A RANS numerical model for calibration of Lorentz force flowmeter applying to metallugy industry. - In: 23rd International Congress of Theoretical and Applied Mechanics, 2012, FM11-002, insges. 2 S.
We present a RANS numerical model for calibrating LFF. Two common metallurgy industry flow types: duct flow and open-channel flow have been studied with this model. For duct flow, the computing calibration constant demonstrates coincide with accuracy of 3.4% with an experimental model. For open-channel flow, a multiphase model is built to take free surface into account. The free surface deformation, magnetic field optimization and characteristics of the realistic flow in an open channel can be simulated by this numerical model.
Deflection of laminar liquid metal flow by a magnetic point dipole. - In: 23rd International Congress of Theoretical and Applied Mechanics, 2012, FM11-006, insges. 2 S.
We study distortion of laminar liquid metal flow by a magnetic point dipole in a straight square duct. This basic configuration is of fundamental interest for Lorentz force velocimetry, where the Lorentz force opposing the relative motion of conducting medium and magnetic field is measured to determine the flow velocity. The total force is highly dependent on the velocity profile, which changes its shape due to the acting Lorentz force itself. We are interested in the deflection of the flow and its dependence on magnitude and distribution of the magnetic field. To this end, we perform direct numerical simulations with an accurate finite-difference scheme in the limit of small magnetic Reynolds numbers. The hydrodynamic Reynolds number is choosen to be high enough to allow the generation of vortices and turbulent structures.
Noncontact electromagnetic flow measurement in electrolytes. - In: 23rd International Congress of Theoretical and Applied Mechanics, 2012, FM11-005, insges. 2 S.
Lorentz force velocimetry (LFV) is a noncontact electromagnetic flow measurement technique that is currently successfully applied for velocity measurements in liquid metals both in laboratory experiments and industry. However, up to now the application of LFV was restricted to conducting fluids with electrical conductivities of the order of 106 S/m such as are encountered in liquid metals. Here we demonstrate that LFV can be successfully extended to poorly conducting fluids (electrolytes) by using high-resolution force measurements.
Boundary layer visualization in turbulent Rayleigh-Bénard convection in air. - In: 23rd International Congress of Theoretical and Applied Mechanics, 2012, FM05-004, insges. 2 S.
We present results of boundary layer flow visualization in turbulent Rayleigh-Bénard (RB) convection in air at Rayleigh number of Ra=1.4 x 1010. The experiments have been performed in a slender rectangular test cell with the dimensions of 2.5 m x 2.5 m x 0.6 m. The cell was installed in our large-scale RB experiment 'Barrel of Ilmenau' using its uniformly tempered heating and cooling plates as bottom and top bound of the small cell. Highly resolved movies as well as single frames of the boundary layer flow have been captured at various positions above the heating plate. They show that the idea of a basically laminar boundary layer does not hold at low Prandtl and moderate Rayleigh numbers.
Lorentz force eddy current testing: a prototype model. - In: Journal of nondestructive evaluation, ISSN 1573-4862, Bd. 31 (2012), 4, S. 357-372
We report an investigation of the motion of a freefalling permanent magnet in an electrically conducting pipe containing an idealized defect. This problem represents a highly simplified yet enlightening version of a method called Lorentz force eddy current testing which is a modification of the traditional eddy current testing technique. Our investigation is a combination of analytical theory, numerical simulation and experimental validation. The analytical theory allows a rigorous prediction about the relation between the size of the defect and the change in falling time which represents the central result of the present work. The numerical simulation allows to overcome limitations inherent in the analytical theory. We test our predictions by performing a series of experiments. We conclude that our theory properly captures the essence of Lorentz force eddy current testing although a refinement of the experiment is necessary to reduce the discrepancy to the predictions. In spite of its apparent simplicity the present system can serve as a prototype and benchmark for future research on Lorentz force eddy current testing.
http://dx.doi.org/10.1007/s10921-012-0147-7
Experimental study and numerical visualization of physical fields of electromagnetic pumps constructed on permanent magnets. - In: Journal of iron and steel research international, ISSN 1006-706X, Bd. 19.2012, Suppl. 1-2, S. 621-624
Lorentz force velocimetry for poorly conducting fluids - development and validation of a novel flow rate measurement device. - In: Journal of iron and steel research international, ISSN 1006-706X, Bd. 19.2012, Suppl. 1-2, S. 613-616
Flowrate measurement in turbulent liquid metal channel flow using time-of-flight Lorentz force velocimetry: experimental investigations and numerical modeling. - In: Journal of iron and steel research international, ISSN 1006-706X, Bd. 19.2012, Suppl. 1-1, S. 582-585
Lorentz force velocimetry for local velocity measurement. - In: Journal of iron and steel research international, ISSN 1006-706X, Bd. 19.2012, Suppl. 1-1, S. 578-581
Development of a non-contact electromagnetic surface velocity sensor for molten metal flow. - In: Journal of iron and steel research international, ISSN 1006-706X, Bd. 19.2012, Suppl. 1-1, S. 509-513