A STUDY OF FLUID-MEMBRANE INTERACTIONS THAT LIMIT THE OUTPUT OF PERISTALTIC MICROPUMPS

2011 ◽  
Vol 11 (02) ◽  
pp. 325-336 ◽  
Author(s):  
CHAN YOUNG PARK ◽  
MAIYA SHUR ◽  
C. FORBES DEWEY
Keyword(s):  
Fluid Flow ◽  
Numerical Model ◽  
Flow Rate ◽  
Middle Layer ◽  
Bottom Layer ◽  
Experimental Models ◽  
Hydrodynamic Performance ◽  
Fluid Membrane ◽  
Peristaltic Micropump ◽  
Relationship Of

In many microfluidic devices, fluid flow is generated using micropumps like peristaltic micropumps. However the hydrodynamic performance of peristaltic micropumps has not been fully understood and furthermore the effect of dynamic interaction of pumping membrane and fluid flow has not been studied yet. To fill this gap, we studied the hydrodynamic performance of a peristaltic micropump using a numerical model incorporating the fluid-solid interactions. The model consisted of 3 layers; the top layer was the flow channel of 10 μm high, the middle layer was the 5~30 μm thick pumping membrane and the bottom layer was the 3 or 5 pumping chambers. By applying a pumping sequence at a frequency between 16~166 Hz, we calculated flow rate for at least 4 cycles and used the fourth or fifth cycle to evaluate the flow rate per a cycle. We found that the numerical model closely replicated the frequency vs. flow rate relationship of a peristaltic micropump as shown earlier in experimental models. We further found that the flow rate of a peristaltic micropump could be improved by increasing the number of pumping chambers or the thickness of pumping membrane.

scholarly journals Numerical Modeling and Dynamic Analysis of a Wave-Powered Reverse-Osmosis System

2018 ◽  
Vol 6 (4) ◽  
pp. 132
Author(s):  
Yi-Hsiang Yu ◽  
Dale Jenne
Keyword(s):  
Numerical Model ◽  
Reverse Osmosis ◽  
Flow Rate ◽  
Wave Energy ◽  
Energy Resource ◽  
Diffraction Method ◽  
Hydrodynamic Performance ◽  
Water Model ◽  
Hydraulic Pressure ◽  
Water Production

A wave energy converter (WEC) system has the potential to convert the wave energy resource directly into the high-pressure flow that is needed by the desalination system to pump saltwater to the reverse-osmosis membrane and provide the required pressure level to generate freshwater. In this study, a wave-to-water numerical model was developed to investigate the potential use of a wave-powered desalination system (WPDS) for water production. The model was developed by coupling a time-domain radiation-and-diffraction method-based numerical tool (WEC-Sim) for predicting the hydrodynamic performance of WECs with a solution-diffusion model that was used to simulate the reverse-osmosis (RO) process. The objective of this research is to evaluate the WPDS dynamics and the overall efficiency of the system. To evaluate the feasibility of the WPDS, the wave-to-water numerical model was applied to simulate a desalination system that used an oscillating surge WEC device to pump seawater through the system. The hydrodynamics WEC-Sim simulation results for the oscillating surge WEC device were validated against existing experimental data. The RO simulation was verified by comparing the results to those from the Dow Chemical Company’s reverse osmosis system analysis (ROSA) model, which has been widely used to design and simulate RO systems. The wave-to-water model was then used to analyze the WPDS under a range of wave conditions and for a two-WECs-coupled RO system to evaluate the influence of pressure and flow rate fluctuation on the WPDS performance. The results show that the instantaneous energy fluctuation from waves has a significant influence on the responding hydraulic pressure and flow rate, as well as the recovery ratio and, ultimately, the water-production quality. Nevertheless, it is possible to reduce the hydraulic fluctuation for different sea states while maintaining a certain level of freshwater production, and a WEC array that produces water can be a viable, near-term solution to the nation’s water supply. A discussion on the dynamic impact of hydraulic fluctuation on the WPDS performance and potential options to reduce the fluctuation and their trade-offs is also presented.

scholarly journals Modeling of fiber bridging in fluid flow for well stimulation applications

2019 ◽  
Vol 17 (3) ◽  
pp. 671-686 ◽  
Author(s):  
Mehdi Ghommem ◽  
Mustapha Abbad ◽  
Gallyam Aidagulov ◽  
Steve Dyer ◽  
Dominic Brady
Keyword(s):  
Fluid Flow ◽  
Numerical Model ◽  
New Product Development ◽  
Flow Rate ◽  
Empirical Studies ◽  
Operating Conditions ◽  
Solid Particles ◽  
Fluid Viscosity ◽  
Design Guideline ◽  
Fiber Loading

AbstractAccurate acid placement constitutes a major concern in matrix stimulation because the acid tends to penetrate the zones of least resistance while leaving the low-permeability regions of the formation untreated. Degradable materials (fibers and solid particles) have recently shown a good capability as fluid diversion to overcome the issues related to matrix stimulation. Despite the success achieved in the recent acid stimulation jobs stemming from the use of some products that rely on fiber flocculation as the main diverting mechanism, it was observed that the volume of the base fluid and the loading of the particles are not optimized. The current industry lacks a scientific design guideline because the used methodology is based on experience or empirical studies in a particular area with a particular product. It is important then to understand the fundamentals of how acid diversion works in carbonates with different diverting mechanisms and diverters. Mathematical modeling and computer simulations are effective tools to develop this understanding and are efficiently applied to new product development, new applications of existing products or usage optimization. In this work, we develop a numerical model to study fiber dynamics in fluid flow. We employ a discrete element method in which the fibers are represented by multi-rigid-body systems of interconnected spheres. The discrete fiber model is coupled with a fluid flow solver to account for the inherent simultaneous interactions. The focus of the study is on the tendency for fibers to flocculate and bridge when interacting with suspending fluids and encountering restrictions that can be representative of fractures or wormholes in carbonates. The trends of the dynamic fiber behavior under various operating conditions including fiber loading, flow rate and fluid viscosity obtained from the numerical model show consistency with experimental observations. The present numerical investigation reveals that the bridging capability of the fiber–fluid system can be enhanced by increasing the fiber loading, selecting fibers with higher stiffness, reducing the injection flow rate, reducing the suspending fluid viscosity or increasing the attractive cohesive forces among fibers by using sticky fibers.

Computational Modelling of Fluid Flow in Radial Diffusers With Irregular Boundaries

2006 ◽  
Author(s):  
Viviana Cocco Mariani ◽  
Alvaro Toubes Prata
Keyword(s):  
Fluid Flow ◽  
Numerical Model ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Numerical Solutions ◽  
Computational Modelling ◽  
Reynolds Numbers ◽  
Valve Seat ◽  
Irregular Geometries

Radial diffusers are the basic geometry for the automatic valves in reciprocating hermetic compressors. In the present work numerical solutions for the laminar isocoric flow in radial diffusers are performed to investigate the influence of some geometry modifications on the mass flow, rate and on the resultant force on the valve. The numerical model was able to handle irregular geometries making use of a regular mesh, and was validated through comparisons with experiments. Results are presented in terms of the effective flow and force area of valves which are important efficiency parameters for the modelling and design of reciprocating hermetic compressors. The efficiency parameters are presented and explored in terms of small modification of the valve geometry, for Reynolds numbers varying from 1000 to 2500 and two values of the gap between valve reed and valve seat. The flow was significantly affected by the geometry modifications, indicating that with little effort the performance of automatic valves can be substantialy improved. For instance, with a small chamfer of 5° at the outlet of the valve feeding orifice, the effective force area was increased by 30 percent.

Application of Cross-correlation Analysis Method for Measurement of the Fluid Flow Rate Based on X-ray Radiation

2019 ◽  
Vol 11 (1) ◽  
pp. 01025-1-01025-5 ◽  
Author(s):  
N. A. Borodulya ◽  
◽  
R. O. Rezaev ◽  
S. G. Chistyakov ◽  
E. I. Smirnova ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Correlation Analysis ◽  
Flow Rate ◽  
Cross Correlation ◽  
Fluid Flow Rate ◽  
Analysis Method ◽  
X Ray ◽  
Cross Correlation Analysis ◽  
Correlation Analysis Method

Study of fluid flow through a channel deformed by piezoelement

2018 ◽  
Vol 13 (3) ◽  
pp. 1-10 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh Nasibullaeva ◽  
O.V. Darintsev
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Boundary Conditions ◽  
Flow Rate ◽  
Contact Surface ◽  
Piezoelectric Element ◽  
Neumann Boundary ◽  
Differential Pressure ◽  
Physical Parameters ◽  
Flow Through

The flow of a liquid through a tube deformed by a piezoelectric cell under a harmonic law is studied in this paper. Linear deformations are compared for the Dirichlet and Neumann boundary conditions on the contact surface of the tube and piezoelectric element. The flow of fluid through a deformed channel for two flow regimes is investigated: in a tube with one closed end due to deformation of the tube; for a tube with two open ends due to deformation of the tube and the differential pressure applied to the channel. The flow rate of the liquid is calculated as a function of the frequency of the deformations, the pressure drop and the physical parameters of the liquid.

scholarly journals High-Gain Vivaldi Antenna with Wide Bandwidth Characteristics for 5G Mobile and Ku-Band Radar Applications

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 667
Author(s):  
Raza Ullah ◽  
Sadiq Ullah ◽  
Farooq Faisal ◽  
Rizwan Ullah ◽  
Dong-you Choi ◽  
...  
Keyword(s):  
Mobile Communication ◽  
Middle Layer ◽  
Bottom Layer ◽  
High Gain ◽  
Mirror Image ◽  
Radar Applications ◽  
Vivaldi Antenna ◽  
5G Mobile Communication ◽  
Element Array ◽  
Ku Band

In this paper, antipodal Vivaldi antenna is designed for 5th generation (5G) mobile communication and Ku-band applications. The proposed designed has three layers. The upper layer consists of eight-element array of split-shaped leaf structures, which is fed by a 1-to-8 power divider network. Middle layer is a substrate made of Rogers 5880. The bottom layer consists of truncated ground and shorter mirror-image split leaf structures. The overall size of the designed antenna is confined significantly to 33.31 × 54.96 × 0.787 (volume in mm3), which is equivalent to 2λo× 3.3λo× 0.05λo (λo is free-space wavelength at 18 GHz). Proposed eight elements antenna is multi-band in nature covering Ku-bands (14.44–20.98 GHz), two millimeter wave (mmW) bands i.e., 24.34–29 GHz and 33–40 GHz, which are candidate frequency bands for 5G communications. The Ku-Band is suitable for radar applications. Proposed eight elements antenna is very efficient and has stable gain for 5G mobile communication and Ku-band applications. The simulation results are experimentally validated by testing the fabricated prototypes of the proposed design.

Relationship of inspiratory flow rate and volume on digit tip skin and ulnar artery vasoconstrictor responses in healthy adults

2005 ◽  
Vol 69 (1-2) ◽  
pp. 95-100 ◽  
Author(s):  
Einar Wilder-Smith ◽  
Linda Liu ◽  
Khin Thein Ma Ma ◽  
Benjamin K.C. Ong
Keyword(s):  
Flow Rate ◽  
Ulnar Artery ◽  
Inspiratory Flow ◽  
Healthy Adults ◽  
Inspiratory Flow Rate ◽  
Relationship Of

Flow Features Analysis of Throttle Notches of Proportional Direct Valve

2011 ◽  
Vol 189-193 ◽  
pp. 2285-2288
Author(s):  
Wen Hua Jia ◽  
Chen Bo Yin ◽  
Guo Jin Jiang
Keyword(s):  
Fluid Flow ◽  
Dynamic Behavior ◽  
Flow Rate ◽  
Discharge Coefficient ◽  
3D Models ◽  
Operating Conditions ◽  
Flow Models ◽  
Flow Features ◽  
Rate Discharge ◽  
Spool Valve

Flow features, specially, flow rate, discharge coefficient and efflux angle under different operating conditions are numerically simulated, and the effects of shapes and the number of notches on them are analyzed. To simulate flow features, 3D models are developed as commercially available fluid flow models. Most construction machineries in different conditions require different actions. Thus, in order to be capable of different actions and exhibit good dynamic behavior, flow features should be achieved in designing an optimized proportional directional spool valve.

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