Characterization of droplet ejection process for a full-size piezoelectric inkjet printhead

2005 ◽  
Author(s):  
An-Shik Yang ◽  
Chiang-Ho Cheng
Keyword(s):  
Full Size ◽  
Droplet Ejection ◽  
Ejection Process ◽  
Inkjet Printhead

Investigation of Droplet-Ejection Characteristics for a Piezoelectric Inkjet Printhead

2006 ◽  
Vol 220 (4) ◽  
pp. 435-445 ◽  
Author(s):  
A-S Yang ◽  
C-H Cheng ◽  
C-T Lin
Keyword(s):  
Surface Tension ◽  
Piecewise Linear ◽  
Time Interval ◽  
Force Model ◽  
Ejection Time ◽  
Theoretical Formulation ◽  
Construction Technique ◽  
Droplet Ejection ◽  
Ejection Process ◽  
Inkjet Printhead

Numerical simulations are performed to explore the droplet-ejection process for a piezoelectric inkjet printhead. In the analysis, the theoretical model takes account of a set of three-dimensional, time-dependent conservation equations of mass and momentum, with the incorporation of the continuous surface force model for treating the interfacial surface tension effect. The resultant governing equations are solved using an iterative semi-implicit method for pressure-linked equations consistent algorithm for resolving flow properties. The volume-of-fluid method along with the piecewise linear-interface construction technique is implemented to characterize the behaviour of liquid surface movement. With a typical piezodiaphragm printhead as an illustration case, the time evolution of the gas-liquid interface is calculated for an entire ejection cycle of 164 μs. The predicted droplet shapes throughout the ejection process are compared with microphotographed images for the verification of the present theoretical formulation. The flow and transport phenomena in the stages of the ink ejection and the droplet formation are further examined in detail. In response to design needs, the study is extended to determine the variations of ejection characteristics at different settings of nozzle exit diameter, ejection time interval, surface tension, and viscosity of fluid.

Numerical Simulation of Droplet Ejection Based on VOF Method

2014 ◽  
Vol 548-549 ◽  
pp. 1257-1264 ◽  
Author(s):  
Xiao Yong Suo
Keyword(s):  
Numerical Simulation ◽  
Surface Tension ◽  
Numerical Model ◽  
Physical Properties ◽  
Vof Method ◽  
Numerical Results ◽  
Droplet Ejection ◽  
Ejection Process ◽  
Ink Jet ◽  
Jet Nozzle

Taking ejection process of the ink droplets from ink-jet nozzle as the prototype, a similar numerical model of droplet ejection was established. The VOF method was applied to track the interface of droplet ejection process and it is shown that the numerical results simulated by the VOF method were accurate and reliable. Six kinds of liquid with different physical properties were chosen as the research object. The numerical results were analyzed and compared. Finally, the effect of the surface tension, viscosity and density on the droplet ejection process was discussed.

scholarly journals Pressure response and droplet ejection of a piezoelectric inkjet printhead

1999 ◽  
Vol 41 (2) ◽  
pp. 235-248 ◽  
Author(s):  
Ping-Hei Chen ◽  
Hsin-Yah Peng ◽  
Hsin-Yi Liu ◽  
S.-L. Chang ◽  
T.-I. Wu ◽  
...  
Keyword(s):  
Pressure Response ◽  
Droplet Ejection ◽  
Inkjet Printhead

CFD Model of the Thermal Inkjet Droplet Ejection Process

2007 ◽  
Author(s):  
O. E. Ruiz
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Computational Model ◽  
Bubble Formation ◽  
Firing Cycle ◽  
Coupled Flow ◽  
Droplet Ejection ◽  
Ejection Process ◽  
Model Predictions ◽  
Phase Change Heat Transfer

Numerical simulations of the thermal inkjet (TIJ) droplet ejection process are performed. The computational approach is based on a volume of fluid (VOF) formulation. This method allows determining the coupled flow and thermal fields in the firing chamber in addition to the phase change processes that take place during the drive bubble formation, expansion, and collapse. The drive bubble pressure is a result of the phase change heat transfer during the heating pulse and is not imposed by a pressure heuristic approach. A commercially available TIJ architecture was chosen as a baseline to assess the computational model predictions of ejected droplet volume and droplet velocity during a firing cycle. These computational model predictions were compared to experimental results demonstrating an excellent agreement. The transient histories of pressure in the vapor bubble, temperature, and heat transfer rate to the fluid are analyzed to explain some of the relevant physical processes observed.

Optical Diagnostics for Characterization of a Full-Size Fighter-Jet Afterburner

2005 ◽  
Author(s):  
H. Seyfried ◽  
G. Sa¨rner ◽  
A. Omrane ◽  
M. Richter ◽  
H. Schmidt ◽  
...  
Keyword(s):  
Spectral Characteristics ◽  
Aircraft Engine ◽  
Jet Stream ◽  
Outlet Nozzle ◽  
Full Size ◽  
Thermographic Phosphors ◽  
Unburned Fuel ◽  
Optical Laser ◽  
Dimensional Surface

In the present work the feasibility of using various optical/laser based techniques for characterization of the afterburner of a full-size aircraft engine have been investigated. The tests have been performed on-site at Volvo Aero Corporation and were mainly directed towards surface thermometry using thermographic phosphors and fuel visualization. All applications were studied for different engine running conditions, including various use of the afterburner (A/B). Laser-Induced Fluorescence (LIF) was employed for fuel visualization to investigate to what extent unburned fuel exits the afterburner. Laser-Induced Phosphorescence (LIP) from thermographic phosphors was used to measure two-dimensional surface temperatures on the outlet nozzle of the afterburner. In addition, the spectral characteristics of the burning jet stream were investigated.

Construction and characterization of a plasmid containing a nearly full-size DNA copy of bacteriophage MS2 RNA

1979 ◽  
Vol 128 (4) ◽  
pp. 595-619 ◽  
Author(s):  
René Devos ◽  
John van Emmelo ◽  
Roland Contreras ◽  
Walter Fiers
Keyword(s):  
Full Size ◽  
Bacteriophage Ms2
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