Experimental Study for Movement of Liquid Drop on the Surface with Gradient Surface Energy

2006 ◽  
Author(s):  
Qiang Liao ◽  
Hong Wang ◽  
Xun Zhu ◽  
Biao Gu
Keyword(s):  
Experimental Study ◽  
Surface Energy ◽  
Liquid Drop ◽  
Gradient Surface

Deformation of metallic liquid drop by electric field for contacts in molecular–organic electronics

2009 ◽  
Vol 465 (2106) ◽  
pp. 1799-1808 ◽  
Author(s):  
M. Bag ◽  
D. Gupta ◽  
N. Arun ◽  
K.S. Narayan
Keyword(s):  
Solid State ◽  
Surface Energy ◽  
Electric Field ◽  
Linear Response ◽  
Liquid Drop ◽  
Electrostatic Energy ◽  
Critical Voltage ◽  
Metallic Liquid ◽  
Linear Response Regime ◽  
Polymer Electronics

We study and use the behaviour of a metallic liquid drop in the presence of an external electric field (EF). The droplet profile is governed by the stabilizing surface energy and the destabilizing electrostatic energy, with a critical voltage beyond which the droplet becomes unstable. We explore the EF-induced behaviour of low melting temperature alloy in the liquid state and observe that the droplet modifications in the linear response regime can be retained upon cooling the drop to the solid state. We demonstrate that this procedure can be used as an electrode with precise dimensions for applications in molecular and polymer electronics.

Surface Energy Driven Liquid-Drop-Like Pseudoelastic Behaviors and In Situ Atomistic Mechanisms of Small-Sized Face-Centered-Cubic Metals

Nano Letters ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 292-298 ◽  
Author(s):  
Deli Kong ◽  
Tianjiao Xin ◽  
Shiduo Sun ◽  
Yan Lu ◽  
Xinyu Shu ◽  
...  
Keyword(s):  
Surface Energy ◽  
Liquid Drop ◽  
Face Centered Cubic ◽  
Cubic Metals ◽  
Face Centered

Equilibrium of liquid drops under the effects of rotation and acoustic flattening: results from USML-2 experiments in Space

1998 ◽  
Vol 354 ◽  
pp. 43-67 ◽  
Author(s):  
C. P. LEE ◽  
A. V. ANILKUMAR ◽  
A. B. HMELO ◽  
T. G. WANG
Keyword(s):  
Experimental Study ◽  
Angular Velocity ◽  
Liquid Drop ◽  
Sound Field ◽  
Theoretical Models ◽  
Liquid Drops ◽  
Complementary Effect ◽  
Rotating Liquid ◽  
Neutral Equilibrium ◽  
Effects Of Rotation

Previous Space-based experiments (Wang et al. 1994a) showed that a rotating liquid drop bifurcates into a two-lobed shape at a lower critical angular velocity, if it is flattened acoustically by the leviating sound field. In this work, we undertake a systematic experimental study of the effect of acoustic flattening on the rotational bifurcation of a liquid drop. We also look into the complementary effect of rotation on the equilibrium of an acoustically drastically flattened drop. Theoretical models are developed for each of the two effects and then woven into a unified picture. The first effect concerns neutral equilibrium, while the second concerns loss of equilibrium, neither of them involving instability. The theories agree well with the experiments.

Experimental study of the oscillations of a rotating drop

1985 ◽  
Vol 158 ◽  
pp. 317-327 ◽  
Author(s):  
P. Annamalai ◽  
E. Trinh ◽  
T. G. Wang
Keyword(s):  
Experimental Study ◽  
Analytical Study ◽  
Liquid Drop ◽  
Angular Speed ◽  
Immiscible Fluid ◽  
Drop Shape ◽  
Free Decay ◽  
Resonance Frequencies ◽  
Rotating Liquid ◽  
Relative Change

Two- and three-lobed oscillations of a rotating liquid drop immersed in an immiscible fluid of comparable density and the same angular velocity were studied experimentally. Using acoustically suspended drops, it has been found that the relative change in the resonance frequencies of the axisymmetric drop-shape oscillations Δωl/ωl(0) is proportional to the square of the normalized angular speed (Ω/ωl(0))2 when ωl > 2Ω. This is in agreement with a recent analytical study of the same problem. Some preliminary results regarding the effect of rotation on the free-decay rate of the two-lobed oscillations are also presented.

Shattering of a liquid drop due to impact

1991 ◽  
Vol 435 (1895) ◽  
pp. 483-503 ◽  
Keyword(s):  
Surface Energy ◽  
Statistical Model ◽  
Surface Area ◽  
Liquid Drop ◽  
Drop Impact ◽  
Drop Breakup ◽  
Viscous Effects ◽  
Consistent Manner

Based on energy and entropy principles, a statistical model describing the shattered state of a single spherical liquid drop after being subjected to a relatively sudden but uniform (over the whole surface area of the drop) impact is developed. The problem is addressed from a fundamental standpoint, with the intention of providing a predictive framework for the various modes of breakup and the size and number of droplets produced. Upon neglecting viscous effects, several results in terms of the energy of impact, non-dimensionalized with respect to the surface energy of the drop before impact, are derived. The model is quite simple and straightforward, yet it appears to predict in a fairly consistent manner certain experimental observations that have been made repeatedly in relation to drop breakup in stirred dispersions, by collision, and exposure to shocks.

Experimental Study on Frost Structure on Surfaces With Different Hydrophilicity: Density and Thermal Conductivity

2003 ◽  
Vol 125 (1) ◽  
pp. 84-94 ◽  
Author(s):  
Jongmin Shin ◽  
Alexei V. Tikhonov ◽  
Cheolhwan Kim
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Surface Energy ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Test Time ◽  
Visualization System ◽  
Conductivity Increase ◽  
Deposition Density ◽  
Frost Layer

An experimental study has been conducted to investigate the effects of surface energy on frost formation. Test samples with three different surfaces of which dynamic contact angles (DCA) were 23, 55, and 88 deg were installed in a wind tunnel and exposed to a humid airflow. The airflow Reynolds number, humidity, the air and the cold plate temperatures were maintained at 9000, 0.0042 kg/kg′, +12 and −22°C, respectively. The thickness and the mass of frost layer were measured and used to calculate frost density while heat flux and temperature profile were measured to obtain thermal conductivity. Exact positions of thermocouple junctions were verified by means of visualization system in order to increase accuracy. Results showed that frost density and thermal conductivity increase with time. The surface with a lower DCA showed a higher frost density and thermal conductivity during a two-hour test, but minor differences have been found after two hours of frost generation. Empirical correlations for thickness, mass deposition, density and thermal conductivity were proposed as the functions of test time and surface energy.

Impact of Drops on Various Non-Wetting Surfaces

2009 ◽  
Author(s):  
Philippe Brunet ◽  
Alain Merlen
Keyword(s):  
Experimental Study ◽  
Contact Angle ◽  
Thin Layer ◽  
Initial Velocity ◽  
Liquid Drop ◽  
Spray Cooling ◽  
Lateral Extension ◽  
Hot Plate ◽  
Boiling Crisis ◽  
Leidenfrost Effect

We have carried out an experimental study of liquid drop impact on various superhydrophobic substrates. Our surfaces are of two kinds (1) a carpet of chemically coated nanowires and (2) a smooth warm substrate. In the latter case, the Leidenfrost effect (also called ‘boiling crisis’) ensures the existence of a thin layer of air coming from the evaporation of the drop, thus preventing the drop to touch the warm surface. Technically, in this latter situation the contact angle can then be considered as equal to 180 degrees, with no hysteresis. Due to its initial inertia, the drop experiences a flattening phase after it hits the surface, taking the shape of a pancake. Once it reaches its maximal lateral extension, the drop begins to retract and bounces back. We have extracted the lateral extension of the drop, and we propose a model that explains the trend. We find a limit initial velocity beyond which the drop (1) protrudes into the nanowire carpet (2) touches the hot plate, provoking a local violent boiling. We discuss the relevance of practical issues in terms of self-cleaning surfaces or spray-cooling.

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