Simulation and Experimental Study of a Porous Electroosmotic Pump

2011 ◽  
Vol 483 ◽  
pp. 320-326 ◽  
Author(s):  
Zhou Ling ◽  
Tao Yang ◽  
Fan Chao Meng ◽  
Lin Yi ◽  
Xiang Xian Zhang
Keyword(s):  
Porous Media ◽  
Flow Rate ◽  
Pore Diameter ◽  
Maximum Flow ◽  
Joule Heat ◽  
Maximum Pressure ◽  
Electrical Field ◽  
Electroosmotic Pump ◽  
The Mathematical Model ◽  
Truncated Gaussian

Aiming at the coupling problems of electrical field and flow field in porous media microchannels, the mathematical model of electroosmotic(EO) flow is built. For a single microchannel, the influence of voltage on velocity and joule heat is analyzed by using CoventorWare. Numerical analysis shows that the velocity is proportional to the voltage and the joule heat is small and negligible. For the porous media, the flow rate is investigated by truncated Gaussian distribution of pore diameter. The electroosmotic microporous pump is fabricated, and the experimental results indicate that the maximum flow rate of porous media micropump is 16.89ml/min and the maximum pressure is 120.1kPa.

Directional Pumping Performance of an Electrostatic Checkerboard Microvalve

2006 ◽  
Author(s):  
Hanseup Kim ◽  
Aaron A. Astle ◽  
Luis P. Bernal ◽  
Khalil Najafi ◽  
Peter D. Washabaugh
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Maximum Flow ◽  
Pressure Differential ◽  
Oscillatory Motion ◽  
Sinusoidal Signal ◽  
Maximum Pressure ◽  
Experimental Characterization ◽  
Gas Pumping

This paper reports experimental characterization of directional gas pumping generated by MEMS-fabricated checkerboard-type electrostatic microvalves. It is found that the oscillatory motion of the checkerboard microvalve membrane provides both the pumping and valve functions of a pump, namely: 1) to cause the volume displacement and, thus, compression and transfer of gas, and 2) to direct gas flow in one direction by closing and opening air paths in the proper sequence. Here, we describe the microvalve-only design, and report the pumping performance producing a maximum flow rate of 1.8 sccm and a maximum pressure differential of 3.0 kPa for five microvalves driven simultaneously with a sinusoidal signal of ± 100V amplitude at 5.5 kHz.

Effect of shielding gas flow rate on arc behaviors in GMAW with single cable-typed wire

2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040059
Author(s):  
Qingxian Hu ◽  
Lei Zhang ◽  
Juan Pu ◽  
Caichen Zhu
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Maximum Velocity ◽  
Maximum Flow ◽  
Maximum Pressure ◽  
Arc Plasma ◽  
Shielding Gas ◽  
Gas Flow Rate

A three-dimensional numerical model of arc in gas metal arc welding (GMAW) with single cable-typed wire was established based on the theory of arc physics. The influences of different shielding gas flow rates on the features of temperature field, velocity field and pressure field were investigated. The results showed that the maximum velocity of arc plasma along radial direction and the arc pressure on the surface of workpieces were increased obviously with the increase of the shielding gas flow rate, while the arc temperature was changed little. This phenomenon was mainly attributed to the increasing collisions between arc plasmas and the self-rotation action of cable-typed wires. The arc temperature at the tip of the cable-typed wire reached the maximum. The maximum flow velocity of arc plasma was located at the tip of wire (2–8 mm). The arc pressures in the central axis reached the maximum pressure. The simulation results were in agreement with the experimental results.

scholarly journals Simulation of a Chain of Collapsible Contracting Lymphangions With Progressive Valve Closure

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
C. D. Bertram ◽  
C. Macaskill ◽  
J. E. Moore
Keyword(s):  
Flow Rate ◽  
Flow Direction ◽  
Maximum Flow ◽  
Transmural Pressure ◽  
Maximum Flow Rate ◽  
Smooth Transition ◽  
Maximum Pressure ◽  
Mean Flow ◽  
Forward Flow ◽  
In Series

The aim of this investigation was to achieve the first step toward a comprehensive model of the lymphatic system. A numerical model has been constructed of a lymphatic vessel, consisting of a short series chain of contractile segments (lymphangions) and of intersegmental valves. The changing diameter of a segment governs the difference between the flows through inlet and outlet valves and is itself governed by a balance between transmural pressure and passive and active wall properties. The compliance of segments is maximal at intermediate diameters and decreases when the segments are subject to greatly positive or negative transmural pressure. Fluid flow is the result of time-varying active contraction causing diameter to reduce and is limited by segmental viscous and valvular resistance. The valves effect a smooth transition from low forward-flow resistance to high backflow resistance. Contraction occurs sequentially in successive lymphangions in the forward-flow direction. The behavior of chains of one to five lymphangions was investigated by means of pump function curves, with variation of valve opening parameters, maximum contractility, lymphangion size gradation, number of lymphangions, and phase delay between adjacent lymphangion contractions. The model was reasonably robust numerically, with mean flow-rate generally reducing as adverse pressure was increased. Sequential contraction was found to be much more efficient than synchronized contraction. At the highest adverse pressures, pumping failed by one of two mechanisms, depending on parameter settings: either mean leakback flow exceeded forward pumping or contraction failed to open the lymphangion outlet valve. Maximum pressure and maximum flow-rate were both sensitive to the contractile state; maximum pressure was also determined by the number of lymphangions in series. Maximum flow-rate was highly sensitive to the transmural pressure experienced by the most upstream lymphangions, suggesting that many feeding lymphatics would be needed to supply one downstream lymphangion chain pumping at optimal transmural pressure.

Design and Analysis of a Thin Film Permanent Magnet Actuated Micro Pump

2013 ◽  
Vol 7 (2) ◽  
pp. 196-204 ◽  
Author(s):  
Chao Zhi ◽  
◽  
Tadahiko Shinshi ◽  
Minoru Uehara ◽  
Keyword(s):  
Thin Film ◽  
Permanent Magnet ◽  
Flow Rate ◽  
Maximum Flow ◽  
High Flow ◽  
Deformation Analysis ◽  
Maximum Pressure ◽  
Large Deformation Analysis ◽  
Micro Pump ◽  
Displacement Measurements

In this paper we present the design, analysis and an experimental evaluation of a micro pump utilizing a 20 µm thick, 3 mm diameter Thin Film Permanent Magnet (TFPM). The pump includes an electromagnet that uses a magnetic closed circuit. The design of the electromagnet was optimized and was theoretically explained. A PolyDiMethylSiloxane (PDMS) diaphragm with a thickness of approximately 80 µm was used in the pump. The electromagnetic force on the diaphragmwas calculated using a finite elementmethod. Large deformation analysis was used to calculate the displacement of the diaphragm. The force and displacement measurements agreed well with those calculated by simulation. The performance of the fabricated pump was also evaluated. During pumping, the displacement of the diaphragm reached 500 µm, which is the same as the height of the chamber. Furthermore, because of the large displacement, the pump is bubble tolerant and self-priming. A maximum flow rate of 50 µL/min and a maximum pressure of 110 Pa were achieved. A square wave input signal was demonstrated to be more effective than a sinusoidal signal in generating a high flow rate.

Development of a Mini Liquid Cooling System for High Heat Flux Electronic Devices

2009 ◽  
Author(s):  
Chien-Yuh Yang ◽  
Chun-Ta Yeh ◽  
Kou-Chung Huang ◽  
Shao-Nong Tsai
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Maximum Flow ◽  
Maximum Pressure ◽  
High Heat Flux ◽  
Cold Plate ◽  
Liquid Cooling ◽  
Commercial Products ◽  
Micro Pump ◽  
Liquid Cooling System

The size of the most of the current commercialized liquid cooling systems is apparently too large to be easily adapted in a notebook or a mini size desk top computer. This study incorporated the authors’ previous micro heat exchanger design with an extra slim pump concept proposed by a local manufacturer to develop a high performance miniature liquid cooling system. An integrated pump and cold plate assembly was also developed for further reducing the overall size of the system. In comparing to the commercial products, the test results show that the micro pump provides a higher maximum pressure head and maximum flow rate performance. The cold plate has the lowest thermal resistance at moderate and high flow rate region. And the performed of the entire liquid system is similar to that of the recently announced product. It is emphasized that the size of the present developed cold plate, pump and liquid cooling system is much smaller than that of all commercial products.

EXPERIMENTAL STUDY ON BASIC PERFORMANCE OF ELECTROOSMOTIC PUMP WITH ION EXCHANGING POROUS GLASS SLIT

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2627-2632 ◽  
Author(s):  
HO LEE ◽  
GYU MAN KIM ◽  
CHOON YOUNG LEE ◽  
CHEOL WOO PARK ◽  
DAE JOONG KIM
Keyword(s):  
Drug Delivery ◽  
Experimental Study ◽  
Flow Rate ◽  
Maximum Flow ◽  
Precise Control ◽  
Electroosmotic Pump ◽  
Optimal Drug ◽  
Basic Performance ◽  
Electroosmotic Pumping ◽  
Performance Results

The basic concept and preliminary performance results of a miniaturized electroosmotic pump with diaphragms were included in the present study. The separation of an electroosmotic pumping liquid from a drug using diaphragms is mainly to have a freedom in choosing an electroosmotic pumping liquid and to achieve the optimal drug delivery with its preferable precise control. As a result, the maximum flow rate and current increased linearly according to the increment of applied voltage that is electric potential.

Optimization of High Flow Rate Nanoporous Electroosmotic Pump

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Y. Berrouche ◽  
Y. Avenas ◽  
C. Schaeffer ◽  
P. Wang ◽  
H.-C. Chang
Keyword(s):  
Flow Rate ◽  
Pore Radius ◽  
Debye Length ◽  
Maximum Flow ◽  
High Flow ◽  
Nanoporous Silica ◽  
Thermodynamic Efficiency ◽  
Hydraulic Circuit ◽  
Electroosmotic Pump ◽  
Disk Substrate

We present a theory for optimizing the thermodynamic efficiency of an electroosmotic (EO) pump with a large surface area highly charged nanoporous silica disk substrate. It was found that the optimum thermodynamic efficiency depends on the temperature, the silica zeta potential, the viscosity, the permittivity, the ion valency, the tortuosity of the nanoporous silica but mainly the effective normalized pore radius of the substrate scaled with respect to the Debye length. Using de-ionized water as the pumping liquid, the optimized EO pump generates a maximum flow rate of 13.6ml∕min at a pressure of 2kPa under an applied voltage of 150V. The power consumed by the pump is less than 0. 4W. The EO pump was designed to eliminate any bubble in the hydraulic circuit such that the pump can be operated continuously without significant degradation in the performance.

Propose and Characteristics Study of a New Actuation Method for Micropumps, Using Membrane Buckling

2005 ◽  
Author(s):  
Mohammad H. Saghafi ◽  
Mohammad T. Ahmadian ◽  
Hadi Salehi ◽  
R. Monazami ◽  
Azad Q. Zade
Keyword(s):  
Flow Rate ◽  
Outer Space ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Maximum Pressure ◽  
High Frequencies ◽  
Actuation System ◽  
Good Ability ◽  
Analytical Proof ◽  
Mechanical Actuation

In this paper, we present a novel idea on actuation system in micropumps. The prominent goal of this paper is to propose and prove a mechanical actuation system which works in high frequency and has good ability in producing flow and pressure in micro actuation system. As like as other common micropumps, the proposed scheme is consisted of two check valves and an actuation space. The actuation space includes a volume of liquid in a chamber and a cylindrical membrane as the actuator. The main aspect of this idea is employment of buckling as a consequence of incensement of its internal pressure caused by temperature rising in the membrane. Rise of temperature is done by passing a controllable current through the membrane and it looses its temperature to its outer space in the chamber. Frequency and amperage of the current are the elements identifying the temperatures membrane vacillates between them. Meanwhile, a nice idea is setting these values in such a way that minimum temperature of the membrane becomes equal to the temperature which membrane starts buckling at. Thermal, elastic and thermoelastic equations of the membrane and fluids dynamic equations is obtained and studied. Using these equations, the validity of the scheme is proved by showing its ability of getting and loosing temperature and also fatigue resistance of the membrane, in high frequencies. The analytical proof is done for a specific design. In the proposed design, Aluminum 1100 is adopted as membrane material and thickness and radius of the membrane are 1 μm and 100 μm, respectively. Maximum flow rate and frequency of the system according to highest temperature of the membrane are depicted in diagrams. According to this design, maximum flow rate in rational frequency and amperage of the current is 8.25 μL/min. Maximum pressure in that design is 3.5Kpa.

A New Monolithic Electrokinetic Pump With Bubble-Less Design

2005 ◽  
Author(s):  
Ping Wang ◽  
Zilin Chen ◽  
Hsueh-Chia Chang
Keyword(s):  
Flow Rate ◽  
Sol Gel ◽  
Maximum Flow ◽  
Liquid Solution ◽  
Fused Silica ◽  
Silica Matrix ◽  
Maximum Pressure ◽  
Micro Pump ◽  
Micro Total Analysis Systems ◽  
Fused Silica Capillary

An electrokinetic micro-pump fabricated by a sol-gel process has been designed which can be used as a robust fluid-driving unit on a chip-scale analytical system. An overall monolithic silica matrix with morphology of micron-scaled through pores was formed within 100-μm inner diameter fused silica capillary. This pump utilizes electroosmotic flow to propel liquid solution with no moving parts. The Nafion® house design in the cathode chamber separates the electrolytic bubble interference from flow channels. The maximum flow rate and maximum pressure generated by the pump are 3.0 μL/min and 3.5 atm, respectively, at 6 kV. The flow rate can be controlled in the range 200 nL-3.0 μL/min by adjusting applied electric filed. As the monolith is silica-based, this pump can be used for a variety of fluids, especially for organic solvents such as acetonitrile and methanol, without swelling and shrinking problems. These results indicate that the pump can provide sufficient pressure and flow for micro-total-analysis systems (μTAS).

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

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