Equilibrium configurations in a magnetic fluid-based field mapping and gas pressure measuring system: Experiment and simulations

Abstract

In this work, we present a measurement system based on the thin layer of magnetic fluid aimed at scanning either the non-uniform magnetic field distribution applicable for magnetic levitation systems (MagLev) or determining small excess gas pressure. The key idea is based on the photo registration of a transparent air-filled cavity formed in a thin magnetic fluid layer due to balancing the gas pressure and the pressure emerging due to magnetic forces. As a result, the contour of the magnetic field lines in 3D space is visible. It is shown that the theoretical analysis and numerical simulations are consistent with experimental results.

Mittag–Leffler Function as an Approximant to the Concentrated Ferrofluid’s Magnetization Curve

“…Thus, it can be easily used in applied problems, which demand the phenomenological high-accurate analytic representation of ferrofluid's magnetization when the controlling configuration of the external magnetic field is stated by the system's construction. Among such applications, one can mention different microfluidic devices operating with microparticles and biological cells, e.g., [12,35], devices based on the magneto-Archimedes effect, e.g., [15,16,23], ferrofluid-based measuring devices [19,36], etc.…”

“…This situation induces the emergence of several alternative approaches aimed at an efficient fitting of ferrofluid's magnetisation stated as an explicit function of the external magnetic field by an appropriate set of approximating functions [16][17][18][19] adjusted to experimental conditions.…”

Magnetic Fluids: The Interaction between the Microstructure, Macroscopic Properties, and Dynamics under Different Combinations of External Influences

“…Therefore, it is necessary to obtain the spatial distribution of the magnetic field for such MagLev systems. In principle, the corresponding calculations do not require complex techniques [ 280 ]. Calculations can be performed using various standard scientific programs, representing a generally accepted approach.…”

“…These finite-size effects prevent measurements in miniature magnetic levitation systems [ 278 ]. A new method for scanning the topology of the magnetic field, as proposed in [ 280 , 281 ], aims for a more accurate assessment of the size of the magnetic field region for magneto-fluidic systems with different parameters, predicting the behavior of non-magnetic inclusions in such systems under the influence of inhomogeneous magnetic fields.…”

Влияние Воздушного Пузыря На Ориентацию Жидкого Кристалла

“…Для объяснения наблюдаемого эффекта оценим влияние пузыря на поверхностный слой ЖК. При натирании под типичным давлением 100 Па [7] поверхности ячейки размером 10 мм10 мм (10 -4 м 2 ) сила, действующая на поверхность, составляет 10 -2 Н, т. е. на площади 22 мм 2 она равна 410 -4 Н. При поверхностном натяжении 0.610 -1 Дж/м² = 0.610 -1 Н/м и размере пузыря 2 мм стенка пузыря действует на поверхность ориентирующего покрытия со слоем ЖК с силой 1.210 -4 Н. Эти значения находятся в соответствии со значениями давления газа в пузырях различных жидкостей [8].…”