Nonlinear deformation of a ferrofluid droplet in a uniform magnetic field.

نویسندگان

  • Gui-Ping Zhu
  • Nam-Trung Nguyen
  • R V Ramanujan
  • Xiao-Yang Huang
چکیده

This paper reports experimental and numerical results of the deformation of a ferrofluid droplet on a superhydrophobic surface under the effect of a uniform magnetic field. A water-based ferrofluid droplet surrounded by immiscible mineral oil was stretched by a magnetic field parallel to the substrate surface. The results show that an increasing flux density increases the droplet width and decreases the droplet height. A numerical model was established to study the equilibrium shape of the ferrofluid droplet. The governing equations for physical fields, including the magnetic field, are solved by the finite volume method. The interface between the two immiscible liquids was tracked by the level-set method. Nonlinear magnetization was implemented in the model. Comparison between experimental and numerical results shows that the numerical model can predict well the nonlinear deformation of a ferrofluid droplet in a uniform magnetic field.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Numerical Modeling of Ferrofluid Droplets in Magnetic Fields

Abstract. The motion and shape of a ferrofluid droplet placed in a non-magnetic viscous fluid and driven by a magnetic field are modeled numerically. The governing equations are the Maxwell equations, momentum equation and incompressibility. The numerical simulation uses a volume-of-fluid algorithm with a continuum-surface-force formulation for an axisymmetric geometry. The deformations in the ...

متن کامل

Direct Numerical Simulation of Ferrofluid Drops in a Cylindrical Microfluidic under the Influence of a Non-uniform Magnetic Field

Ferrofluids are magnetic liquids comprised of magnetic nanoparticles coated with surfactants and suspended in a carrier fluid. With biomedical and pharmaceutical applications in mind, we study the motion and deformation of axisymmetric ferrofluid droplets in the presence of non-uniform magnetic fields. Here we carry out direct numerical simulations of interfacial dynamics of ferrofluid droplet ...

متن کامل

Rapid mixing of Newtonian and non-Newtonian fluids in a three-dimensional micro-mixer using non-uniform magnetic field

The mixing of Newtonian and non-Newtonian fluids in a magnetic micro-mixer was studied numerically using  ferrofluid. The mixing process was performed in a three-dimensional steady-state micro-mixer. A magnetic source was mounted at the entrance of the micro-channel to oscillate the magnetic particles. The effects of electric current, inlet velocity, size of magnetic particles, and non-Newtonia...

متن کامل

Droplet Merging on a Lab-on-a-Chip Platform by Uniform Magnetic Fields

Droplet microfluidics offers a range of Lab-on-a-chip (LoC) applications. However, wireless and programmable manipulation of such droplets is a challenge. We address this challenge by experimental and modelling studies of uniform magnetic field induced merging of ferrofluid based droplets. Control of droplet velocity and merging was achieved through uniform magnetic field and flow rate ratio. C...

متن کامل

Dynamics of ferrofluid drop deformations under spatially uniform magnetic fields

We systematically study the shape and dynamics of a Newtonian ferrofluid drop immersed in an immiscible, Newtonian and non-magnetic viscous fluid under the action of a uniform external magnetic field. We obtain the exact equilibrium drop shapes for arbitrary ferrofluids, characterize the extent of deviations of the exact shape from the commonly assumed ellipsoidal shape, and analyse the smoothn...

متن کامل

ذخیره 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 نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Langmuir : the ACS journal of surfaces and colloids

دوره 27 24  شماره 

صفحات  -

تاریخ انتشار 2011