Numerical Simulation on the Formation Process of Metal Droplets by Pneumatic Diaphragm Drop-on Demand Technology

2019 ◽  
Author(s):  
Kun Ma ◽  
Sheng Liu ◽  
Zhiwen Chen ◽  
Li Liu ◽  
Hao Zheng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Formation Process ◽  
On Demand ◽  
Drop On Demand ◽  
Metal Droplets

Modeling and characterization of metal droplets generation by using a pneumatic drop-on-demand generator

2012 ◽  
Vol 212 (3) ◽  
pp. 718-726 ◽  
Author(s):  
Jun Luo ◽  
Le-hua Qi ◽  
Ji-ming Zhou ◽  
Xiang-hui Hou ◽  
He-jun Li
Keyword(s):  
On Demand ◽  
Drop On Demand ◽  
Metal Droplets

Numerical Simulation on Deposition and Solidification Processes of a Molten Metal Droplet Generated by Drop-on-Demand Jetting

2012 ◽  
Vol 538-541 ◽  
pp. 890-894 ◽  
Author(s):  
Peng Yun Wang ◽  
He Jun Li ◽  
Le Hua Qi ◽  
Hai Liang Deng ◽  
Han Song Zuo
Keyword(s):  
Numerical Simulation ◽  
Substrate Temperature ◽  
Metal Droplet ◽  
Dimensional Accuracy ◽  
Droplet Deposition ◽  
On Demand ◽  
Drop On Demand ◽  
Solidification Processes ◽  
Droplet Spray ◽  
Uniform Droplet

Droplet deposition and solidification is vital to dimensional accuracy and mechanical properties of components prepared by uniform droplet spray (UDS) forming. In this paper, a volume-of-fluid (VOF) based model was developed to study the deposition and solidification processes of a 1 mm Al-4.5%Cu droplet generated by drop-on-demand jetting. The effects of droplet falling velocity (0.6-0.8 m/s), initial temperature (933-973 K), and substrate temperature (300-473 K) were investigated. The results show that the final morphology of the deposited droplet is largely dependent on falling velocity and substrate temperature. The solidified droplet obtained from an UDS experiment validates the numerical simulation.

Study of Droplet Formation Process during Drop-on-Demand Inkjetting of Living Cell-Laden Bioink

Langmuir ◽  
2014 ◽  
Vol 30 (30) ◽  
pp. 9130-9138 ◽  
Author(s):  
Changxue Xu ◽  
Meng Zhang ◽  
Yong Huang ◽  
Amod Ogale ◽  
Jianzhong Fu ◽  
...  
Keyword(s):  
Formation Process ◽  
Living Cell ◽  
Droplet Formation ◽  
On Demand ◽  
Drop On Demand

Relevant Influencing Factors on Droplet Characteristics for a Piezoelectrically Driven Drop-on-Demand Printhead

2014 ◽  
Author(s):  
Markus Kagerer ◽  
Arne Meeuw ◽  
Jan Berger ◽  
Dominik Rumschoettel ◽  
Tim C. Lueth ◽  
...  
Keyword(s):  
Surface Tension ◽  
Formation Process ◽  
Droplet Formation ◽  
Electrical Excitation ◽  
Fluid Mixture ◽  
Nozzle Length ◽  
On Demand ◽  
Drop On Demand ◽  
Fluid Properties

Dispensing minute amounts of fluid is used in many industries, such as in life science, bioengineering, 3D printing, or in electronics manufacturing. Each application for drop-on-demand (DoD) printheads requires different drop volumes and drop velocities. Furthermore, it is necessary to eject droplets made of fluids with different fluid properties, like viscosity, surface tension, or density. Due to this wide range of different applications and demands on printheads it is important to investigate the influence of relevant factors on the droplet formation process. Therefore, the influence of the fluid properties, the printhead geometry, and the electrical excitation form on the droplet formation process are described in this project. In detail, the influence of the surface tension as well as the viscosity of the fluid, the nozzle length and its width, and the amplitude of the applied voltage at different pulse widths on the droplet characteristics are investigated. The used printhead consists of a silicon chip, which includes the fluidic components, and of a bimorph piezoelectric actuator. The printhead is manufactured with rapid manufacturing techniques, such as laser micromachining. The advantage of this method is that the printhead is adaptable to new boundary conditions in a time- and cost-saving manner. In this project, the nozzles have a square shape with a sidelength between 50 and 100 μm and the nozzle length varies between 50 and 200 μm. A fluid mixture is provided which can be varied in its fluid properties. Therefore, the possibility for the independent adjustment of its viscosity and its surface tension is given. The mixture consists of glycerin, distilled water, and isopropanol. An analytical description for each amount of its substances enables to provide a fluid with defined properties. Three kinds of experiments are carried out in order to determine the influence of the fluid properties, the printhead geometry, and the electrical excitation on the droplet formation process. The determination of the minimum excitation voltage needed for droplet ejection and the determination of the droplet volume and its velocity. The main results are: The higher the surface tension, viscosity, and nozzle length, the higher is the minimum excitation voltage. Furthermore, the droplet velocity decreases for an increased surface tension, viscosity, and nozzle length. On the other hand, the droplet velocity increases with an enlarged amplitude of the voltage and pulse width. The droplet volume increases for an increased surface tension, nozzle width, pulse width, and amplitude of the voltage. In general, the reasons for these correlations are the interaction between the strength of the pressure pulse, friction forces, fluidic resistances, and fluid properties. Overall, the possibility to achieve microdroplets made of different fluids and with a specific velocity and volume is described. Furthermore, a fluid mixture, which can be varied in its fluid properties, is presented.

Effect of Substrate Temperature on Splashing of Molten Metal Droplets

Volume 1 ◽  
2004 ◽  
Author(s):  
Rajeev Dhiman ◽  
Sanjeev Chandra
Keyword(s):  
Substrate Temperature ◽  
Molten Metal ◽  
High Impact ◽  
Small Satellite ◽  
Solid Layer ◽  
Uniform Size ◽  
On Demand ◽  
Drop On Demand ◽  
Splat Thickness ◽  
Metal Droplets

The effect of substrate temperature on the splashing of molten metal droplets was studied experimentally. Uniform-size molten tin droplets (550 μm diameter) were produced using a drop-on-demand generator. To achieve high impact velocities substrates were mounted on the rim of a rotating flywheel and heated using cartridge heaters to vary substrate temperature. Droplets hitting a smooth cold substrate splashed extensively producing many small satellite droplets and leaving on the surface a small, irregular splat with many fingers projecting from its periphery. Droplets hitting a hot substrate did not splash but spread out to form a smooth disc. A new splashing criterion was developed to calculate the substrate temperature at which this transition occurred. It assumes splashing to occur when the solid layer produced as a result of droplet solidification grows equal to the splat thickness and obstructs the spreading liquid.

NUMERICAL SIMULATION OF FORMATION PROCESS OF 3D ANTIDUNES

2019 ◽  
Vol 75 (2) ◽  
pp. I_1003-I_1008
Author(s):  
Shinichiro ONDA ◽  
Ryoya INABA ◽  
Takashi HOSODA
Keyword(s):  
Numerical Simulation ◽  
Formation Process
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