Acoustics of a piezo inkjet channel with an entrained air bubble

2019 ◽  
Vol 146 (4) ◽  
pp. 2755-2756
Author(s):  
Tim Segers ◽  
Arjan Fraters ◽  
Hans Reinten ◽  
Youri de Loore ◽  
Detlef Lohse ◽  
...  
Keyword(s):  
Air Bubble ◽  
Entrained Air

scholarly journals A Study of Bubble Entrainment as Related to Runner Velocity in Aluminum Sand Castings Using the Cosworth Process

2007 ◽  
Vol 539-543 ◽  
pp. 398-403 ◽  
Author(s):  
John C. Burford ◽  
Jerry Sokolowski
Keyword(s):  
Transient Flow ◽  
Metal Flow ◽  
Critical Value ◽  
Low Velocity ◽  
Air Bubble ◽  
Aluminum Castings ◽  
Bubble Entrainment ◽  
Open Production ◽  
Entrained Air ◽  
Flow Experiences

Traditional gravity pour down-sprue methods of filling moulds in the making of aluminum castings inherently lead to oxide and air bubble entrainment. The reason for this is found in the high velocities the metal flow experiences during the filling of a mould. The Nemak Windsor Aluminum Plant (WAP) produces cylinder blocks using the low-pressure Cosworth process, which includes low velocity up-hill filling of the sand mould package. This doctrine is followed in all except one part of the process: the runner system. The nature of the resulting defect is generally known as Head Deck Porosity. Runners were cast full in open production runners at three different velocities with the resulting quickly chilled castings analyzed using X-ray radioscopy, and Scanning Electron Microscopy. Results reveal that the subject bubble porosity is indeed the result of air entrained during initial transient flow within the production runner system whose velocity is higher than the critical value of 0.5ms-1. This theoretical value is corroborated by experimental results. In addition, a new "sessile" runner of optimized shape, filled at a velocity slower than the critical value, is proposed and analyzed using Magmasoft mould fill modelling software. The design can potentially replace the existing runner providing a casting free of entrained air.

Effects of Entrained Air on the Performance of a Horizontal Axial-Flow Pump

1983 ◽  
Vol 105 (4) ◽  
pp. 382-388 ◽  
Author(s):  
Mitsukiyo Murakami ◽  
Kiyoshi Minemura
Keyword(s):  
Weber Number ◽  
Radial Flow ◽  
Liquid Flow Rate ◽  
Axial Flow ◽  
Analytical Models ◽  
Air Bubble ◽  
Axial Flow Pump ◽  
Entrained Air ◽  
Air Void ◽  
Flow Pump

The performance of an axial-flow pump was investigated under air-admitting conditions and the results were compared with those obtained for radial-flow pumps investigated in our previous studies. For the axial-flow pump we measured head as a function of impeller speed, liquid flow rate, and air void fraction. Flow visualization was performed and we correlated air bubble size as a function of Weber number based on mean impeller velocity. Overall flow patterns and the locations of air coalesence within the impeller were observed and diagrammed. These data contribute to earlier data obtained by ourselves and others to develop analytical models to predict pump performance degradation due to air admittance.

scholarly journals Shortwave infrared imaging setup to study entrained air bubble dynamics in a MEMS-based piezo-acoustic inkjet printhead

2019 ◽  
Vol 60 (8) ◽  
Author(s):  
Arjan Fraters ◽  
Tim Segers ◽  
Marc van den Berg ◽  
Hans Reinten ◽  
Herman Wijshoff ◽  
...  
Keyword(s):  
Bubble Dynamics ◽  
Infrared Imaging ◽  
Air Bubble ◽  
Entrained Air ◽  
Shortwave Infrared ◽  
Inkjet Printhead ◽  
Imaging Setup

scholarly journals Unconfined Dense Plunging Jets Used for Brine Disposal from Desalination Plants

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 696
Author(s):  
Aaron C. Chow ◽  
Ishita Shrivastava ◽  
E. Eric Adams ◽  
Fahed Al-Rabaie ◽  
Bader Al-Anzi
Keyword(s):  
Water Column ◽  
Penetration Depth ◽  
Laboratory Experiments ◽  
Buoyant Jets ◽  
Air Bubble ◽  
Plunging Jets ◽  
Desalination Plants ◽  
Entrained Air ◽  
Neutrally Buoyant ◽  
Receiving Water

Laboratory experiments were conducted to measure entrained air bubble penetration depth and dilution of a dense vertical unconfined plunging jet to evaluate its performance as an outfall to dilute brine from desalination plants as well as a means to aerate water column. Experiments involved neutrally buoyant or dense plunging jets discharging in quiescent receiving water. The density difference between effluent and receiving water, the plunging jet length (height above water surface), and the receiving water salinity were varied in the experiments. Observed penetration depth for neutrally buoyant jets was somewhat greater than previously reported, and increased modestly with jet density. Increasing density also resulted in an increasing number of fine bubbles descending together with the dense plume. These observations can help guide the design of plunging jets to mitigate anoxic conditions in the water column when brine is introduced to a receiving water body, as with seawater desalination.

scholarly journals Experimental Development of a Novel Mine Backfill Material: Foam Mine Fill

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 564
Author(s):  
Mohammed Hefni ◽  
Ferri Hassani
Keyword(s):  
Mixing Time ◽  
Working Environment ◽  
Dry Density ◽  
Experimental Development ◽  
Hydraulic Fill ◽  
Mine Backfill ◽  
Air Bubble ◽  
Backfill Material ◽  
Bubble Structure ◽  
Entrained Air

This study aims to develop a novel mine backfill material called foam mine fill (FMF). A cellular structure is achieved by incorporating a premade foam into the backfill mixture using an air-entraining agent. FMF samples were prepared with copper-nickel mine tailings and normal Portland cement. Experiments were designed to investigate the effect of binder dosage, volume of entrained air, and foam mixing time on FMF unconfined compressive strength (UCS) and dry density. Moreover, a qualitative microscopic assessment investigated the effect of foam mixing time on air bubble structure. The pore size distribution and porosity of selected samples were investigated through mercury intrusion porosimetry. Relative to reference samples without entrained air, the UCS of FMF samples was 20–50% lower. However, the concomitant lower dry density (by up to 360 kg/m3) could enhance the safety of the underground working environment, especially in underhand cut-and-fill mining where miners and machinery work beneath the backfilled stope, and lower-density fill material would minimize the adverse effects of potential backfill failure. Prolonged foam mixing time led to a significant loss in UCS and total collapse of the air bubble structure. Other potential applications for FMF are areas where there are tailings shortages and as an alternative to hydraulic fill.

A Condition for an Air Entrainment by Breaking the Surface Waves at the Free Surface

2005 ◽  
Author(s):  
Ho-Yun Nam ◽  
Jong-Man Kim ◽  
Byoung-Hae Choi ◽  
Jong-Hyeun Choi
Keyword(s):  
Free Surface ◽  
Surface Wave ◽  
Water Flow Rate ◽  
Air Entrainment ◽  
Vessel Diameter ◽  
Test Facility ◽  
Critical Conditions ◽  
Air Bubble ◽  
Water Test ◽  
Entrained Air

An experimental study has been carried out to measure the critical conditions for the inception of an air entrainment by breaking the surface wave at the free surface in the water test facility. The experimental parameters are the vessel diameter, the nozzle diameter, the mean water-level and the water flow rate. More than 400 experimental data which show whether the air is entrained or not at a given experimental condition are obtained, and an experimental correlation that describes the air entrainment condition is developed. The correlation is described by the ratio between the diameter and height of the vessel, the ratio between the diameter of the nozzle and the height of the vessel, the modified Froude number and a modified Weber number. In this experiment two cases of air entrainment are observed. One case is that the air entrainment occurred due to the destruction of the surface wave from the center, and the other case is due to the crash of the water wave to the vessel wall. Theses two cases occur irregularly and the entrained air bubble distributes uniformly in the water.

A RELAP5/MOD3 Model for the Estimation of Air Pull-Through for a Draining Tank

2004 ◽  
Author(s):  
D. S. Lucas ◽  
R. Riemke
Keyword(s):  
Air Entrainment ◽  
Air Bubble ◽  
Vortex Model ◽  
Pull Through ◽  
Entrained Air

An air pull-through vortex model was implemented in RELAP5/MOD3 to investigate air-entrainment from a draining tank. Surge tanks covered by an air bubble are vulnerable to the entrainment of air into the liquid. If such a system is connected to a pump the possibility of entrained air from draining resulting in cavitation and pump degradation is possible.

Effect of an entrained air bubble on the acoustics of an ink channel

2008 ◽  
Vol 123 (5) ◽  
pp. 2496-2505 ◽  
Author(s):  
Roger Jeurissen ◽  
Jos de Jong ◽  
Hans Reinten ◽  
Marc van den Berg ◽  
Herman Wijshoff ◽  
...  
Keyword(s):  
Air Bubble ◽  
Entrained Air
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