scholarly journals Monitoring the Capillary Jet Breakage by Vibration Using a Fast-Video Camera

2021 ◽  
Vol 11 (21) ◽  
pp. 10222
Author(s):  
Marcella Chalella Mazzocato ◽  
Sylvie Chevallier ◽  
Carmen S. Fávaro-Trindade ◽  
Denis Poncelet
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Video Camera ◽  
Solution Concentration ◽  
Low Flow ◽  
High Speed Camera ◽  
Optimum Conditions ◽  
Present Contribution ◽  
Simple Method ◽  
Alginate Solution

The production of beads by simple extrusion dropwise of an alginate solution in a calcium bath is a simple method. It may be done at room temperature without any toxic compound. However, simple extrusion drop by drop from a needle may result in large capsules and a low flow rate. The solution must be extruded as a jet to get a smaller size and higher flow rate, which breaks into droplets either by vibration or a cutting tool. The present contribution reports jet breakage observations into droplets under vibration by extruding an alginate solution varying some parameters during the study. The droplet formation was observed using a high-speed camera, and images were analyzed. The size, length before breakage, and droplet velocity were obtained by examining 50 droplets, and experiments were repeated three times. The high-speed camera allowed us to observe more precisely the capillary jet breakage. The study showed the importance of selecting a well-designed vibrating system, presented data while varying nozzle size, frequency, and flow rate to get optimum breakage keeping across all the same alginate solution. Further experiments would be interesting, modify the extruded solution concentration and composition, and find a precise criterion to identify optimum conditions.

Experimental study on the effect of pressure and flow rate on cavitation in a poppet throttle valve

2019 ◽  
Vol 72 (5) ◽  
pp. 629-636
Author(s):  
Jian Zhang ◽  
Tingting Luo
Keyword(s):  
Flow Rate ◽  
Pressure Difference ◽  
High Speed ◽  
High Speed Camera ◽  
Experimental Conditions ◽  
Content Type ◽  
Experimental Support ◽  
Throttle Valve ◽  
Set Up

Purpose The purpose of this paper is to study the variation of cavitation scale with pressure and flow in poppet throttle valve, to obtain the cavitation scale under pressure and flow conditions and to provide experimental support for the research of suppressing throttle valve cavitation and cavitation theory. Design/methodology/approach A hydraulic cavitation platform was set up, a valve was manufactured with highly transparent PMMA material and a high-speed camera was used to observe the change in cavitation scale. Findings Through experiments, it is found that the pressure difference between inlet and outlet of throttle valve affects the cavitation scale, and the more the pressure difference is, the easier the cavitation will be formed. Under the condition of small pressure difference, the cavitation is not obvious and reducing the pressure difference can effectively suppress the cavitation; the flow rate also affects the cavitation scale, the smaller the flow rate, the more difficult the cavitation will be formed and the lower the flow rate, the more the cavitation will be suppressed. Research limitations/implications Because of the magnification factor of the high-speed camera lens, the morphology of smaller bubbles cannot be observed in this study, and the experimental conditions need to be improved in the follow-up study. Originality/value This study can provide experimental support for the study of throttle valve cavitation suppression methods and cavitation theory.

Response surface methodology optimization of electrospinning process parameters to fabricate aligned polyvinyl butyral nanofibers for interlaminar toughening of phenolic-based composite laminates

2018 ◽  
Vol 49 (7) ◽  
pp. 858-874 ◽  
Author(s):  
Parvaneh Kheirkhah Barzoki ◽  
Masoud Latifi ◽  
Amir Masoud Rezadoust
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Composite Laminates ◽  
High Speed ◽  
Polyvinyl Butyral ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Optimum Conditions ◽  
Nanofiber Diameter ◽  
Mode Ii Fracture Toughness

In this study and for the first time, aligned nanofibers were produced from low molecular weight polyvinyl butyral. Using response surface methodology, the preparation condition of aligned nanofiber was optimized in terms of nanofiber diameter and its structural stability. Central composite design as a response surface methodology was employed and the effects of process variables and their influence on nanofiber diameter were investigated. Based on a statistical analysis, the use of a model, which was used to determine the nanofiber diameter, proved to be successful because of its low probability value (0.0073) and high correlation coefficient (0.9619). A high-speed cylinder collector was used to fabricate aligned polyvinyl butyral nanofibers. The optimum conditions of 17.5 kV voltage, 10 cm collector distance, 13% solution concentration, and 2100 r/min rotational speed were obtained from experiments. The least diameter of 158.6 nm along with a stable structure was determined for polyvinyl butyral nanofiber prepared under the optimum conditions. An aligned polyvinyl butyral nanoweb was applied on the mid-layer of glass-phenolic laminated composites as an interlaminar reinforcement. The fracture behavior of the laminates was determined by end-notched flexure tests. Excellent toughening property which was observed for the aligned polyvinyl butyral nanofibers caused the mode-II fracture toughness and its maximum force to increase by 25.2 and 40.8%, respectively.

A Study of Optimum Conditions for Electrospinning Cellulose Acetate Nanofibers in Trifluoroacetic Acid Solvent

2013 ◽  
Vol 750-752 ◽  
pp. 323-327
Author(s):  
Edison Omollo ◽  
Chu Yang Zhang ◽  
Wan Jun Liu ◽  
Ncube Sizo
Keyword(s):  
Cellulose Acetate ◽  
Flow Rate ◽  
Trifluoroacetic Acid ◽  
Low Flow ◽  
Optimum Conditions ◽  
Flow Rates ◽  
Medium Voltage ◽  
Wide Range ◽  
Viscous Solution

Cellulose acetate (CA) nanofibers were electrospun in trifluoroacetic acid (TFA) under various conditions of concentration, voltage and dope flow rate while tip to collector distance (TCD) kept constant. Results showed that concentrations lower than 8 wt. % could only be electrospun at low flow rates. Bead free fibers were easily electrospun from higher CA concentrations 13 wt. % to 15 wt. %. Concentrations greater than 15 wt. % formed a viscous solution that could not be uniformly dispersed, thus impeding electrospinning. Medium voltage 20KV was found to produce good fibers while flow rates of 0.5ml/h and above, produced non-uniform fibers with a wide range. Average fiber diameters of 104nm and 129nm were formed at 13 wt. % and 15 wt. % (0.4ml/h, 20KV) respectively.

Image Analysis of Carry-Under by Falling Liquid Flow

2010 ◽  
Author(s):  
Tomohiko Ohtsuka ◽  
Naoki Haraguchi ◽  
Hiroyasu Ohtake ◽  
Yasuo Koizumi
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Flow Behavior ◽  
Wave Length ◽  
Video Camera ◽  
Water Jet ◽  
Water Pool ◽  
Nozzle Outlet ◽  
Pool Surface ◽  
High Speed Video Camera

Bubble carry-under into the water pool was examined. In experiments, a water jet from a nozzle of 5 mm in diameter plunged into the water pool. The distance between the nozzle outlet and the pool surface was 246 mm. Flow behavior in the water pool and also the state of the water jet surface were recorded with a high speed video camera. Following conclusions were obtained. When the flow rate of the water jet was small, the water jet disintegrated into small drops on the way from the nozzle outlet to the pool surface. The wave appearing position moved downward as the flow rate was increased. When the wave length reached the Kelvin-Helmholtz critical wave length, the water jet disintegrated into drops. When flow rate of the water jet was increased, the surface of the water jet became smooth and no perturbation was observed. The carry-under was not observed in this situation. When the flow rate of the water jet was further increased, large waves came to appear on the water jet surface. The wave appearing position moved upward as the flow rate was increased. Even if the wave length on the water jet reached the Kelvin-Helmholtz critical wave length, the water jet did not disintegrate into drops and the water jet plunges into the pool with large waves on the water jet. The penetration depth in this case was deep and the volume of the bubble carry-under was large compared with the case that the water jet disintegrated into drops.

Relationship between erythrocyte aggregate size and flow rate in skeletal muscle venules

2004 ◽  
Vol 286 (1) ◽  
pp. H113-H120 ◽  
Author(s):  
Jeffrey J. Bishop ◽  
Patricia R. Nance ◽  
Aleksander S. Popel ◽  
Marcos Intaglietta ◽  
Paul C. Johnson
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
High Speed ◽  
Aggregate Size ◽  
Video Camera ◽  
Low Flow ◽  
Shear Rates ◽  
Particle Length ◽  
Flow Stream ◽  
Low Shear

In previous studies we showed that intravenous infusion of Dextran 500 in the rat causes blunting of the velocity profile of red blood cells in venules at low shear rates. To determine whether this blunting is associated with the formation of red blood cell aggregates, we measured the length and width of particles in the venular flow stream at systemic hematocrits up to 20% with a high-speed video camera and a new image analysis technique. Data were obtained at various shear rates under normal (nonaggregating) conditions as well as after infusion of Dextran 500. Under normal conditions, particle length (parallel to the vessel axis) was 6.5 ± 2.7 μm and width (perpendicular to the axis) was 6.1 ± 1.7 μm, in agreement with published dimensions of individual red blood cells for this species. After Dextran 500 infusion, particle length and width increased significantly to 8.7 ± 5.1 and 10.4 ± 4.4 μm, respectively. Particle dimensions were greater in the central region of the flow stream for both normal and dextran-treated blood and increased at low flow rates with dextran-treated blood. This study provides direct confirmation of aggregate formation at low shear in venules with high-molecular-weight dextran as well as an estimate of aggregate size and range.

Modeling and Influence Study of Gas Bubbles on Characteristics of a Piezoelectric Valve-Less Micropump

2012 ◽  
Author(s):  
Songjing Li ◽  
Jixiao Liu ◽  
Dan Jiang
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Dynamic Pressure ◽  
Experimental Studies ◽  
Gas Bubbles ◽  
Video Camera ◽  
Pump Chamber ◽  
High Speed Video Camera ◽  
Outlet Flow ◽  
Trapped Gas

The aim of this paper is to develop a theoretical model of a piezoelectric valve-less micropump for liquid delivery with entrapped gas bubbles and evaluate the influence of gas bubbles on the dynamic characteristics of the micropump by using this model. In the model, we consider the vibration of piezoelectric diaphragm, the pressure loss through the nozzle/diffuser and the compressibility of working liquids with entrapped gas bubbles. In order to validate the developed model and make it useful as a design and prediction tool, experimental studies are carried out to investigate the flow rate and dynamic pressure inside the pump chamber when gas bubbles are absent or present in the micropump. The presence of gas bubbles inside the pump chamber is also observed with a high-speed video camera. The outlet flow rate of the micropump with different size of trapped gas bubbles are calculated and compared.

scholarly journals Pengaruh Diameter Piringan Katup Limbah Terhadap Tekanan Aliran Balik Dalam Pompa Hidram

Jurnal METTEK ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 98
Author(s):  
Kadek Bayu Laksana ◽  
Made Suarda ◽  
Ainul Ghurri
Keyword(s):  
Flow Pattern ◽  
Flow Rate ◽  
High Speed ◽  
Water Hammer ◽  
Back Pressure ◽  
High Speed Camera ◽  
Pressure Force ◽  
Drive Pipe ◽  
Disk Diameter ◽  
Movement Distance

Pompa hidram bekerja dengan memanfaatkan proses palu air. Terjadinya palu air akan mengakibatkan sebagian air menuju ke tabung udara dan sebagian lagi akan mengalami aliran balik pada pipa penggerak. Diameter piringan katup limbah mempengaruhi laju aliran dan gaya tekan di dalam badan pompa, sehingga akan mempengaruhi besarnya tekanan balik yang terjadi. Oleh sebab itu perlu dilakukan penelitian lebih lanjut mengenai pengaruh diameter piringan katup limbah terhadap tekanan aliran balik dalam pipa penggerak pompa hidram. Penelitian menggunakan variasi diameter piringan katup limbah 35 mm, 40 mm, 45 mm, 50 mm, dan 53 mm. Penelitian dilakukan dengan menggunakan kamera berkecepatan tinggi yaitu 960 fps, untuk merekam aliran balik yang sudah disemprotkan gliter sebelumnya. Sehingga didapatkan jarak pergerakan gliter untuk mendapat kecepatan dan pada akhirnya mendapat tekanan. Hasil dari penelitian menunjukkan diameter piringan katup limbah berpengaruh terhadap tekanan balik yang terjadi. Dimana head tekanan tertinggi terjadi pada diameter piringan katup limbah 40 mm sebesar 42.76 N/m2. Diikuti dengan debit pemompaan terbesar pada diameter piringan 42.88 mm sebesar 2.3 liter/menit. Selain tekanan, semakin besar diameter piringan katup limbah akan meningkatkan frekuensi dan efisiensi pompa hidram. Namun debit pembuangan menurun seiring bertambahnya diameter piringan. Hydram pump works by utilizing the water hammer process. Water hammer that take place some water flow into the air tube and some other will back into the drive pipe. The waste valve disk diameter affects the flow rate and the pressure force inside the pump body, so that it will affect the back pressure. Therefore it is necessary to conduct further research on the effect of the waste valve disk diameter to backflow pressure in the hydram pump drive pipe. The work used variations in diameter of 35 mm, 40 mm, 45 mm, 50 mm, and 53 mm. The flow pattern was recorded using a high-speed camera with 960 fps. The water was mixing with glitters. The glitter movement distance is obtained to get the speed and then its pressure. The results that show the diameter of the waste valve influences the back pressure. Finally the highest pressure is on the disk diameter 40 mm at 42.76 N/m2. Furthermore, the largest pumping debit was on a 42.88 mm disk diameter at 2.3 liters/minute. In addition, the larger valve disk diameter cause the higher frequency and efficiency. However, the waste debit decreases with increasing disk diameter.  

Motion Analysis of Striking Sports by Synchronizing High Speed Camera and Video Camera

2020 ◽  
Vol 2020 (0) ◽  
pp. 1P2-G05
Author(s):  
Kohei NISHIKAWA ◽  
Yosuke IKEGAMI ◽  
Kohei YAMAZAKI ◽  
Ko YAMAMOTO ◽  
Yoshihiko NAKAMURA
Keyword(s):  
Motion Analysis ◽  
High Speed ◽  
Video Camera ◽  
High Speed Camera

Effects of Alternate Leading Edge Cutback on Unsteady Cavitation in 4-Bladed Inducers

2001 ◽  
Vol 123 (4) ◽  
pp. 762-770 ◽  
Author(s):  
Yoshiki Yoshida ◽  
Yoshinobu Tsujimoto ◽  
Dai Kataoka ◽  
Hironori Horiguchi ◽  
Fabien Wahl
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Leading Edge ◽  
Cavitation Number ◽  
The Other ◽  
Low Flow ◽  
Pressure Measurements ◽  
High Speed Video ◽  
Cavitation Performance ◽  
Wide Range

A set of 4-bladed inducers with various amounts of cutback was tested with the aim of suppressing the rotating cavitation by applying alternate leading edge cutback. Unsteady cavitation patterns were observed by means of inlet pressure measurements and high-speed video pictures. It was found that the region with the alternate blade cavitation and asymmetric cavitation were enlarged with the increase of the amount of the cutback. As a result, the region with the rotating cavitation was diminished. At low flow rate, two types of alternate blade cavitation were found as predicted theoretically on 4-bladed inducer with smaller uneven blade length. One of them is with longer cavities on longer blades, and the other is with longer cavities on shorter blades. Switch was observed in these alternate blade cavitation patterns depending whether the cavitation number was increased or decreased. For an inducer with larger amount of cutback, the rotating cavitation and cavitation surge were almost suppressed as expected for a wide range of flow rate and cavitation number, although the cavitation performance was deteriorated. However, we should note that an asymmetric cavitation pattern occurs more easily in inducers with alternate leading edge cutback, and that the unevenness due to the cutback causes uneven blade stress.

Study on Shape Optimization of Calcium–Alginate Beads

2013 ◽  
Vol 648 ◽  
pp. 125-130 ◽  
Author(s):  
Zhao Qing Li ◽  
Li Da Hou ◽  
Zhen Li ◽  
Wei Zheng ◽  
Li Li
Keyword(s):  
Shape Optimization ◽  
Sodium Alginate ◽  
Flow Rate ◽  
Calcium Alginate ◽  
Calcium Salt ◽  
Solution Concentration ◽  
Alginate Beads ◽  
Cross Linking ◽  
Alginate Solution ◽  
Calcium Alginate Beads

In this paper, calcium–alginate beads have been manufactured by physically cross-linked technology, by dripping an aqueous alginate solution into a solution of calcium salt as a crosslinker. The effect of various elements controlling beads shape such as solution concentration, flow rate and the distance between the orifice tip and surface of the cross-linking solution were studied. The various elements affected the gelling rate and diameter and weight were studied. The findings indicated that shape of alginate beads in the hydrated state was strongly dependent on the flow rate and concentration of sodium alginate solutions.

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