Surface instability of paramagnetic liquid in non-uniform magnetic field

Research output: Contribution to journalConference articleContributedpeer-review

Contributors

  • Barbara Fritzsche - , Chair of Transport Processes at Interfaces (Author)
  • Gerd Mutschke - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Till J. Meinel - , TUD Dresden University of Technology, Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Xuegeng Yang - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Zhe Lei - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Kerstin Eckert - , Chair of Transport Processes at Interfaces, Helmholtz-Zentrum Dresden-Rossendorf (Author)

Abstract

Aqueous solutions of rare earth salts are an important class of paramagnetic liquids. Such liquids can be manipulated by external magnetic fields in a contactless manner and free of Joule heating. This is of particular interest for the magnetic separation of the paramagnetic rare earth ions out of this solution. If the paramagnetic liquid possesses a free surface, an inhomogeneous magnetic field leads unavoidably to a deformation of this surface. Unlike super-paramagnetic liquids, e.g. ferrofluids, the dynamics of such deformations is less studied. To observe the combined effect of gravity and magnetic field on paramagnetic solutions, a permanent magnet was moved vertically above the free surface of DyCl3 and MnSO4 solution. The deformation of the interface was followed optically by shadowgraphy, and studied for different concentrations and speeds by which the magnet is applied and removed. The speed of the moving magnet falls into two categories: (i) a quasi-static and (ii) a jump-like magnetization and demagnetization. It was found, that the interface of the liquid is oscillating with a specific frequency which is defined by the concentration of the solution, independently of the magnet velocity.

Details

Original languageEnglish
JournalProceedings of the International Astronautical Congress, IAC
Volume2018-October
Publication statusPublished - 2018
Peer-reviewedYes

Conference

Title69th International Astronautical Congress: #InvolvingEveryone, IAC 2018
Duration1 - 5 October 2018
CityBremen
CountryGermany

Keywords

Keywords

  • Non-uniform magnetic field, Paramagnetic liquid, Shadowgraph, Surface instability