Experimental Study on Small Hydraulic Pump Using Visualization Technique

2019 ◽  
Author(s):  
Jangmi Woo ◽  
Yeonghyeon Gim ◽  
Dong Kee Sohn ◽  
Han Seo Ko
Keyword(s):  
Flow Rate ◽  
Smart Materials ◽  
Maximum Flow ◽  
Sine Wave ◽  
Piezo Actuator ◽  
Driving Frequency ◽  
Hydraulic Pump ◽  
Recent Developments ◽  
Reed Valve ◽  
Critical Components

Abstract Recent developments of smart materials such as piezo devices have been applied to small hydraulic pumps, enabling to meet various demands. For the compact pump, the valves are critical components in the aspect of fluid dynamics. In this study, the flow inside the reed valve port driven by the piezo actuator was experimentally observed. When a sine wave with a driving frequency of 90 Hz was applied, the maximum flow rate could be obtained. It was found that the developed flow opposite to the outlet direction at the root portion of the valve prevented further increase of the flow rate according to the operating frequency.

Design and Testing of a PMN-PT Based Compact Hybrid Actuator

2008 ◽  
Author(s):  
A. Chaudhuri ◽  
N. M. Wereley
Keyword(s):  
Flow Rate ◽  
Smart Materials ◽  
Active Material ◽  
Maximum Flow ◽  
Length Change ◽  
Basic Operation ◽  
Test Results ◽  
Electrostrictive Material ◽  
Hybrid Actuation ◽  
Design And Testing

Substantial research has been conducted in the development of hybrid hydraulic actuators driven by various smart materials. The basic operation of these actuators involves high frequency bidirectional length change of an active material stack (rod) which is converted to unidirectional motion of a hydraulic fluid by a set of active or passive valves. In this paper, we present the design and experimental test results of a compact hybrid actuation driven by the electrostrictive material PMN. The active material was actuated at different frequencies, with variations in the applied voltage and fluid bias pressure to study their effects on performance. The tests were carried out under no-load conditions and also with external weights to find the maximum flow rate and blocked force respectively. The maximum actuator velocity was calculated to be 330 mm/s and the corresponding flow rate was 42.5 cc/s. The blocked force of the actuator was found to be 63 N and the maximum power output was 8 W. Dynamic tests were also conducted to find the PMN stack response without any fluid loads. Results of the experiments are presented and compared with simulation data.

A PZT Micropump With Planar Passive Valves and its Flow Measurements

2009 ◽  
Author(s):  
Chia-Jui Hsu ◽  
Horn-Jiunn Sheen
Keyword(s):  
Flow Rate ◽  
Excitation Frequency ◽  
Maximum Flow ◽  
Driving Frequency ◽  
Flow Measurements ◽  
Piv Measurements ◽  
Optimum Flow Rate ◽  
Micro Piv ◽  
Valve Motion ◽  
Pumping Efficiency

In this paper, a simply-designed reciprocating-type micropump is presented. We also report the coupling effects between the valve motion and the flow behaviors, which were studied using a micro-PIV technique. The fluids were easily driven by a PZT plate and net flow was directed toward the outlet after rectification by two planar passive valves. The results revealed that good pumping performance was obtained even at a low excitation voltage of 10V. The optimum flow rate was measured at a frequency of 0.8kHz and the maximum flow rate was 275μl/min at 30V. The micropump was uniquely characterized by the existence of a linear relationship between the flow rate and the driving frequency, which enabled this micropump to be easily operated and controlled. The experimental results showed that the micropump was reliable in terms of the high linearity and repeatability, which is very favorable for portable microfluidic systems. The micro-PIV measurements of the transient motions of the valve and the flow behaviors clearly revealed that the valve efficiency depended on the mass inertia of the moving part, excitation frequency, and voltage. The present results are useful for the optimum design of this planar passive valve to improve the pumping efficiency.

scholarly journals Analysis of Stiffness Effect on Valve Behavior of a Reciprocating Pump Operated by Piezoelectric Elements

Micromachines ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 894
Author(s):  
Jangmi Woo ◽  
Dong Kee Sohn ◽  
Han Seo Ko
Keyword(s):  
Flow Rate ◽  
Operating Frequency ◽  
Piezo Actuator ◽  
Driving Frequency ◽  
Inlet Valve ◽  
Pump Performance ◽  
Piezoelectric Elements ◽  
Outlet Valve ◽  
Valve Opening ◽  
Reciprocating Pump

This study analyzed the characteristics of a small reciprocating pump with a cantilever valve driven by a piezo actuator. Three types of valves were fabricated to investigate the effect of the valve stiffness on the pump performance and to measure the variation in the flow rate according to the frequency. The flow rate increased with the driving frequency until a certain frequency was reached, and then it started to decrease. The rise in the pressure of the pump was found to increase as the stiffness decreased. The pump performance could be clearly distinguished according to the stiffness of the valve. The observation of the valve movements revealed that the valve opening time did not change regardless of the operating frequency, but it changed with the valve stiffness. The delay in time for the outlet valve increased significantly with an increase in the frequency. It seems that the overlap of the opening time of the inlet valve and the outlet valve plays an important role in pump performance. Therefore, it is advisable to use different designs for the inlet and outlet valves, where the shape and stiffness of the valve are adjusted.

A miniature piezomembrane hydraulic pump with decreasing chambers in succession

2020 ◽  
pp. 1045389X2095361
Author(s):  
Mai Yu ◽  
Song Chen ◽  
Jun Wu Kan ◽  
Zhong Hua Zhang ◽  
Chao Ping Qian ◽  
...  
Keyword(s):  
Flow Rate ◽  
External Load ◽  
Maximum Flow ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Maximum Flow Rate ◽  
Hydraulic Pump ◽  
Optimum Flow Rate ◽  
Output Performance ◽  
High Energy Conversion Efficiency

A miniature piezomembrane hydraulic pump with decreasing chambers in succession (PHPDCS) is presented. The number of chambers in PHPDCS decreases successively in two serial stages. The first stage consists of two chambers in parallel while the second stage consists of only one chamber. The proposed PHPDCS has the comprehensive advantages of serial and parallel connection of multi-chamber and has a high energy conversion efficiency. The prototype of PHPDCS is designed and manufactured. The output performance of PHPDCS under different external loads is investigated by experiments. Experimental results indicate that the optimum flow rate of the proposed PHPDCS is obtained when phase difference between two serial stages is 180°. The output performance of PHPDCS is superior to that of traditional piezoelectric pumps with two chambers in serial (PPCS). At 50 Hz, the maximum flow rate of PHPDCS under external load of 5 kPa is more than twice as high as that of PPCS. Under the external load of 10 kPa, the maximum flow rate of PHPDCS reaches 6.87 mL/min, whereas PPCS has no flow rate output.

scholarly journals Modeling, Vibration Analysis and Fabrication of Micropumps Based on Piezoelectric Transducers

2020 ◽  
Vol 25 (3) ◽  
pp. 383-391
Author(s):  
Yanfang Guan ◽  
Xiangxin Meng ◽  
Yansheng Liu ◽  
Mingyang Bai ◽  
Fengqian Xu
Keyword(s):  
Flow Rate ◽  
Forced Vibration ◽  
Sine Wave ◽  
Piezoelectric Transducers ◽  
Driving Voltage ◽  
Driving Frequency ◽  
External Diameter ◽  
Maximum Displacement ◽  
Wave Signal ◽  
Before And After

The parametric and vibrational characteristics of PZTs (Piezoelectric Transducers) with different diameters before and after coupling are discussed by finite element analysis. It is shown that the vibration stability of the piezoelectric transducer decreases with increasing driving frequency. The PZT's variation of maximum displacement with frequency shows the same trend for different driving conditions according to vibration measurement under conditions of both free and forced vibration (before and after sealing with the pump body). The maximum displacement under forced vibration is less than that under free vibration. The maximum displacement is inversely proportional to the diameter of the transducer and directly proportional to the driving voltage under both free and forced vibration. Micropumps with diffuser/nozzle microvalves are designed and fabricated with different external diameters of the PZTs. Finally, the flow rate and pressure of the micropumps are measured, which are consistent with the vibrational results. Moreover, the maximum displacement is larger under a square-wave driving signal, followed by a sine-wave signal, and then a triangle-wave signal. For a PZT with an external diameter of $12$ mm, the maximum flow rate and pressure value are $150$~$upmu$l/min and $346$ Pa, respectively, under sine-wave driving at $100$ Vpp driving voltage.

A piezoelectric micro gas compressor with parallel-serial hybrid chambers

2021 ◽  
pp. 1045389X2110639
Author(s):  
Song Chen ◽  
Zhen He ◽  
Chaoping Qian ◽  
Jianping Li ◽  
Zhonghua Zhang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Maximum Flow ◽  
Stage I ◽  
Stage Ii ◽  
Driving Voltage ◽  
Driving Frequency ◽  
Output Pressure ◽  
New Ideas ◽  
Further Development ◽  
Large Flow

A piezoelectric micro gas compressor with parallel-serial hybrid chambers (PMGCPS) is presented, which consists of two compression stages of stage I and stage II. The stage I is composed of two piezoelectric driving units connected in parallel, while stage II is composed of a piezoelectric driving unit, forming an integral tower compression structure. Based on the tower compression structure, the PMGCPS owns the dual advantages of large flow rate and high output pressure. The prototype of PMGCPS is designed and manufactured. The driving frequency and voltage characteristics of PMGCPS are experimented. Under the driving frequency of 300 Hz and the driving voltage of 300 Vpp, the maximum flow rate and output pressure of PMGCPS is 795.6 mL/min and 13.4 kPa, respectively. PMGCPS provides new ideas for the further development of piezoelectric micro gas compressor.

Outcome of Buccal Mucosal Graft Urethroplasty in Long Segment Anterior Urethral Stricture

2020 ◽  
Vol 19 (2) ◽  
pp. 64-68
Author(s):  
Mrinmoy Biswas ◽  
Sudip Das Gupta ◽  
Mohammed Mizanur Rahman ◽  
Sharif Mohammad Wasimuddin
Keyword(s):  
Urethral Stricture ◽  
Flow Rate ◽  
Surgical Outcome ◽  
Simple Technique ◽  
Anterior Segment ◽  
Maximum Flow ◽  
Anastomotic Site ◽  
Buccal Mucosal Graft ◽  
Male Patients

Objective: To assess the success of BMG urethroplasty in long segment anterior urethral stricture. Method: From January 2014 to December 2015, twenty male patients with long anterior segment urethral stricture were managed by BMG urethroplasty. After voiding trial they were followed up at 3 month with Uroflowmetry, RGU & MCU and PVR measurement by USG. Patients were further followed up with Uroflowmetry and PVR at 6 months interval.Successful outcome was defined as normal voiding with a maximum flow rate >15ml /sec and PVR<50 ml with consideration of maximum one attempt of OIU after catheter removal. Results: Mean stricture length was 5.2 cm (range 3-9 cm) and mean follow-up was 15.55 months (range 6-23 months). Only two patients developed stricture at proximal anastomotic site during follow-up. One of them voided normally after single attempt of OIU. Other one required second attempt of OIU and was considered as failure (5%). Conclusion: BMG urethroplasty is a simple technique with good surgical outcome. Bangladesh Journal of Urology, Vol. 19, No. 2, July 2016 p.64-68

Research on an axial-mounted dual magnetostrictive material rods-based electro-hydrostatic actuator

2021 ◽  
pp. 1045389X2110145
Author(s):  
Yuchuan Zhu ◽  
Chang Liu ◽  
Yunze Song ◽  
Long Chen ◽  
Yulei Jiang ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Flow Rate ◽  
Flow Distribution ◽  
Maximum Flow ◽  
Magnetostrictive Material ◽  
Simulation Techniques ◽  
Motion State ◽  
New Type ◽  
Output Characteristics ◽  
Active Rectification

In this paper, an electro-hydrostatic actuator driven by dual axial-mounted magnetostrictive material rods-based pumps (MMPs) with a new type of active rectification valve is designed in the current study. Based on flow distribution of the active rectification valve and driving energy provided by two MMPs, the actuator can output continuous and bidirectional displacement. By establishing a mathematical model of the actuating system, using simulation techniques, the change rule of hydraulic cylinder’s motion state caused by different driving signals are studied and analyzed. Test equipment platform is constructed in the laboratory to test the output characteristics and confirm the feasibility of the new concept. The experimental results indicate that the maximum flow rate can reach approximately 2.7 L·min−1, while the operating frequency is 180 Hz.

Lichen sclerosis–induced long segment anterior urethral stricture: The early outcome of one-stage repair using dorsolateral onlay buccal mucosa graft

2021 ◽  
pp. 039156032110033
Author(s):  
Atef Fathi ◽  
Omar Mohamed ◽  
Osama Mahmoud ◽  
Gamal A Alsagheer ◽  
Ahmed M Reyad ◽  
...  
Keyword(s):  
Success Rate ◽  
Urethral Stricture ◽  
Flow Rate ◽  
Urine Volume ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
P Value ◽  
Onlay Graft ◽  
Voiding Symptoms ◽  
Stricture Recurrence

Background: Substitution urethroplasty using buccal mucosal grafts can be performed by several approaches including ventral onlay graft, dorsal onlay graft, or ventral urethrotomy with dorsal inlay graft. Our study aims to evaluate the surgical outcome of dorsolateral buccal mucosal graft for long segment anterior urethral stricture >6 cm in patients with Lichen sclerosus (LS). Methods: A retrospective study included patients who underwent repair for long segment anterior urethral stricture >6 cm due to LS between January 2013 and April 2019. All patients were followed-up at 3, 6, 9, and 12 months postoperatively and then yearly by clinical symptoms, uroflowmetry, and calculation of post-void residual urine volume. Retrograde urethrogram was requested for patients with voiding symptoms or decreased maximum flow rate. Stricture recurrence that required subsequent urethrotomy or urethroplasty was considered failure. The success rate and surgical complications were collected and analyzed. Results: Thirty patients were identified. The median age (range) was 39 (25–61) years and a median (range) stricture length was 8 (6–14) cm. Most of postoperative complications were of minor degree. The success rate at median follow-up of 15 (12–24) months was 86.5%. The median maximum flow rate increased significantly from 6 (2–11) ml/s preoperatively to 18 (range: 6–23) ml/s at the 6th month ( p value < 0.001). Conclusion: Dorsolateral buccal mucosal grafts urethroplasty for long anterior urethral stricture caused by LS has a high success rate and low risk of complications including stricture recurrence.

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