Rayleigh-Bénard convection in liquid metals

Thermal turbulence at low Prandtl numbers is important for understanding stars, planets, and has great relevance to industrial silicon crystal growth, in the solidification of metallic castings, the application of liquid metals for high temperature heat exchangers, and for absorbers of concentrated solar radiation in solar power plants. Experiments with the lowest Prandtl numbers can only be realized with liquid metals and represent a great challenge. In the department of magnetohydrodynamics these liquid metal convections as well as their interaction with magnetic fields are investigated experimentally. With a targeted use of ultrasonic Doppler velocimetry (UDV) as well as non-contact CIFT measurement techniques, the complex velocity fields in the liquid metal can be reconstructed. The velocity measurements are complemented by high temporal resolution temperature measurements. This allows the global scaling for the heat transport (Nußelt number) as well as the flow intensity (Reynolds number) to be determined.

Projects:

• Turbulent convection in liquid metals ant large Rayleigh numbers (DFG-Projekt VO 2332/1-1)
• Experimental investigation of superstructures in turbulent liquid metal convection (DFG-Projekt VO 2332/3-1)
• Flow structure and heat transport in vertical convection at low Prandtl numbers (DFG-Projekt VO 2332/4-1)

Publications:

• F. Schindler, S. Eckert, T. Zürner, J. Schumacher and T. Vogt,
  Collapse of coherent large-scale flow in strongly turbulent liquid metal convection.
  Phys. Rev. Lett. (2022, in press)
• M. Akashi, T. Yanagisawa, A. Sakuraba, F. Schindler, S. Horn, T. Vogt and S. Eckert,
  Jump rope vortex flow in liquid metal Rayleigh–Bénard convection in a cuboid container of aspect ratio Γ = 5,
  J. Fluid. Mech. 932, A27 (2022)
• L. Zwirner, M.S. Emran, F. Schindler, S. Singh, S. Eckert, T. Vogt and O. Shishkina,
  Dynamics and length scales in vertical convection of liquid metals,
  J. Fluid. Mech. 932, A9 (2022)
• T. Vogt, J.C. Yang and S. Eckert,
  Free-fall velocities and heat transport enhancement in liquid metal magneto-convection,
  J. Fluid. Mech. 915, A68 (2021)
• T. Vogt, S. Horn and J.M. Aurnou,
  Oscillatory thermal–inertial flows in liquid metal rotating convection,
  J. Fluid. Mech. 915, A5 (2021)
• J.C. Yang, T. Vogt and S. Eckert,
  Transition from steady to oscillating convection rolls in Rayleigh-Bénard convection under the influence of a horizontal magnetic field,
  Phys. Rev. Fluids 6(2) (2021)
• T. Zürner, F. Schindler, T. Vogt, S. Eckert and J. Schumacher,
  Flow regimes of Rayleigh- Bénard convection in a vertical magnetic field,
  J. Fluid. Mech. 894, A21 (2020)
• P Jüstel, S Röhrborn, P Frick, V Galindo, T Gundrum, F Schindler, F. Stefani, R. Stepanov and T. Vogt,
  Generating a tide-like flow in a cylindrical vessel by electromagnetic forcing,
  Phys. Fluids 32 (9) 097105 (2020)
• T. Wondrak, V. Galindo, F. Stefani, F. Schindler, T. Vogt and S. Eckert,
  Contactless inductive flow tomography for a Rayleigh-Bénard setup with aspect ratio 0.5,
  Magnetohydrodynamics 56 (2020)
• T. Zürner, F. Schindler, T. Vogt, S. Eckert and J. Schumacher,
  Combined measurement of velocity and temperature in liquid metal convection,
  J. Fluid. Mech. 876, 1108-1128 (2019)
• M. Akashi, T. Yanagisawa, Y. Tasaka, T. Vogt, Y. Murai, S. Eckert,
  Transition from convection rolls to large-scale cellular structures in turbulent Rayleigh-Bénard convection in a liquid metal layer,
  Phys. Rev. Fluids 4(3) (2019)
• T. Vogt, S. Horn, A.M. Grannan and J.M. Aurnou,
  Jump rope vortex in liquid metal convection,
  PNAS 115(50) 12674–12679 (2018)
• T. Vogt, W. Ishimi, T. Yanagisawa, Y. Tasaka, A. Sakuraba and S. Eckert,
  Transition between quasi 2D and 3D Rayleigh-Bénard convection in a horizontal magnetic field,
  Phys. Rev. Fluids 3 (2018) 013503
• J.M. Aurnou, V. Bertin, A.M. Grannan, S. Horn and T. Vogt,
  Rotating thermal convection in liquid gallium: multi-modal flow, absent steady columns,
  J. Fluid Mech. 846, 846–876 (2018)
• T. Zürner, T. Vogt, C. Resagk, S. Eckert and J. Schumacher,
  Local Lorentz force and ultrasound Doppler velocimetry in a vertical convection liquid metal flow,
  Experiments in Fluids 59 (1) 1-12 (2018)
• Y. Tasaka, K. Igaki, T. Yanagisawa, T. Vogt, T. Zürner and S. Eckert,
  Regular flow reversals in Rayleigh-Benard convection in a horizontal magnetic field,
  Physical Review E 93 (4) (2016) 043109