment Using Flexible Bumps for Piezoelectric-Driven Hydraulically Amplified Braille Dot Display

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 795
Author(s):  
Xiaochao Tian ◽  
Yuze Sun ◽  
Zhiyao Li ◽  
Hu Wang ◽  
Zhicong Wang ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Water Discharge ◽  
Experimental Tests ◽  
Output Displacement ◽  
Amplification Ratio ◽  
Fluid Resonance ◽  
Piezoelectric Vibrator ◽  
Flexible Film ◽  
Touch Sensitivity ◽  
Sensitivity Standard

This paper describes the design of a piezoelectric-driven hydraulically amplified Braille-flexible bump device that enables the flexible formation of Braille characters. A piezoelectric vibrator is used to excite fluid resonance in a cavity, and displacement is realized by compressing the fluid, allowing Braille character dots to be formed. First, the structural design and working principle of the device, as well as the method used to drive the fluid, are explained. Expressions for the output displacement and amplification ratio of the flexible film and piezoelectric vibrator are then obtained through kinetic analysis of the system unit. Subsequently, the structural parameters that affect the output displacement and the liquid amplification are described. Finally, experimental tests of the system are explained. The results indicate that the output displacement of the contact formed by the flexible film reaches 0.214 mm, satisfying the requirements of the touch sensitivity standard for the blind, when the fluid cavity diameter measures 31 mm and the resonance frequency is 375.4 Hz. The corresponding water discharge is 8.8 mL. This study proves that constructing a Braille bump device in this way is both feasible and effective.

scholarly journals Improving Output Performance of a Resonant Piezoelectric Pump by Adding Proof Masses to a U-Shaped Piezoelectric Resonator

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 500
Author(s):  
Jian Chen ◽  
Wenzhi Gao ◽  
Changhai Liu ◽  
Liangguo He ◽  
Yishan Zeng
Keyword(s):  
Flow Rate ◽  
Maximum Flow ◽  
Working Fluid ◽  
Driving Voltage ◽  
Piezoelectric Resonator ◽  
Piezoelectric Pump ◽  
Compact Structure ◽  
Output Performance ◽  
Volume Efficiency ◽  
Working Efficiency

This study proposes the improvement of the output performance of a resonant piezoelectric pump by adding proof masses to the free ends of the prongs of a U-shaped piezoelectric resonator. Simulation analyses show that the out-of-phase resonant frequency of the developed resonator can be tuned more efficiently within a more compact structure to the optimal operating frequency of the check valves by adjusting the thickness of the proof masses, which ensures that both the resonator and the check valves can operate at the best condition in a piezoelectric pump. A separable prototype piezoelectric pump composed of the proposed resonator and two diaphragm pumps was designed and fabricated with outline dimensions of 30 mm × 37 mm × 54 mm. Experimental results demonstrate remarkable improvements in the output performance and working efficiency of the piezoelectric pump. With the working fluid of liquid water and under a sinusoidal driving voltage of 298.5 Vpp, the miniature pump can achieve the maximum flow rate of 2258.9 mL/min with the highest volume efficiency of 77.1% and power consumption of 2.12 W under zero backpressure at 311/312 Hz, and the highest backpressure of 157.3 kPa under zero flow rate at 383 Hz.

Valveless Piezoelectric Pump with Reverse Diversion Channel

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1712
Author(s):  
Yongming Yao ◽  
Zhicong Zhou ◽  
Huiying Liu ◽  
Tianyu Li ◽  
Xiaobin Gao
Keyword(s):  
Reverse Flow ◽  
Structural Parameters ◽  
Maximum Flow ◽  
Simulation Software ◽  
Return Flow ◽  
Piezoelectric Pump ◽  
Output Performance ◽  
Diversion Channel ◽  
Tesla Valve ◽  
Valveless Piezoelectric Pump

In order to reduce backflow and improve output performance, a valveless piezoelectric pump with a reverse diversion channel was produced. The channel was designed based on the structure of the Tesla valve, which has no moving parts and can produce a high-pressure drop during reverse flow. Therefore, this special flowing channel can reduce the backflow of a valveless piezoelectric pump, which has the characteristic of one-way conduction. This work first revealed the relationship between the main structural parameters of the Tesla valve and the kinetic energy difference of liquid. Then, by using simulation software, the structure was verified to have the characteristics of effective suppression of the backflow of valveless piezoelectric pumps. Through setting multiple simulations, some important parameters that include the optimal height between the straight channels (H), the optimal angle (α) between the straight channel and the inclined channel, as well as the optimal radius (R) of the channel were confirmed. Finally, a series of prototypes were fabricated to test the output performance of this valveless piezoelectric pump. Comparing the experimental results, the optimal parameters of the Tesla valve were determined. The results suggest that when the parameters of the Tesla valve were H = 8 mm, α = 30°, and R = 3.4 mm, the output performance of this piezoelectric pump became best, which had a maximum flow rate of 79.26 mL/min with a piezoelectric actuator diameter of 35 mm, an applied voltage of 350 Vp-p, and a frequency of 28 Hz. The effect of this structure in reducing the return flow can be applied to fields such as agricultural irrigation.

Experimental Studies on Triple-Chamber Piezoelectric Pump with Triple Vibrators under Different Working Modes

2014 ◽  
Vol 915-916 ◽  
pp. 366-371
Author(s):  
Bing Han ◽  
Zhong Hua Zhang ◽  
Shu Yun Wang ◽  
Jun Wu Kan ◽  
Ze Hui Ma ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Experimental Studies ◽  
Test Results ◽  
Piezoelectric Pump ◽  
Output Performance ◽  
Serial Connection ◽  
Working Principle ◽  
Working Frequency ◽  
Working Parameters ◽  
Left Middle

The structure and working principle of serial-connection 3-chamber PZT pump was introduced, and the output performance of the PZT pump was analyzed under different working modes. The pump was tested, respectively, first with each of the three actuators at different location being actuated solely, and then with random two of the three actuators at different location being actuated (in anti-phase) synchronously. The test results show that changing the driving strategy can change the output performance of the piezoelectric pump, with the structural parameters, working parameters and connection Strategy determined. At a voltage of 150 V, the maximal flowrate and optimal working frequencies for the pump under working mode of left, middle, right chambers actuated solely are 9/7.5/11 ml/min and 260/380/720 Hz respectively. The maximal flowrate and the optimal working frequency for the pump under working mode of left and middle chambers/middle and right chambers actuated synchronously are 17/28 ml/min and 460/600 Hz respectively.

Development of a piezoelectric pump with ball valve structure

2021 ◽  
pp. 1045389X2199417
Author(s):  
Qiaosheng Pan ◽  
Haiyang Jiang ◽  
Ziliang Huang ◽  
Bin Huang ◽  
Ruijun Li ◽  
...  
Keyword(s):  
Flow Rate ◽  
Check Valve ◽  
Experimental Tests ◽  
Vertical Displacement ◽  
Ball Valve ◽  
Piezoelectric Pump ◽  
Analogue Circuit ◽  
Current Design ◽  
Study Designs ◽  
Rate Pulsation

This study designs, fabricates and tests a piezoelectric pump with the structure of a polystyrene ball check valve. The structure of the check valve consists of three layers of specially designed polymethylmethacrylate plates and six polystyrene balls, which forms a particular three-layer constraint mechanism to limit the lateral and vertical displacement of the balls. The assembly of the ball valve can be completed with a simple placing operation, which simplifies the assembly process of the entire pump. The balls are lightweight, which is beneficial for working at high frequencies. The current design adopts two compressible spaces, and the equivalent analogue circuit of compressible spaces is established and analysed. Experimental results indicate that compressible spaces can alleviate the burden in the actuator and smoothen the flow rate pulsation in the long flow channel. The theoretical analysis and experimental tests reveal that this new piezoelectric pump is self-priming. A high flow rate of 99.6 mL/min and the maximum back pressure of 15.3 kPa are obtained when the pump is driven with a sinusoidal voltage of 448 Vpp at the resonant frequency of 790 Hz.

scholarly journals Influence of the Design Solutions of Extruder Screw Mixing Tip on Selected Properties of Wheat Bran-Polyethylene Biocomposite

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2120 ◽  
Author(s):  
Emil Sasimowski ◽  
Łukasz Majewski ◽  
Marta Grochowicz
Keyword(s):  
Flow Rate ◽  
Wheat Bran ◽  
Experimental Tests ◽  
Extrusion Process ◽  
Design Solution ◽  
Polyethylene Matrix ◽  
Melt Flow Rate ◽  
Extruder Screw ◽  
Processing Properties ◽  
The Impact

The study investigated the impact of the extruder screw design solution—the intensive mixing tip used—on the course of the extrusion process and the properties of the obtained biocomposite extrudate. A lignocellulosic wheat bran biocomposite based on a low-density polyethylene matrix was extruded. Three mixing tips of the screw were used interchangeably: apineapple tip, a cut rings tip, and a Maddock tip. The experimental tests carried out included the production of an extrudate with a mass content of bran altered within the range from 10% to 50%. Processing properties such as the melt flow rate (MFR) and mass flow rate of the extruded biocomposite were determined. Selected physical, mechanical, and structural properties of the biocomposite extrudate obtained with the use of the three tested mixing tips at five bran contents were tested.

Simulation Research of the Impact on Sensitivity by Structural Parameters of Disc-Type Inner UHF Sensors Used for GIS PD Detection

2014 ◽  
Vol 1070-1072 ◽  
pp. 1044-1049
Author(s):  
Yong Yong Jia ◽  
Jing Gang Yang ◽  
Lin Rong ◽  
Ke Zhao
Keyword(s):  
Performance Evaluation ◽  
Simulation Model ◽  
Structural Parameters ◽  
Simulation Research ◽  
Sensor Performance ◽  
Key Indicator ◽  
Sensor Technique ◽  
Key Factor ◽  
The Impact ◽  
Higher Sensitivity

The UHF method is one of the most important partial discharge (PD) detection means for GIS, while sensor technique is the key factor of the UHF method. In comparison with external sensors, inner sensors can achieve higher sensitivity. The paper firstly presents a key indicator of the sensor performance evaluation, and builds a simulation model of that. Secondly, the paper implements simulation research on the PD detection performance of the disc-type sensor, especially on the impacts caused by structural parameters based on the simulation model. The research achievements of the paper may provide reference of performance evaluation and design optimization for disc-type UHF sensors.

scholarly journals Determining the influence of structural and operational parameters of a double bearing on the thickness of its disc

2021 ◽  
Vol 3 (7 (111)) ◽  
pp. 68-73
Author(s):  
Vladimir Nazin
Keyword(s):  
Flow Rate ◽  
Power Plants ◽  
Bending Strength ◽  
Structural Parameters ◽  
Successive Approximations ◽  
Stable Operation ◽  
Centrifugal Forces ◽  
Total Load ◽  
Reynolds Equations ◽  
The Impact

This paper describes the main advantages of hydrostatic dynamic bearings of the double type, which have several lubricant films. It is indicated that they have an increased carrying capacity, by 1.8 times, and an extended range of stable operation, by 1.5 times, compared to conventional sleeve bearings with one lubricating film. The importance of determining the thickness of the bearing disk has been demonstrated, as it affects its durability. The goal was to investigate the impact of changes in the operational and structural parameters of a double bearing on the thickness of its disk. A sequence for determining the disk thickness has been proposed, including a joint solution to Reynolds equations, the balance of work fluid flow rate, as well as determining the loads acting on a bearing disk, which makes it possible to rationally assign the thickness of the bearing disk. The most common and effective methods of successive approximations have been used in the numerical implementation of Reynolds equations and flow rate balances. The action of centrifugal forces caused by the rotation of the disk has been taken into consideration in determining the total load acting on the bearing disk. The bending strength of the bearing disk was considered under its exposure to the total load. It was noted that due to the high flow rate of the working liquid pumped through the bearing, and the small change in the temperature of the liquid inside the bearing, the temperature deformations of the disk were not taken into consideration. The magnitude of change in the thickness of the double bearing disk has been determined, caused by the action of centrifugal forces in the examined range of angular speeds of the disk's rotation with the shaft. The reported results could be especially useful in the design of rotor supports for nuclear power plants where bearings have large dimensions, as well as for other units in power plants.

Primary Stability of Uncemented Total Hip Stems with Different Ceramic and Titanium Surface Coatings

2016 ◽  
Vol 696 ◽  
pp. 165-170
Author(s):  
Rebecca Dammer ◽  
Andreas Fritsche ◽  
Helmut D. Link ◽  
Carmen Zietz ◽  
Rainer Bader
Keyword(s):  
Surface Roughness ◽  
Calcium Phosphate ◽  
Primary Stability ◽  
Experimental Tests ◽  
Test Machine ◽  
Total Hip ◽  
Pull Out ◽  
Key Factor ◽  
Hip Stems ◽  
The Impact

The necessity of coatings for endoprosthetic implants is discussed controversially. Thereby hydroxyapatite coatings are objects of the debate [1, 2]. Therefore, we investigated four different coatings (calcium-phosphate (CaP), titanium-calcium-phosphate (TiCaP), titanium-plasma-spray (TPS) and bilayer-composite calcium-phosphate (CaP-bc)) in comparison with rough uncoated test specimens to evaluate the impact of the osteoconductive coatings on the initial implant stability which is the key factor for its secondary stability. Dimensions of the test specimens were defined according to a conventional total hip stem and their geometry was simplified to a conical one for comparison of the surface-related parameters. The specimens were force-controlled pressed in artificial bone counterparts made of foam material while the displacement was monitored by the test machine to determine the subsidence behavior. Consecutively a displacement-controlled axial extraction of the test specimens was performed and the pull-out force was recorded. Roughness and geometry of the test specimens before testing were measured and correlated to type of coating and initial stability. The uncoated specimens showed highest extraction forces (3.9 kN) with moderate surface roughness compared to the coated specimens. In contrary to our assumption no correlation between surface roughness and the measured subsidence as well as pull-out force was found and a reduced subsidence or increased pull-out force for the different titanium and calcium-phosphate coatings could not be derived from the experimental tests.

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