A Theoretical Model for Steam Laser Cleaning

1998 ◽  
Vol 526 ◽  
Author(s):  
Y. F. Lu ◽  
Y. Zhang ◽  
W. D. Song ◽  
T. S. Low
Keyword(s):  
Theoretical Model ◽  
Liquid Film ◽  
Solid Surface ◽  
Laser Fluence ◽  
Adhesion Force ◽  
Thin Liquid Film ◽  
Laser Cleaning ◽  
Superheated Liquid ◽  
Cleaning Efficiency ◽  
The Difference

AbstractA theoretical model for removal of tiny particles from solid surface covered with a thin liquid film by laser cleaning is established by taking adhesion force and cleaning force into account. When pulsed laser irradiates on the solid surface coated with a thin liquid film, a sheet of liquid near the liquid/substrate interface can be superheated through thermal diffusion. The rapid growth of vapor bubbles inside the superheated liquid can generate transient stress wave with high pressure, large enough to expel micron and sub-micron particles from the contaminated surface. By calculating the adhesion force and cleaning force, the cleaning threshold of laser fluence can be predicted from this theoretical model. The difference between cleaning force and adhesion force increases quickly along with the laser fluence and leads to higher cleaning efficiency.

Molecular Dynamics Study on Explosive Boiling of Thin Liquid Argon Film on Nanostructured Surface Under Different Wetting Conditions

2015 ◽  
Author(s):  
Sheikh Mohammad Shavik ◽  
Mohammad Nasim Hasan ◽  
A. K. M. Monjur Morshed
Keyword(s):  
Molecular Dynamics ◽  
Liquid Film ◽  
Solid Surface ◽  
Solid Wall ◽  
Thin Liquid Film ◽  
Liquid Argon ◽  
Spatial And Temporal Variation ◽  
Phase System ◽  
Explosive Boiling ◽  
System Pressure

Molecular dynamics (MD) simulations have been performed to investigate the boiling phenomena of thin liquid film adsorbed on a nanostructured solid surface with particular emphasis on the effect of wetting condition of the solid surface. The molecular system consists of liquid and vapor argon, and solid platinum wall. The nanostructures which reside on top of the solid wall have shape of rectangular block. The solid-liquid interfacial wettability, in other words whether the solid surface is hydrophilic or hydrophobic has been altered for different cases to examine its effect on boiling phenomena. The initial configuration of the simulation domain comprised a three phase system (solid platinum, liquid argon and vapor argon) which was equilibrated at 90 K. After equilibrium period, the wall temperature was suddenly increased from 90 K to 250 K which is far above the critical point of argon and this initiates rapid or explosive boiling. The spatial and temporal variation of temperature and density as well as the variation of system pressure with respect to time were closely monitored for each case. The heat flux normal to the solid surface was also calculated to illustrate the effectiveness of heat transfer for different cases of wetting conditions of solid surface. The results show that the wetting condition of surface has significant effect on explosive boiling of the thin liquid film. The surface with higher wettability (hydrophilic) provides more favorable conditions for boiling than the low-wetting surface (hydrophobic) and therefore, liquid argon responds quickly and shifts from liquid to vapor phase faster in case of hydrophilic surface.

Linear Stability of Thin Liquid Film On Solid Surface Under Effect of Apolar and Electrostatic Forces

2012 ◽  
Author(s):  
Mohanad El–Harbawi ◽  
Luqman Chuah Abdullah ◽  
Shean Yaw Thomas Choong ◽  
Siti Aslina Hussain ◽  
Azni Idris
Keyword(s):  
Liquid Film ◽  
Linear Stability ◽  
Solid Surface ◽  
Thin Liquid Film ◽  
Navier Stokes ◽  
Electrostatic Forces

Kestabilan lapisan tipis cecair pada permukaan pepejal di bawah kuasa kutub dan elektrostatik dikaji. Aliran ditunjukkan oleh persamaan Navier–Stokes dua dimensi dipasangkan dengan persamaan penerusan serta digabungkan dengan garisan sempadan. Lapisan tipis adalah dimodelkan sebagai cecair Newtonian dua dimensi ketumpatan, ρ dan kelikatan, μ mengalir pada permukaan mendatar. Lapisan tebal purata, h0 adalah dianggap cukup tebal untuk mengabaikan kesan graviti dan dihadkan oleh gas pasif serta ditambah pada sisinya kepada infiniti (model dua dimensi). Kuasa jasad pada persamaan Navier–Stokes telah diubahsuai dengan mengambil kira interaksi di antara (kuasa kutub dan elektrostatik) lapisan cecair dengan permukaan pepejal disebabkan oleh kuasa kutub dan elektrostatik. Pengubahsuaian persamaan Navier–Stokes dengan gabungan garisan sempadan diselesaikan dengan menggunakan persamaan panjang gelombang untuk mendapatkan persamaan tidak lurus evolusi permukaan–permukaan lapisan. Bahagian kuasa elektrostatik adalah lebih besar dalam nilai kuasa kutub dan berpengaruh terhadap sifat lapisan tipis serta kesan utama pada sifat–sifat tenaga bebas berlebihan, kadar penambahan, kadar penambahan maksimum, nombor gelombang natural, nombor gelombang berpengaruh dan masa pecahan. Maka, teori linear adalah kurang menunjukkan sifat-sifat kestabilan lapisan. Pengiraan menunjukkan bahawa kuasa kutub dan elektrostatik hanya boleh digunakan untuk penghasilan lapisan mendatar dengan ketebalan h0

Generating one-dimensional micro- or nano-structures with in-plane alignment by vapor-driven wetting kinetics

2017 ◽  
Vol 4 (2) ◽  
pp. 259-267 ◽  
Author(s):  
Chuan Liu ◽  
Xuying Liu ◽  
Yong Xu ◽  
Huabin Sun ◽  
Yun Li ◽  
...  
Keyword(s):  
Liquid Film ◽  
Solid Surface ◽  
Thin Liquid Film ◽  
One Dimensional ◽  
Nanostructure Formation ◽  
Nano Structures ◽  
Wetting Kinetics

The wetting of a droplet on a particular solid surface of a thin liquid film followed by solvent drying is a crucial process for nanostructure formation.

Nanostructures Length Effect on Phase Transition Phenomena of Ultra-Thin Liquid Film From a Nanostructured Surface: A Molecular Dynamics Study

2011 ◽  
Author(s):  
A. K. M. M. Morshed ◽  
T. C. Paul ◽  
Jamil A. Khan
Keyword(s):  
Molecular Dynamics ◽  
Film Thickness ◽  
Liquid Film ◽  
Solid Surface ◽  
Thin Liquid Film ◽  
Liquid Argon ◽  
Liquid Film Thickness ◽  
Dynamics Simulation ◽  
Phase System ◽  
Three Phase

A molecular dynamics simulation has been employed to investigate the boiling phenomena of few molecular-layer thin liquid-film adsorbed on a nanoscale roughened solid surface. The molecular system comprises of three phase system: solid platinum wall, liquid argon and argon vapor. A few layer of liquid argon has been placed on the nanoposts decorated solid surface where nanoposts ensemble surface roughness. Nanoposts height has been varied keeping liquid film thickness constant to capture three scenario: (i) Liquid-film thickness is higher than the height of the nanoposts (ii) Liquid-film and nanoposts are of same height (iii) Liquid-film thickness is less than the height of the nanoposts. Rest of the simulation box space has been filled with argon vapor. The simulation starts from the equilibrium three phase system and then suddenly the wall is heated to a higher temperature which resembles an ultra fast laser heating. Two different jump temperatures has been selected: one is a few degrees above the boiling point to initiate normal evaporation and the other one is far above the critical point temperature to initiate explosive boiling. Simulation results indicate nanostructures play significant role in both the cases. Argon responds very quickly in the nanoposts decorated surface and evaporation rate increases with the nanoposts height. Different boiling behavior has been observed for the nanoposts decorated surface.

Molecular Dynamics Study on Explosive Boiling of Thin Liquid Argon Film on Nanostructured Surface Under Different Wetting Conditions

2016 ◽  
Vol 138 (1) ◽  
Author(s):  
Sheikh Mohammad Shavik ◽  
Mohammad Nasim Hasan ◽  
A. K. M. Monjur Morshed
Keyword(s):  
Heat Transfer ◽  
Molecular Dynamics ◽  
Liquid Film ◽  
Solid Surface ◽  
Thin Liquid Film ◽  
Liquid Argon ◽  
Spatial And Temporal Variation ◽  
Phase System ◽  
Hydrophilic Surface ◽  
Explosive Boiling

Molecular dynamics (MDs) simulations have been performed to investigate the boiling phenomena of thin liquid film adsorbed on a nanostructured solid surface with particular emphasis on the effect of wetting condition of the solid surface. The molecular system consists of liquid and vapor argon and solid platinum wall. The nanostructures which reside on top of the solid wall have shape of rectangular block. The solid–liquid interfacial wettability, in other words whether the solid surface is hydrophilic or hydrophobic, has been altered for different cases to examine its effect on boiling phenomena. The initial configuration of the simulation domain comprises a three-phase system (solid platinum, liquid argon, and vapor argon), which was equilibrated at 90 K. After equilibrium period, the wall temperature was suddenly increased from 90 K to 250 K which is far above the critical point of argon and this initiates rapid or explosive boiling. The spatial and temporal variation of temperature and density as well as the variation of system pressure with respect to time were closely monitored for each case. The heat flux normal to the solid surface was also calculated to illustrate the effectiveness of heat transfer for different cases of wetting conditions of solid surface. The results show that the wetting condition of surface has significant effect on explosive boiling of the thin liquid film. The surface with higher wettability (hydrophilic) provides more favorable conditions for boiling than the low-wetting surface (hydrophobic), and therefore, the liquid argon responds quickly and shifts from liquid to vapor phase faster in the case of hydrophilic surface. The heat transfer rate is also much higher in the case of hydrophilic surface.

Effect of Approach Velocity on Thin Liquid Film Drainage between an Air Bubble and a Flat Solid Surface

2017 ◽  
Vol 121 (10) ◽  
pp. 5573-5584 ◽  
Author(s):  
Xurui Zhang ◽  
Rogerio Manica ◽  
Plamen Tchoukov ◽  
Qingxia Liu ◽  
Zhenghe Xu
Keyword(s):  
Liquid Film ◽  
Solid Surface ◽  
Thin Liquid Film ◽  
Air Bubble ◽  
Film Drainage ◽  
Approach Velocity

C133 Evaporation Characteristics of an Ultra Thin Liquid Film on a Solid Surface

2005 ◽  
Vol 2005 (0) ◽  
pp. 113-114
Author(s):  
Mitsuaki MATSUO ◽  
Takaharu TSURUTA ◽  
Gyoko NAGAYAMA
Keyword(s):  
Liquid Film ◽  
Solid Surface ◽  
Thin Liquid Film

Theoretical modeling for laser cleaning of micro-particles from solid surface

1997 ◽  
Vol 501 ◽  
Author(s):  
Y. F. Lu ◽  
W. D. Song ◽  
M. H. Hong ◽  
D. S. H. Chan ◽  
T. S. Low
Keyword(s):  
Thermal Expansion ◽  
Solid Surface ◽  
Adhesion Force ◽  
Substrate Surface ◽  
Substrate Material ◽  
Laser Wavelength ◽  
Laser Cleaning ◽  
Micro Particles ◽  
Theoretical Predictions ◽  
Substrate Surfaces

ABSTRACTIn laser cleaning of micro-particles from solid surface, the adhesion force between the particles and the substrate surface and the thermal expansion of both particles and substrate play important roles in determining the threshold laser fluence. Taking Van der Waals force and cleaning force due to fast thermal expansion of particles and substrate surface induced by pulsed laser irradiation into account, a cleaning model was established for removal of tiny particles from substrate surfaces. The cleaning condition and cleaning threshold can be obtained from this model. This model can qualitatively and quantitatively predict how the laser cleaning process depending on laser incident direction, laser wavelength, particle size, particle material and substrate material. Theoretical predictions have been verified by the experimental results. Laser cleaning of micro-particle has wide applications in microelectronics and magnetic recording industries.

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