Numerical simulation of droplet ejection of thermal inkjet printheads

Tan, Hua; Torniainen, Erik D.; Markel, David P.; Browning, Robert N K

doi:10.1002/fld.3997

Cited by 26 publications

(21 citation statements)

References 62 publications

(85 reference statements)

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“…The final speed of projectile is approximately ~12m/ s which agrees with previous numerical and experimental studies [11, 15, 43, 44]. The drop head velocity at any instance of time is depicted in Fig.…”

Section: Thermal Inkjet Printersupporting

confidence: 88%

“…Moreover, the geometry of their printhead is significantly more complicated compared to HP60. Although different print head geometry is used in our simulation, it is observed that our numerical results roughly matches the experimental result and CFD simulation of Tan et al [43]. The main reason for lower printhead velocity is using nozzle with bigger diameter, 48μm, compared to Tan et al work [3] where it was 20 μm .…”

Section: Thermal Inkjet Printersupporting

confidence: 78%

“…Thus, only the pressure information, force on the liquid surface, is passed onto fluid solver. However, due to high temperature and density gradient in the bubble region, bubble dynamic might be different from what has been previously realized [11, 14, 43–45]. Due to high dependency of local pressure, density and temperature on each other, EOS is needed to be directly implemented.…”

Section: Thermal Inkjet Printermentioning

confidence: 96%

“…To overcome this issue, the flow in the vapor domain is ignored in literature and vapor bubble is treated as a cavity so that the bubble can freely expand and shrink [43]. Thus, only the pressure information, force on the liquid surface, is passed onto fluid solver.…”

Section: Thermal Inkjet Printermentioning

confidence: 99%

“…The drop head velocity at any instance of time is depicted in Fig. 15 where it is compared with experimental measurement and CFD modeling of Tan et al [43]. Drophead velocity is directly linked to Bubble expansion rate.…”

Section: Thermal Inkjet Printermentioning

confidence: 99%

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Modeling thermal inkjet and cell printing process using modified pseudopotential and thermal lattice Boltzmann methods

Sohrabi

Liu

2018

Phys. Rev. E

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Pseudopotential Lattice Boltzmann methods (LBM) can simulate phase transition in high-density ratio multiphase flow systems. If coupled with thermal LBM through equation of state, it can be used to study instantaneous phase transition phenomena with high temperature gradient where only one set of formulations in LBM system can handle liquid, vapor, phase transition, and heat transport. However, at lower temperatures unrealistic spurious current at interface introduce instability and limit its application in real flow system. In this study, we proposed new modifications to LBM system to minimize spurious current which enables us to study nucleation dynamic at room temperature. To demonstrate the capabilities of this approach, thermal ejection process is modeled as one example of a complex flow system. In inkjet printer, a thermal pulse instantly heats up the liquid in microfluidic chamber and nucleate bubble vapor providing pressure pulse necessary to eject droplets at high speed. Our modified method can present a more realistic model of explosive vaporization process since it can also capture high temperature/density gradient at nucleation region. Thermal inkjet technology has been successfully applied for printing cells, but cells are susceptible to mechanical damage or death as they squeeze out of nozzle head. To study cell deformation, spring network model, representing cells, is connected to LBM through immersed boundary method. Looking into strain/stress distribution of cell membrane at its most deformed state, it is found that high stretching rate effectively increase rupture tension. In other word, membrane deformation energy is released thorough creation of multiple smaller nanopores rather than big pores. Overall, concurrently simulating multiphase flow, phase transition, heat transfer, and cell deformation in one unified LB platform, we were able to provide a better insight into bubble dynamic and cell mechanical damage during printing process.

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Section: Thermal Inkjet Printersupporting

confidence: 88%

Section: Thermal Inkjet Printersupporting

confidence: 78%

Section: Thermal Inkjet Printermentioning

confidence: 96%

Section: Thermal Inkjet Printermentioning

confidence: 99%

Section: Thermal Inkjet Printermentioning

confidence: 99%

See 3 more Smart Citations

Modeling thermal inkjet and cell printing process using modified pseudopotential and thermal lattice Boltzmann methods

Sohrabi

Liu

2018

Phys. Rev. E

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Absorption of picoliter droplets by thin porous substrates

Tan

2016

AIChE Journal

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Absorption of picoliter (pL) droplets into porous substrates is studied experimentally and numerically. In the case of pL droplets, major phenomena involved in the interaction between droplet and porous media develop at different time scales: spreading and wetting at microseconds, absorption and wicking at milliseconds, and evaporation at seconds. Therefore, one can decouple these processes to minimize the complexity of the study. A high-speed imaging system capable of 1 million frames per second is used to visualize individual droplets impacting, spreading, and imbibing on substrates. To simulate droplet dynamics, the governing equations for flow outside and inside porous media are proposed and solved using an in-house developed computational fluid dynamics solver. The simulation results are in good agreement with the experimental data. The effect of drop impact velocity and fluid properties on final dot shape in the porous substrates is investigated through a series of parametric numerical studies.

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