Dynamics of liquid films exposed to high-frequency surface vibration.
نویسندگان
چکیده
We derive a generalized equation that governs the spreading of liquid films under high-frequency (MHz-order) substrate vibration in the form of propagating surface waves and show that this single relationship is universally sufficient to collectively describe the rich and diverse dynamic phenomena recently observed for the transport of oil films under such substrate excitation, in particular, Rayleigh surface acoustic waves. In contrast to low-frequency (Hz- to kHz-order) vibration-induced wetting phenomena, film spreading at such high frequencies arises from convective drift generated by the viscous periodic flow localized in a region characterized by the viscous penetration depth β(-1)≡(2μ/ρω)(1/2) adjacent to the substrate that is invoked directly by its vibration; μ and ρ are the viscosity and the density of the liquid, respectively, and ω is the excitation frequency. This convective drift is responsible for driving the spreading of thin films of thickness h≪k(l)(-1), which spread self-similarly as t(1/4) along the direction of the drift corresponding to the propagation direction of the surface wave, k(l) being the wave number of the compressional acoustic wave that forms in the liquid due to leakage of the surface wave energy from the substrate into the liquid and t the time. Films of greater thicknesses h∼k(l)(-1)≫β(-1), in contrast, are observed to spread with constant velocity but in a direction that opposes the drift and surface wave propagation due to the attenuation of the acoustic wave in the liquid. The universal equation derived allows for the collective prediction of the spreading of these thin and thick films in opposing directions.
منابع مشابه
Simulation of Fabrication toward High Quality Thin Films for Robotic Applications by Ionized Cluster Beam Deposition
The most commonly used method for the production of thin films is based on deposition of atoms or molecules onto a solid surface. One of the suitable method is to produce high quality metallic, semiconductor and organic thin film is Ionized cluster beam deposition (ICBD), which are used in electronic, robotic, optical, optoelectronic devices. Many important factors such as cluster size, cluster...
متن کاملVibrational lifetimes of hydrogen on lead films: an ab initio molecular dynamics with electronic friction (AIMDEF) study.
Using density functional theory and Ab Initio Molecular Dynamics with Electronic Friction (AIMDEF), we study the adsorption and dissipative vibrational dynamics of hydrogen atoms chemisorbed on free-standing lead films of increasing thickness. Lead films are known for their oscillatory behaviour of certain properties with increasing thickness, e.g., energy and electron spillout change in discon...
متن کاملVibration Suppression of Fuel Sloshing using Subband Adaptive Filtering (RESEARCH NOTE)
One of the main vibration problems of aerospace vehicles with liquid fuel propulsion system is fuel sloshing. This phenomenon is a low frequency vibrational challenge which can affect the motion of the vehicle and degrade the stability of the main control system. In this regards, the motion of the liquid will be very critical when the frequency of the sloshing is very close to the frequencies o...
متن کاملar X iv : c on d - m at / 9 70 60 58 v 1 6 J un 1 99 7 Dynamics of Viscous Amphiphilic Films Supported by Elastic Solid Substrates
The dynamics of amphiphilic films deposited on a solid surface is analyzed for the case when shear oscillations of the solid surface are excited. The two cases of surface-and bulk shear waves are studied with the film exposed to gas or to a liquid. By solving the corresponding dispersion equation and the wave equation while maintaining the energy balance we are able to connect the surface densi...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review. E, Statistical, nonlinear, and soft matter physics
دوره 91 5 شماره
صفحات -
تاریخ انتشار 2015