The Role of Slip and No Slip Behavior On Droplet Impingement

2021 ◽  
Author(s):  
A. R. Pati ◽  
Biswajit Swain ◽  
Soumya Sanjeeb Mohapatra
Keyword(s):  
Hydrophobic Surface ◽  
Slip Condition ◽  
Dimensionless Time ◽  
Droplet Impingement ◽  
Slip Conditions ◽  
Superhydrophilic Surface ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
The Impact

Abstract For the identification of role of slip and no slip conditions at the solid-liquid interface in case of hydrophobic, superhydrophilic and superhydrophobic surfaces, the experimentally determined velocity profiles are analysed. Before experimentation, each surface was characterized by using SEM, 2D and 3D Surface profilometer. The impact mapping results reveal that in case of hydrophobic surface, first no slip condition is achieved and then slip condition is noticed. Conversely, for superhydrophilic surface, initially slip and then no slip conditions are observed. Furthermore, in case of superhydrophobic surface, slip behaviour is observed throughout the process for the dimensionless time ranges 0.06-0.94 and this behaviour of the process promotes local enhancement of viscous and capillary forces. The experimentally obtained results are further tried to validate with the help of theoretical and visual observations.

The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham
Keyword(s):  
Mass Transfer ◽  
Cell Membrane ◽  
Substrate Concentration ◽  
Water Interface ◽  
Industrial Systems ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

Modeling and Experiments of Laser Cladding With Droplet Injection

2005 ◽  
Vol 127 (9) ◽  
pp. 978-986 ◽  
Author(s):  
J. Choi ◽  
L. Han ◽  
Y. Hua
Keyword(s):  
Fluid Flow ◽  
Laser Cladding ◽  
Dynamic Motion ◽  
Cladding Layer ◽  
Melt Pool ◽  
Material Deposition ◽  
Modeling And Experiments ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
The Impact

Laser aided Directed Material Deposition (DMD) is an additive manufacturing process based on laser cladding. A full understanding of laser cladding is essential in order to achieve a steady state and robust DMD process. A two dimensional mathematical model of laser cladding with droplet injection was developed to understand the influence of fluid flow on the mixing, dilution depth, and deposition dimension, while incorporating melting, solidification, and evaporation phenomena. The fluid flow in the melt pool that is driven by thermal capillary convection and an energy balance at the liquid–vapor and the solid–liquid interface was investigated and the impact of the droplets on the melt pool shape and ripple was also studied. Dynamic motion, development of melt pool and the formation of cladding layer were simulated. The simulated results for average surface roughness were compared with the experimental data and showed a comparable trend.

Role of the solid/liquid interface faceting in rapid penetration of a liquid phase along grain boundaries

2001 ◽  
Vol 49 (7) ◽  
pp. 1123-1128 ◽  
Author(s):  
D. Chatain ◽  
E. Rabkin ◽  
J. Derenne ◽  
J. Bernardini
Keyword(s):  
Liquid Phase ◽  
Grain Boundaries ◽  
Liquid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid

Synthesis of Cyclic Carbonates: Catalysis by an Iron-Based Composite and the Role of Hydrogen Bonding at the Solid/Liquid Interface

ChemSusChem ◽  
2012 ◽  
Vol 5 (4) ◽  
pp. 652-655 ◽  
Author(s):  
Jin Qu ◽  
Chang-Yan Cao ◽  
Zhi-Feng Dou ◽  
Hua Liu ◽  
Yu Yu ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Liquid Interface ◽  
Cyclic Carbonates ◽  
Iron Based ◽  
Solid Liquid Interface ◽  
Solid Liquid

Stability of Thermoelectromagnetic Convection

2006 ◽  
Author(s):  
Brent C. Houchens
Keyword(s):  
Numerical Solutions ◽  
Liquid Interface ◽  
Analytical And Numerical Solutions ◽  
The Stability ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Initial Results

The role of thermoelectromagnetic convection (TEMC) on the stability of a range of flows is investigated. Here we discuss the general features of TEMC, and describe experiments in which this effect is thought to have significance. The general formulation for TEMC at a solid-liquid interface is presented. Initial results are benchmarked with existing analytical and numerical solutions.

Modeling Coupled Conduction–Convection Ice Formation on Horizontal Axially Finned and Unfinned Tubes

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Hassan M. S. Al-Sarrach ◽  
Ghalib Y. Kahwaji ◽  
Mohamed A. Samaha
Keyword(s):  
Natural Convection ◽  
Liquid Interface ◽  
Ice Formation ◽  
Finite Difference Schemes ◽  
Freezing Process ◽  
Liquid Region ◽  
Water Density ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
The Impact

The freezing of water around immersed unfinned and finned horizontal tubes is simulated numerically. The impact of natural convection as well as the water density inversion with temperature is considered. The equations governing both fluid flow and heat transfer around the tubes and through the solid–liquid interface are solved using finite difference schemes. To follow the moving solid–liquid boundary, dynamic grid generation is performed using the elliptic partial differential equation method with iterative interpolating smoothing to avoid divergence. For validation, the present results for unfinned tubes are compared with experimental studies reported in the literature. The present numerical simulations are aimed at improving our understanding of the parameters affecting the freezing process around both finned and unfinned tubes. The results showed that the flow patterns are similar in both tube configurations with one main vortex in the liquid region when there is no inversion in the water density. The presence of fins complicates the distribution of local Nusselt number along the solid–liquid interface in comparison with the unfinned tube. The impact of natural convection on the rate of ice formation is limited to the initial period of the freezing process. The results also show the freezing enhancement when utilizing fins. An accumulated ice mass correlation is developed for each tube configuration. This model can be used to optimize the design of both finned and unfinned tubes in energy storage systems, which are viable tools for air conditioning load shifting and leveling.

Nanobubbles on a Very Flat Hydrophobic Surface Prepared by Self-Assembled Monolayers

2013 ◽  
Author(s):  
Takashi Nishiyama ◽  
Koji Takahashi ◽  
Yasuyuki Takata
Keyword(s):  
Heat Transfer ◽  
Gaseous Phase ◽  
Hydrophobic Surface ◽  
Bubble Nucleation ◽  
Liquid Interface ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Solid Liquid Interface ◽  
Solid Liquid

Boiling is one of the most effective heat transfer methods due to its high heat transfer coefficient. Therefore, boiling heat transfer plays a very important role for various applications in many technological and industrial areas. However, a very complex mechanism of boiling, especially bubble nucleation, is still not sufficiently understood. On the other hand, numerous experiments have revealed the existence of soft domains that called nanobubbles at the solid-liquid interface. In this study, to investigate the influence of the solid-liquid interface nanobubbles on the bubble nucleation, an atomic force microscope (AFM) is used to characterize the morphology of nanobubbles. In order to separate the effect of wettability of a solid surface from that of surface structure, a very flat hydrophobic surface was prepared. 1H,1H,2H,2H-Perfluoro-n-octylphosphonic acid (FOPA) formed the interface of hydrophobic self-assembled monolayers (SAMs). As the result of AFM measurement, many nanobubbles about 100 nm in diameter and 30 nm thick are observed at the interface of the FOPA surface and the pure water. In addition, to prove the existence of gaseous phase, the heat conductance measurement by time-domain thermoreflectance method (TDTR) was introduced. TDTR is an ultrafast optical pump probe technique well suited for thermal measurement of thin films. It enables to resolve the thermal conductivity of the thin film and the thermal conductance of the interface. If nanobubbles are the gaseous phase, the big change of interface heat thermal resistance will be seen and the TDTR signal should also change. The effectiveness of a TDTR to confirm the existence of nanobubbles is shown by the model simulation of TDTR. A clear difference is seen in TDTR signal by the existence of only 1 nm gaseous phase. After confirming the existence of nanobubbles by AFM measurement, it can be proved that the nanobubbles are truly gaseous phase of the TDTR measurement.

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