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

Author(s):  
Debabrata Adhikari ◽  
Suhasini Gururaja

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.

2010 ◽  
Vol 154-155 ◽  
pp. 494-497
Author(s):  
Shi Lin Yan ◽  
Fei Yan ◽  
Zhong Qi Qiu

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.


2012 ◽  
Vol 45 (4) ◽  
pp. 674-678 ◽  
Author(s):  
Lukas Lomb ◽  
Jan Steinbrener ◽  
Sadia Bari ◽  
Daniel Beisel ◽  
Daniel Berndt ◽  
...  

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.


2012 ◽  
Vol 9 (3) ◽  
Author(s):  
Il Doh ◽  
Young-Ho Cho

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.


Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2607 ◽  
Author(s):  
Kyunghee Kim ◽  
Jeongeun Lee ◽  
Bo Moon ◽  
Ye Seo ◽  
Chan Park ◽  
...  

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.


2021 ◽  
Vol 2090 (1) ◽  
pp. 012076
Author(s):  
A Shobukhov ◽  
H Koibuchi

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.


2020 ◽  
Vol 29 (2) ◽  
pp. 244-258
Author(s):  
Maciej Malarski ◽  
Marek Kalenik

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.


2016 ◽  
Vol 50 (29) ◽  
pp. 4171-4186 ◽  
Author(s):  
Bo Yang ◽  
Qian Tang ◽  
Shilong Wang ◽  
Tianguo Jin ◽  
Fengyang Bi

Resin infusion (RI) process has been widely used for manufacturing composite parts. The variation of preform thickness brings great difficulty to the three-dimensional simulation of the filling stage. To accurately simulate the preform thickness change and resin flow during resin infusion, precise preform compaction models and dynamically changing geometry models need to be adopted. At present, resin flow is usually considered as two-dimensional and simple compaction models are employed to simplify the simulation, which degrades the prediction accuracy seriously. In this paper, general equations to describe the resin flow in the changing thickness cavity are developed, and the viscoelastic model is adopted which can fully express the dynamic characteristics of the preform compaction. To avoid solving the coupled resin flow/preform deformation equations directly, the volume of fluid method and the dynamic mesh model are employed to implement the tracking of the flow front and updating of cavity geometry model. The resin storage and release induced by porosity variations are adjusted by a master-slave element method to ensure mass conservation. Two simulation examples are carried out to demonstrate the capability of the above approach. The applicability of the approach on arbitrary complex domains and sequential injection strategy is also verified.


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