scholarly journals Characterisation of Permeability around a 90° Corner

2000 ◽  
Vol 9 (1) ◽  
pp. 096369350000900 ◽  
Author(s):  
Nicolas Laval ◽  
E. Murat Sozer ◽  
Suresh G. Advani
Keyword(s):  
Flow Direction ◽  
Time Derivative ◽  
Constant Flow ◽  
Bend Section ◽  
One Dimensional ◽  
Constant Flow Rate ◽  
Mould Filling ◽  
Order Of Magnitude ◽  
Resistive Model ◽  
Complicated Geometries

One-dimensional mould filling experiments were done in L- and T-shaped moulds with constant flow rate injection, and the pressure history was measured. Transient relationship between the preform permeability along the flow direction and the time derivative of pressure was used to measure the permeability. It was found that the resistance to flow around the bend increased by an order of magnitude within the boundary layer of the 90° bend. A simple resistive model with three different permeabilities could be used to describe the decrease in the permeability around the bend using a corner model and hence one could predict the permeability in the bend region. While considering numerical simulations of complicated geometries with bends, one should account for the variation in the bend section to capture the physics of flow in such structures.

Unsaturated flow characteristics in dual-scale fibre fabrics at one-dimensional constant flow rate

2016 ◽  
Vol 23 (6) ◽  
pp. 617-624
Author(s):  
Yan Shilin ◽  
Yan Fei ◽  
Li Dequan ◽  
Li Yongjing
Keyword(s):  
Flow Rate ◽  
Unsaturated Flow ◽  
Flow Characteristics ◽  
Constant Flow ◽  
One Dimensional ◽  
Constant Flow Rate ◽  
Liquid Composite Moulding ◽  
Mould Filling ◽  
Set Up ◽  
Dual Scale

AbstractFibre fabrics in liquid composite moulding can be considered as dual-scale porous media. In different gap scales, an unsaturated flow is produced during the mould filling process. This particular flow behaviour deviates from the traditional Darcy’s law, which is used to calculate the filling pressure and will cause errors. To prove the mechanism of this unsaturated flow, an experimental device was set up with a one-dimensional constant flow rate. The influencing factors, such as injected media, flow velocity and fibre fabric, were investigated in this study. Based on the experimental data, several useful conclusions were drawn, providing good references for optimising the process parameters and controlling the product quality.

Experimental Study on Planar Unidirectional Permeability of Glass Fiber Preforms at Constant Flow Rate

2010 ◽  
Vol 154-155 ◽  
pp. 494-497
Author(s):  
Shi Lin Yan ◽  
Fei Yan ◽  
Zhong Qi Qiu
Keyword(s):  
Experimental Study ◽  
Flow Rate ◽  
Resin Flow ◽  
Constant Flow ◽  
Flow Rates ◽  
One Dimensional ◽  
Constant Flow Rate ◽  
Transfer Molding ◽  
The One ◽  
Fiber Preforms

During the resin flow of Resin Transfer Molding, the permeability of fiber performs is an important parameter, which reflects the interaction between the resin and fiber. In this paper the Darcy’s law was used as the fundamentals to determine the permeability of fiber performs, an experiment installation was designed, and do some experimental study on the one-dimensional permeability of resin in the multilayer fibrous plaids at a constant flow rate. The installation was designed base on condition of different flow rates and different fiber volumes (or porosity), and compared the results of the permeability of different flow rates. Then analyzed the results, and some content conclusions were obtained.

An anti-settling sample delivery instrument for serial femtosecond crystallography

2012 ◽  
Vol 45 (4) ◽  
pp. 674-678 ◽  
Author(s):  
Lukas Lomb ◽  
Jan Steinbrener ◽  
Sadia Bari ◽  
Daniel Beisel ◽  
Daniel Berndt ◽  
...  
Keyword(s):  
Constant Flow ◽  
Syringe Pump ◽  
Experimental Conditions ◽  
Flow Rates ◽  
X Ray ◽  
Constant Flow Rate ◽  
Significant Impairment ◽  
Working Principle ◽  
After Hours ◽  
Serial Femtosecond Crystallography

Serial femtosecond crystallography (SFX) using X-ray free-electron laser (FEL) sources has the potential to determine the structures of macromolecules beyond the limitation of radiation damage and without the need for crystals of sufficient size for conventional crystallography. In SFX, a liquid microjet is used to inject randomly oriented crystals suspended in their storage solution into the FEL beam. Settling of crystals in the reservoir prior to the injection has been found to complicate the data collection. This article details the development of an anti-settling sample delivery instrument based on a rotating syringe pump, capable of producing flow rates and liquid pressures necessary for the operation of the injector. The device has been used successfully with crystals of different proteins, with crystal sizes smaller than 20 µm. Even after hours of continuous operation, no significant impairment of the experiments due to sample settling was observed. This article describes the working principle of the instrument and sets it in context with regard to the experimental conditions used for SFX. Hit rates for longer measuring periods are compared with and without the instrument operating. Two versions of the instrument have been developed, which both deliver sample at a constant flow rate but which differ in their minimum liquid flow rates and maximum pressures.

Pumpless Fuel Supply Using Pressurized Fuel Regulated by Autonomous Flow-Rate Regulation Valves

2012 ◽  
Vol 9 (3) ◽  
Author(s):  
Il Doh ◽  
Young-Ho Cho
Keyword(s):  
Fuel Cells ◽  
Flow Rate ◽  
Electrical Power ◽  
Initial Pressure ◽  
Flow Regulation ◽  
Present System ◽  
Constant Flow ◽  
Constant Flow Rate ◽  
Fuel Supply ◽  
Fuel Flow

A pumpless fuel supply using pressurized fuel with autonomous flow regulation valves is presented. Since micropumps and their control circuitry consume a portion of the electrical power generated in fuel cells, fuel supply without micropumps makes it possible to provide more efficient and inexpensive fuel cells than conventional ones. The flow regulation valves in the present system maintain the constant fuel flow rate from the pressurized fuel chamber even though the fuel pressure decreases. They autonomously adjust fluidic resistance of the channel according to fuel pressure so as to maintain constant flow rate. Compared to previous pumpless fuel supply methods, the present method offers more uniform fuel flow without any fluctuation using a simple structure. The prototypes were fabricated by a polymer micromolding process. In the experimental study using the pressurized deionized water, prototypes with pressure regulation valves showed constant flow rate of 5.38 ± 0.52 μl/s over 80 min and 5.89 ± 0.62 μl/s over 134 min, for the initial pressure in the fuel chamber of 50 and 100 kPa, respectively, while the other prototypes having the same fluidic geometry without flow regulation valves showed higher and gradually decreasing flow rate. The present pumpless fuel supply method providing constant flow rate with autonomous valve operation will be beneficial for the development of next-generation fuel cells.

scholarly journals Fabrication of a Urea Biosensor for Real-Time Dynamic Fluid Measurement

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2607 ◽  
Author(s):  
Kyunghee Kim ◽  
Jeongeun Lee ◽  
Bo Moon ◽  
Ye Seo ◽  
Chan Park ◽  
...  
Keyword(s):  
Real Time ◽  
Urea Concentration ◽  
Electrochemical Sensing ◽  
Constant Flow ◽  
Flow Conditions ◽  
Time Dynamic ◽  
Constant Flow Rate ◽  
Linear Current ◽  
Clinically Significant ◽  
Significant Concentration

In this study, a portable urea sensor that monitors the urea concentration in flow conditions was fabricated. We propose an electrochemical sensor that continually measures the urea concentration of samples flowing through it at a constant flow rate in real time. For the electrochemical sensing, a porous silk fibroin membrane with immobilized urease was mounted in a polydimethylsiloxane (PDMS) sensor housing. The fabricated urea sensor elicited linear current–concentration characteristics in the clinically significant concentration range (0.1–20 mM) based on peritoneal dialysis. The sensor maintained the linear current–concentration characteristics during operation in flow conditions.

Transient Analysis of In-Plane and Through Thickness Flow During VARTM in the Presence of HPM

2014 ◽  
Author(s):  
Debabrata Adhikari ◽  
Suhasini Gururaja
Keyword(s):  
Transient Analysis ◽  
Flow Model ◽  
Resin Flow ◽  
Constant Flow ◽  
High Permeability ◽  
Coupled Flow ◽  
Resin Infusion ◽  
Plane Flow ◽  
Constant Flow Rate ◽  
Vartm Process

Modeling resin flow for a Vacuum Assisted Resin Transfer Molding (VARTM) process involves developing an approach for coupled flow-compaction, porosity-permeability, resin-cure and stress-development phenomena. In the present work, a modified transient incompressible resin flow model has been developed for VARTM without considering the constant flow rate assumption. The use of High Permeability Medium (HPM) during VARTM results in a through-thickness flow in addition to in-plane flow developing due to the pressure gradient. Results have been validated with existing literature. Fill time comparisons for with and without HPM cases have been presented. Some preliminary results of 2D plane flow have also been obtained which show promise in replicating the physics of vacuum assisted resin infusion composite manufacturing process.

scholarly journals Dissociation and recombination in the electrolyte flow model

2021 ◽  
Vol 2090 (1) ◽  
pp. 012076
Author(s):  
A Shobukhov ◽  
H Koibuchi
Keyword(s):  
Flow Model ◽  
Numerical Solutions ◽  
Stable Equilibrium ◽  
Steady State Solution ◽  
System Of Equations ◽  
Constant Flow ◽  
Dimensional Model ◽  
Electrolyte Flow ◽  
One Dimensional ◽  
Dilute Aqueous Solution

Abstract We propose a one-dimensional model for the dilute aqueous solution of NaCl which is treated as an incompressible fluid placed in the external electric field. This model is based on the Poisson-Nernst-Planck system of equations, which also contains the constant flow velocity as a parameter and considers the dissociation and the recombination of ions. We study the steady-state solution analytically and prove that it is a stable equilibrium. Analyzing the numerical solutions, we demonstrate the importance of dissociation and recombination for the physical meaningfulness of the model.

scholarly journals Purpose of the housing double stage polypropylene-carbon cartridges filters usage in bath gray water treatment

2020 ◽  
Vol 29 (2) ◽  
pp. 244-258
Author(s):  
Maciej Malarski ◽  
Marek Kalenik
Keyword(s):  
Human Life ◽  
Quality Parameters ◽  
Constant Flow ◽  
Slight Improvement ◽  
Constant Flow Rate ◽  
Gray Water ◽  
Filtration System ◽  
Pollution Indicator ◽  
The Impact ◽  
Carbon Filter

Bath gray water organoleptically did not appear to be significantly contaminated liquid. However, in order to re-use them, they need proper treatment. When recirculated in a household, they cannot pose a threat to human life. Based on their appearance, it seems that the solution to the problem is the use of cartridges filter. The article presents the results of the filtration of gray water from the bath through the filtration system with a housing double stage polypropylene-carbon filter FCCA-STO and to determine the impact of individual filter layers on wastewater treatment, tests were carried out on a single polypropylene FCPS10 and carbon FCCA filtration cartridge. The aim of the study was to determine the suitability of the selected housing filter cartridges for the treatment of bathing gray water for their reuse. For the tests were used natural bathing gray water from a two-family building inhabited by seven people. Wastewater were fed to the filter with a constant flow rate of 0.1 dm3·s–1. The assessment of the work of the filters based on parameters such as: COD, BOD5, suspension, dry residue, decay and turbidity. The conducted tests have shown a slight improvement in most of the quality parameters of gray water after filtration through selected housing cartridge filters. Only for turbidity, the reduction in the value of the pollution indicator was noticeable. The cartridge fi lters used in tests, acted like ordinary mechanical filtration cartridges. For the considered gray water, the use of analyzed cartridge fi lters can only be used for their initial purifi cation.

scholarly journals Feedback stabilization of one-dimensional parabolic systems related to formations

2015 ◽  
Vol 63 (1) ◽  
pp. 295-303
Author(s):  
H. Sano
Keyword(s):  
Finite Dimension ◽  
Time Derivative ◽  
Parabolic Systems ◽  
Feedback Stabilization ◽  
Boundary Values ◽  
One Dimensional ◽  
Finite Dimensional ◽  
Neumann Type ◽  
Sturm Liouville ◽  
Output Operator

Abstract This paper is concerned with the problem of stabilizing one-dimensional parabolic systems related to formations by using finitedimensional controllers of a modal type. The parabolic system is described by a Sturm-Liouville operator, and the boundary condition is different from any of Dirichlet type, Neumann type, and Robin type, since it contains the time derivative of boundary values. In this paper, it is shown that the system is formulated as an evolution equation with unbounded output operator in a Hilbert space, and further that it is stabilized by using an RMF (residual mode filter)-based controller which is of finite-dimension. A numerical simulation result is also given to demonstrate the validity of the finite-dimensional controller

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