scholarly journals Droplet Rolling and Spinning in V-Shaped Hydrophobic Surfaces for Environmental Dust Mitigation

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3039
Author(s):  
Mubarak Yakubu ◽  
Bekir Sami Yilbas ◽  
Abba A. Abubakr ◽  
Hussain Al-Qahtani
Keyword(s):  
3D Printing ◽  
Water Droplet ◽  
High Speed ◽  
Recording System ◽  
Functionalized Silica ◽  
Plate Surface ◽  
Hydrophobic Surfaces ◽  
Droplet Motion ◽  
Rolling Velocity ◽  
Solution Crystallization

The motion of a water droplet in a hydrophobic wedge fixture was examined to assess droplet rolling and spinning for improved dust mitigation from surfaces. A wedge fixture composed of two inclined hydrophobic plates had different wetting states on surfaces. Droplet rolling and spinning velocities were analyzed and findings were compared with the experiments. A wedge fixture was designed and realized using a 3D printing facility and a high speed recording system was adopted to evaluate droplet motion in the wedge fixture. Polycarbonate sheets were used as plates in the fixture, and solution crystallization and functionalized silica particles coating were adopted separately on plate surfaces, which provided different wetting states on each plate surface while generating different droplet pinning forces on each hydrophobic plate surface. This arrangement also gave rise to the spinning of rolling droplets in the wedge fixture. Experiments were extended to include dust mitigation from inclined hydrophobic surfaces while incorporating spinning- and rolling droplet and rolling droplet-only cases. The findings revealed the wedge fixture arrangement resulted in spinning and rolling droplets and spinning velocity became almost 25% of the droplet rolling velocity, which agrees well with both predictions and experiments. Rolling and spinning droplet gave rise to parallel edges droplet paths on dusty hydrophobic surfaces while striations in droplet paths were observed for rolling droplet-only cases. Spinning and rolling droplets mitigated a relatively larger area of dust on inclined hydrophobic surfaces as compared to their counterparts corresponding to rolling droplet-only cases.

Sliding Dynamics of a Water Droplet On Silicon Oil Film Surface

2021 ◽  
Author(s):  
Bekir Sami Yilbas ◽  
Anwaruddin Siddiqui Mohammed ◽  
Abba Abdulhamid Abubakar ◽  
Saeed Bahatab ◽  
Hussain Al-Qahtani ◽  
...  
Keyword(s):  
Water Droplet ◽  
High Speed ◽  
Film Surface ◽  
Maximum Velocity ◽  
Optical Transmittance ◽  
Gravitational Energy ◽  
Droplet Motion ◽  
Droplet Dynamics ◽  
Oil Film ◽  
Silicon Oil

Abstract A sliding droplet over the silicon oil film is examined and the dynamics of droplet motion are explored. The solution crystallized wafer surfaces are silicon oil impregnated and the uniform thickness oil film is realized. A recording facility operating at high-speed and the tracker program are used to monitor and evaluate the droplet dynamics during droplet sliding. The sliding behavior and flow generated in the droplet fluid are predicted by adopting the experimental terms. Findings revealed that the crystallized surface possesses the texture composing of spherules and fibrils, which give rise to 132o ± 4o contact angle and 38o ± 4o hysteresis. Oil impregnation on the crystalized surface improves the optical transmittance by three times for 250 nm to 500 nm wavelength range and almost 1.5 times after 500 nm to 850 nm wavelengths of the optical spectrum. The oil rim and ridges are developed in sliding water droplet vicinity while influencing droplet motion; however, this influence is estimated as almost 12% of droplet gravitational energy change during sliding. A circulatory flow is developed inside the droplet fluid and the maximum velocity in the droplet fluid changes as the droplet location changes on the oil surface during its sliding.

scholarly journals On the mechanism of droplet rolling and spinning in inclined hydrophobic plates in wedge with different wetting states

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bekir Sami Yilbas ◽  
Mubarak Yakubu ◽  
Abba Abdulhamid Abubakar ◽  
Hussain Al-Qahtani ◽  
Ahmet Sahin ◽  
...  
Keyword(s):  
Experimental Data ◽  
High Speed ◽  
Recording System ◽  
Experimental Results ◽  
Phase Contact ◽  
Droplet Motion ◽  
3D Space ◽  
Three Phase ◽  
Tangential Momentum ◽  
Recorded Data

AbstractA water droplet rolling and spinning in an inclined hydrophobic wedge with different wetting states of wedge plates is examined pertinent to self-cleaning applications. The droplet motion in the hydrophobic wedge is simulated in 3D space incorporating the experimental data. A high-speed recording system is used to store the motion of droplets in 3D space and a tracker program is utilized to quantify the recorded data in terms of droplet translational, rotational, spinning, and slipping velocities. The predictions of flow velocity in the droplet fluid are compared with those of experimental results. The findings revealed that velocity predictions agree with those of the experimental results. Tangential momentum generated, via droplet adhesion along the three-phase contact line on the hydrophobic plate surfaces, creates the spinning motion on the rolling droplet in the wedge. The flow field generated in the droplet fluid is considerably influenced by the shear rate created at the interface between the droplet fluid and hydrophobic plate surfaces. Besides, droplet wobbling under the influence of gravity contributes to the flow inside the rolling and spinning droplet. The parallel-sided droplet path is resulted for droplet emerging from the wedge over the dusty surface.

scholarly journals High-Speed 3D Printing of High-Performance Thermosetting Polymers via Two-Stage Curing

2018 ◽  
Vol 39 (7) ◽  
pp. 1700809 ◽  
Author(s):  
Xiao Kuang ◽  
Zeang Zhao ◽  
Kaijuan Chen ◽  
Daining Fang ◽  
Guozheng Kang ◽  
...  
Keyword(s):  
3D Printing ◽  
High Speed ◽  
High Performance ◽  
Two Stage ◽  
Thermosetting Polymers

scholarly journals High-Speed 3D Printing of Millimeter-Size Customized Aspheric Imaging Lenses with Sub 7 nm Surface Roughness

2018 ◽  
Vol 30 (18) ◽  
pp. 1705683 ◽  
Author(s):  
Xiangfan Chen ◽  
Wenzhong Liu ◽  
Biqin Dong ◽  
Jongwoo Lee ◽  
Henry Oliver T. Ware ◽  
...  
Keyword(s):  
Surface Roughness ◽  
3D Printing ◽  
High Speed

scholarly journals 3D printing technologies for creating models and nozzles in an aerodynamic shock tunnel experiment

2021 ◽  
Vol 2103 (1) ◽  
pp. 012033
Author(s):  
M A Kotov ◽  
N A Monakhov ◽  
S A Poniaev ◽  
P A Popov ◽  
K V Tverdokhlebov
Keyword(s):  
3D Printing ◽  
High Speed ◽  
Additive Technologies ◽  
Structure And Properties ◽  
Dynamic Experiment ◽  
Advantages And Disadvantages ◽  
Nozzle Block ◽  
Rapid Prototyping And Manufacturing ◽  
Manufacturing Techniques ◽  
Traditional Manufacturing

Abstract The features of 3D printing method for rapid prototyping and manufacturing of models for a pulsed high-speed gas-dynamic experiment are considered. Modern additive technologies allow the production of models. The basic properties of the materials and the advantages of 3D printing methods are described. The structure and properties of the obtained models can be unattainable using traditional manufacturing techniques. The design of the wind tunnel nozzle block is considered, which provides for the production of profiled contours using 3D printing. The advantages and disadvantages of use of such units on the shock tube are considered.

scholarly journals A water droplet-cleaning of a dusty hydrophobic surface: influence of dust layer thickness on droplet dynamics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ghassan Hassan ◽  
Bekir S. Yilbas ◽  
Saeed Bahatab ◽  
Abdullah Al-Sharafi ◽  
Hussain Al-Qahtani
Keyword(s):  
Layer Thickness ◽  
Inclination Angle ◽  
Water Droplet ◽  
High Speed ◽  
Small Volume ◽  
Transition Period ◽  
Imaging System ◽  
Hydrophobic Surface ◽  
Dust Layer ◽  
Surface Inclination

Abstract Water droplet cleaning of a dusty hydrophobic surface is examined. Environmental dust are used in the experiments and cloaking velocity of a dust layer by a droplet fluid is measured and hemi-wicking conditions for the dust layer are analyzed adopting the pores media wick structure approach. A droplet motion on dusty and inclined hydrophobic surface is analyzed using a high speed digital imaging system. Influences of dust layer thickness, droplet volume, and surface inclination angle on the mechanisms of dust removal by a rolling droplet are evaluated. The findings revealed that dust cloaking velocity decreases exponentially with time. The droplet fluid can cloak the dust layer during its transition on the dusty surface. The transition period of droplet wetted length on the dusty surface remains longer than the cloaking time of the dust layer by the droplet fluid. Translational velocity of rolling droplet is affected by the dust layer thickness, which becomes apparent for small volume droplets. Small volume droplet (20 µL) terminates on the thick dust layer (150 µm) at low surface inclination angle (1°). The quantity of dust picked up by the rolling droplet increases as the surface inclination angle increases. The amount of dust residues remaining on the rolling droplet path is relatively larger for the thick dust layer (150 µm) as compared to its counterpart of thin dust layer (50 µm).

scholarly journals Current Status and Prospects of Polymer Powder 3D Printing Technologies

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2406 ◽  
Author(s):  
Yue Wang ◽  
Zhiyao Xu ◽  
Dingdi Wu ◽  
Jiaming Bai
Keyword(s):  
3D Printing ◽  
High Speed ◽  
Selective Laser Sintering ◽  
Advanced Technology ◽  
Current Status ◽  
Utilization Rate ◽  
Process Selection ◽  
Forming Mechanism ◽  
Polymer Powder ◽  
Industry Applications

3D printing technology, which greatly simplifies the manufacturing of complex parts by a two-dimensional layer-upon-layer process, has flourished in recent years. As one of the most advanced technology, polymer powder 3D printing has many advantages such as high materials utilization rate, free of support structure, great design freedom, and large available materials, which has shown great potential and prospects in various industry applications. With the launch of the Multi jet Fusion system from HP, polymer powder 3D printing has been attracting more attention from industries and researchers. In this work, a comprehensive review of the main polymer powder-based 3D printing methods including binder jetting, selective laser sintering, high-speed sintering were carried out. Their forming mechanism, advantages and drawbacks, materials, and developments were presented, compared, and discussed respectively. In addition, this paper also gives suggestions on the process selection by comparing typical equipment parameters and features of each technology.

Sign in / Sign up

Export Citation Format

Share Document