scholarly journals Contact Time of Double-Droplet Impacting Superhydrophobic Surfaces with Different Macrotextures

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 896
Author(s):  
Dian-Ji Lin ◽  
Ling-Zhe Zhang ◽  
Meng-Chao Yi ◽  
Xin Wang ◽  
Shu-Rong Gao ◽  
...  
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Contact Time ◽  
Superhydrophobic Surface ◽  
Vertical Wall ◽  
Spray Cooling ◽  
Superhydrophobic Surfaces ◽  
Geometrical Parameters ◽  
Boltzmann Method ◽  
Center Distance

The contact time of droplets on superhydrophobic surfaces is an especially important parameter in many applications, such as self-cleaning, anti-icing, and spray cooling. In this study, we investigate the contact time of two identical droplets simultaneously impacting superhydrophobic surfaces decorated with three different macrotextures, i.e., bathtub-like groove (S1), vertical wall (S2), and rectangular ridge (S3), via lattice Boltzmann method (LBM) simulations. We explore influences of the geometrical parameters of the macrotextures, as well as the center-to-center distance of the two droplets, on the contact time. We found a new rebounding regime with significantly reduced contact times. We demonstrate that, as compared with impacting a smooth superhydrophobic surface, the contact time can be decreased by 41% for macrotexture S1 because of the asymmetric spreading and retraction of droplets motivated by the macrotexture. We also demonstrate that the new regime depends on the center-to-center distance and geometrical parameters of the macrotextures.

Research on the contact time of a bouncing microdroplet with lattice Boltzmann method

2021 ◽  
Vol 33 (4) ◽  
pp. 042011
Author(s):  
Yaolin Tai ◽  
Yang Zhao ◽  
Xinyu Guo ◽  
Linan Li ◽  
Shibin Wang ◽  
...  
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Contact Time ◽  
Boltzmann Method

Multiple-relaxation-time lattice Boltzmann method of hydrodynamic lubrication in lemon-bore bearing

2017 ◽  
Vol 232 (4) ◽  
pp. 469-479 ◽  
Author(s):  
Alireza Arab Solghar
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Hydrodynamic Lubrication ◽  
Interpolation Method ◽  
Load Capacity ◽  
Linear Interpolation ◽  
Geometrical Parameters ◽  
Comparison Of The Results ◽  
Ellipticity Ratio ◽  
Boltzmann Method

The lattice Boltzmann method has superiority over conventional computational fluid dynamics methods, particularly for the flow simulations in complex geometries. In the present work, the performance of hydrodynamic lemon-bore (elliptical) journal bearings was investigated with the implementation of the lattice Boltzmann method. The steady-state laminar flow of a homogeneous oil was considered in the computations. A linear interpolation method was exploited to obtain the surface curvatures. The comparison of the results obtained from the proposed methodology with available literature data showed a satisfactory agreement. The effect of geometrical parameters on the hydrodynamic lubrication in an elliptical journal bearing was analyzed. It was found that the ellipticity ratio has profound effects on the bearing load capacity, oil flow rate and bearing power loss.

Numerical Study of Pool Boiling Heat Transfer From Surface With Protrusions Using Lattice Boltzmann Method

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Kaushik Mondal ◽  
Anandaroop Bhattacharya
Keyword(s):  
Heat Transfer ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Boiling Heat Transfer ◽  
Plane Surface ◽  
Pool Boiling ◽  
Geometrical Parameters ◽  
Maximum Heat ◽  
Pool Boiling Heat Transfer ◽  
Boltzmann Method

Abstract This paper reports our numerical studies on pool boiling heat transfer from a plane and with protruding surface using single component pseudo-potential phase change model of lattice Boltzmann method. The surface protrusions are assumed to be rectangular in shape with a given height and width. The surface protrusions are seen to promote nucleation of bubbles from the heated surface resulting in significantly higher heat transfer rates compared to the plane surface. Spatial and temporal averaged heat fluxes from all these protruding surfaces are found to be 3–4 times higher than that of a plane surface. The effects of the protrusion height, width, spacing, and associated geometrical parameters on surface heat flux have been investigated in order to arrive at an optimal design for maximum heat transfer.

Computational analysis of magneto-hydrodynamic natural convection in partially differentially heated cavity: Effect of cooler size

2018 ◽  
Vol 232 (3) ◽  
pp. 515-528 ◽  
Author(s):  
Krunal M Gangawane ◽  
Ram P Bharti
Keyword(s):  
Nusselt Number ◽  
Rayleigh Number ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Average Nusselt Number ◽  
Hartmann Number ◽  
Vertical Wall ◽  
Vertical Direction ◽  
Wide Range ◽  
Boltzmann Method

This work presents thermal lattice Boltzmann method simulation of magneto-hydrodynamic, buoyancy-driven convection in a partially differentially heated cavity (aspect ratio = 1) subjected to a magnetic field along the vertical direction, i.e. at 90°. Lattice Boltzmann method simulations are performed for three different cooler lengths (Lc = H/4, H/2, H) placed along the middle of one vertical wall for a wide range of Rayleigh and Hartmann numbers (103 ≤ Ra ≤ 105; Ha = 0, 60, 120) at fixed Prandtl number (Pr = 0.71, air). A partial heater is placed at the center of other vertical walls and its size is kept as half of the characteristic length (H/2). The physical insights of the systems are delineated by systematic analysis of stream function and temperature contours. Heat transfer characteristics of the cavity are elucidated by using averaged values of the Nusselt number. It is noted that average Nusselt number has a proportional dependence with cooler length and Rayleigh number, while it varied inversely with Hartmann number. Further, the functional dependence of average Nusselt number with cooler size, Rayleigh number, and Hartmann number is established for possible use in engineering design purpose.

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