Instabilities and spin-up behaviour of a rotating magnetic field driven flow in a rectangular cavity

Galindo, Vladimir; Nauber, Richard; Räbiger, D.; Franke, Sven; Beyer, Hannes; Büttner, Lars; Czarske, Jürgen; Eckert, Sven

doi:10.1063/1.4993777

Cited by 11 publications

(7 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The pulsation frequency almost does not affect spin-up time. Fluctuations after spin-up time can be explained by the rectangular shape of vessel [24,25].…”

Section: Spin-up Behaviourmentioning

confidence: 99%

Liquid Metal Flow Under Traveling Magnetic Field—Solidification Simulation and Pulsating Flow Analysis

Shvydkiy

Baake

Köppen

2020

Metals

View full text Add to dashboard Cite

Non steady applied magnetic field impact on a liquid metal has good prospects for industry. For a better understanding of heat and mass transfer processes under these circumstances, numerical simulations are needed. A combination of finite elements and volumes methods was used to calculate the flow and solidification of liquid metal under electromagnetic influence. Validation of numerical results was carried out by means of measuring with ultrasound Doppler velocimetry technique, as well as with neutron radiography snapshots of the position and shape of the solid/liquid interface. As a result of the first part of the work, a numerical model of electromagnetic stirring and solidification was developed and validated. This model could be an effective tool for analyzing the electromagnetic stirring during the solidification process. In the second part, the dependences of the velocity pulsation amplitude and the melt velocity maximum value on the magnetic field pulsation frequency are obtained. The ability of the pulsating force to develop higher values of the liquid metal velocity at a frequency close to the MHD resonance was found numerically. The obtained characteristics give a more detailed description of the electrically conductive liquid behaviour under action of pulsating traveling magnetic field.

show abstract

“…The pulsation frequency almost does not affect spin-up time. Fluctuations after spin-up time can be explained by the rectangular shape of vessel [24,25].…”

Section: Spin-up Behaviourmentioning

confidence: 99%

Liquid Metal Flow Under Traveling Magnetic Field—Solidification Simulation and Pulsating Flow Analysis

Shvydkiy

Baake

Köppen

2020

Metals

View full text Add to dashboard Cite

show abstract

“…Spin-up time for the near-wall area reaches 2-4 seconds, while in the central area flow needs 10-20 seconds to reach working velocity. Fluctuations after spin-up time can be explained by the rectangular shape of vessel [21,22].…”

Section: Spin Up Behaviourmentioning

confidence: 99%

Liquid Metal Flow under Traveling Magnetic Field: Solidification Simulation and Pulsating Flow Analysis

Shvydkiy¹,

Baake²,

Köppen³

2020

Preprint

View full text Add to dashboard Cite

Non steady applied magnetic field impact on a liquid metals has good prospects for industry. For a better understanding of heat and mass transfer processes under these circumstances, numerical simulations are needed. A combination of finite elements and volumes methods was used to calculate the flow and solidification of liquid metal under electromagnetic influence. Validation of numerical results was carried out by means of measuring with ultrasound Doppler velocimetry technique, as well as with neutron radiography snapshots of the position and shape of the solid/liquid interface. As a result of the first part of the work, a numerical model of electromagnetic stirring and solidification was developed and validated. This model could be an effective tool for analyzing the electromagnetic stirring during the solidification process. In the second part, the dependences of the velocity pulsation amplitude and the melt velocity maximum value on the magnetic field pulsation frequency are obtained. It was found numerically the ability of the pulsating force action to develop higher values of the liquid metal velocity at a frequency close to the MHD resonance. Obtained characteristics give a more detailed description of the electrically conductive liquid behaviour under action of pulsating traveling magnetic field.

show abstract

“…Influence of the spatial resolution from the finite width of the sound field Type B estimation for a beam width x = 3 mm and typical velocity gradients of MHD experiments estimated from numerical simulation; dv dx = 0.16 mm −1 • v max (Galindo et al, 2017);…”

Section: Number Of Repetitionsmentioning

confidence: 99%

“…-Long measurement duration -flow phenomena on different timescales should be adequately captured; for instance, rapid spontaneous changes of the flow regime in a rotating flow (Galindo et al, 2017) or in multihour model experiments of the semiconductor crystallization process (Thieme et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Measurement uncertainty analysis of field-programmable gate-array-based, real-time signal processing for ultrasound flow imaging

Nauber

Büttner

Czarske

2020

J. Sens. Sens. Syst.

Self Cite

View full text Add to dashboard Cite

Abstract. Research in magnetohydrodynamics (MHD) aims to understand the complex interactions of electrically conductive fluids and magnetic fields. A promising approach for investigating complex instationary flow phenomena are lab-scale experiments with low-melting alloys. They require a noninvasive flow instrumentation for opaque liquids with a high spatiotemporal resolution, a low velocity uncertainty and a long measurement duration. Ultrasound Doppler velocimetry can achieve multiplane, multicomponential flow imaging with multiple linear ultrasound arrays. However the average raw data output amounts to 1.2 GBs−1 at a frame rate of 33 Hz in a typical configuration for 200 transducers. This usually prevents long-duration measurements when offline signal processing is used. In this paper, we propose an online signal-processing chain for pulsed-wave Doppler velocimetry that is tailored to the specific requirements of flow imaging for lab-scale experiments. The trade-off between measurement uncertainty and computational complexity is evaluated for different algorithmic variants in relation to the Cramér–Rao bound. By utilizing selected approximations and parameter choices, a prepossessing could be efficiently implemented on a field-programmable gate array (FPGA), enabling a typical reduction of the data bandwidth of 6.5:1 and online flow visualization. We validated the performance of the signal processing on a test rig, yielding a velocity standard deviation that is a factor of 3 above the theoretical limit despite a low computational complexity. Potential applications for this signal processing include multihour flow measurements during a crystal-growth process and closed-loop velocity feedback for model experiments.

show abstract

Instabilities and spin-up behaviour of a rotating magnetic field driven flow in a rectangular cavity

Cited by 11 publications

References 26 publications

Liquid Metal Flow Under Traveling Magnetic Field—Solidification Simulation and Pulsating Flow Analysis

Liquid Metal Flow Under Traveling Magnetic Field—Solidification Simulation and Pulsating Flow Analysis

Liquid Metal Flow under Traveling Magnetic Field: Solidification Simulation and Pulsating Flow Analysis

Measurement uncertainty analysis of field-programmable gate-array-based, real-time signal processing for ultrasound flow imaging

Contact Info

Product

Resources

About