Dynamics of the Gas Bubbles in the Magnetic Fluid in the Non-Uniform Magnetic Field

Abstract

Abstract This work presents a study of the hydrodynamics of gas bubbles in a magnetic fluid which is in a flat channel with a thickness of 2 mm, placed in the non-uniform field of the rare-earth annular permanent magnet. The peculiarity of the magnetic field configuration of this magnet is as follows: at a distance of 9 mm from the surface of the magnet there are two symmetric regions where the magnetic field is zero, the so-called ‘magnetic vacuum’ regions. The specified configuration of the magnetic field allows capturing and holding gas cavities when the magnet moves; while pressing the cavity to the bottom of the channel, gas bubbles separate. An experimental setup was created to study the hydrodynamics of gas inclusions; using this setup studies on the concentration series of four magnetic fluids based on kerosene with a volume concentration of 10.56 %; 6.32 %; 3.93 % and 2.08% were conducted. The mechanism of gas bubbles capturing and gas cavity formation in a magnetic fluid in the magnetic vacuum region of an annular magnet is investigated. The process of the separation of the bubbles from the air cavity when it is pressed down to the bottom of the channel by a non-uniform magnetic field is studied.