Magnetic Levitation Research Articles

Base pressure fluctuations on levitated freestream-aligned circular cylinder

Base pressure fluctuations associated with the large-scale wake structures behind a freestream-aligned circular cylinder and aerodynamic force fluctuations related to them are experimentally investigated in the wind tunnel tests. Measurements at ReD=6.97×104 and 1.04×105 were conducted using pressure-sensitive paint (PSP) and a magnetic suspension and balance system (MSBS) for creating a supportless condition. The obtained pressure fields were mainly analyzed by a modal decomposition combining azimuthal Fourier decomposition and proper orthogonal decomposition (POD). The pressure fluctuations caused by large-scale vortex shedding were observed from the results of frequency analysis for mode coefficients. The states of the fluctuations were classified into three patterns, which are anticlockwise/clockwise circular and flapping patterns. These patterns have been observed in the previous studies for velocity fluctuations in the wake of a freestream-aligned circular cylinder. The conditional sampling analysis revealed that the trend in the amplitude of the pressure fluctuations is different by the state, and the flapping pattern causes a large pressure difference across the cylinder axis. Furthermore, the relationship between the antisymmetric pressure fluctuations and lift fluctuations, which act in the lateral direction of the cylinder, is confirmed.

Investigation of a Wind Tunnel System for Spinning Body Using Magnetic Suspension

Investigation of a Wind Tunnel System for Spinning Body Using Magnetic Suspension

Research on 1/6 g Environment Simulation System Based on Magnetic Levitation Suspension

Research on 1/6 g Environment Simulation System Based on Magnetic Levitation Suspension

Helium damping characteristics of rotating superconducting rotor

The superconducting rotor magnetic levitation device can be used to make an angular velocity sensor, and the high-speed rotating superconducting rotor is the basis for achieving high-precision measurement of the superconducting rotor magnetic levitation device. The heat loss and radial mass eccentricity of the superconducting rotor can cause thermal quenching and resonance in the driving process, which is unfavorable to the driving process of the superconducting rotor. Therefore, it is necessary to maintain a certain quantity of helium gas in the superconducting cavity in the driving process, to transfer the heat generated by the driving process and avoid its resonance. But helium gas also has a drag torque on the rotating superconducting rotor, affecting the driving process of the superconducting rotor. Based on this, the drag torque of the helium on the rotating superconducting rotor is studied. Firstly, the Van der Waals equation is introduced to analyze the properties of low-temperature helium, and a method of studying the drag effect of low-temperature helium on the rotating superconducting rotor is proposed based on Reynolds law and Stoke’s first problem. Then, an experiment on superconducting rotor speed attenuation is conducted to verify the proposed analysis method. Based on the finite element method, the driving electromagnetic structure and driving torque of the superconducting rotor are analyzed. Finally, the influence of helium on the driving process of the superconducting rotor is investigated, including critical driving speed, acceleration time of the superconducting rotor, and frictional heat of the helium on the superconducting rotor. The research results further enrich the study of the drag torque of low-temperature gases on rotating superconductors, providing a reference for further optimizing the driving process of superconducting rotors.

A study on attraction type electromagnetic levitation systems for four different shaped objects

A study on attraction type electromagnetic levitation systems for four different shaped objects

A study on attraction type electromagnetic levitation systems for four different shaped objects

A study on attraction type electromagnetic levitation systems for four different shaped objects

A Mutually Coupled Stabilization Coil Configuration for Electromagnetic Levitation Melting With Frequency Consideration

A Mutually Coupled Stabilization Coil Configuration for Electromagnetic Levitation Melting With Frequency Consideration

Electromagnetic Field Calculation of Superconducting Magnetic Levitation Rotor under Alternating Magnetic Field

Electromagnetic Field Calculation of Superconducting Magnetic Levitation Rotor under Alternating Magnetic Field

Magnetic Levitation Control of Doubly-Fed Linear Motor with Multi-Phase AC Excited Mover

Magnetic Levitation Control of Doubly-Fed Linear Motor with Multi-Phase AC Excited Mover

Radial Basis Function-based Adaptive Gain Super-Twisting Controller for Magnetic Levitation System with Time-Varying External Disturbance

Radial Basis Function-based Adaptive Gain Super-Twisting Controller for Magnetic Levitation System with Time-Varying External Disturbance

Adjacent Cross-coupling Control for Magnetic Levitation System with Ultra-local Sliding Mode Algorithm

Adjacent Cross-coupling Control for Magnetic Levitation System with Ultra-local Sliding Mode Algorithm

Vibration Suppression of Superconducting Magnetic Levitation System by LCR Parallel Electromagnetic Shunt Damper

Vibration Suppression of Superconducting Magnetic Levitation System by LCR Parallel Electromagnetic Shunt Damper

Investigation of Critical Speed Increase by Five Degrees of Freedom Magnetic Levitation System with Combined Radial-Axial Magnetic Bearing

Investigation of Critical Speed Increase by Five Degrees of Freedom Magnetic Levitation System with Combined Radial-Axial Magnetic Bearing

Position Precision Control of Magnetic Levitation Systems Based on Generalized Multiple Disturbances Estimation and Compensation

Position Precision Control of Magnetic Levitation Systems Based on Generalized Multiple Disturbances Estimation and Compensation

Curved Magnetic Levitation Conveying System for Thin Steel Plates with Magnetic Field Applied from Edge Direction

Curved Magnetic Levitation Conveying System for Thin Steel Plates with Magnetic Field Applied from Edge Direction

Research on the Axial Stability of Large-Capacity Magnetic Levitation Flywheel Driven by Axial-Flux Permanent Magnet Machine Based on Runge-Kutta Method

Research on the Axial Stability of Large-Capacity Magnetic Levitation Flywheel Driven by Axial-Flux Permanent Magnet Machine Based on Runge-Kutta Method

Thermal effects associated with the crack of high-temperature superconducting magnetic levitation system

Based on the magnetic flux pinning characteristics of the non-ideal type II superconductor YBa2Cu3O7−x, the high-temperature superconducting magnetic levitation system has the advantages of self-stability in levitation and low energy consumption. Thermal stress, electromagnetic force, and other mechanical stress may cause the micro-cracks to expand and eventually lead to fractures in the application of superconducting materials, significantly affecting the superconductor’s ability to transmit current. The superconducting magnetic levitation system with low damping is prone to nonlinear vibration of large amplitude under external interference, which affects the system’s regular operation. Due to the limitations of experimental conditions, it is difficult to analyze complex physical phenomena with cracks and obtain the distribution characteristics of electromagnetic, heat, and force inside the superconductor in the nonlinear vibration process, as theoretical modeling can compensate for this deficiency. In this paper, we study the fracture behavior of the YBa2Cu3O7−x bulk superconductor under nonlinear vibration based on the flux creep and flow models. The temperature of the superconductor in the nonlinear vibration of the superconducting levitation system is calculated with center cracks. The flux flow phenomenon in the bulk superconductor for various cracks under the bifurcation vibration is presented. The results show that the temperature of the superconductor will dramatically rise in nonlinear vibration under thermal insulation conditions, and the distribution position is affected by the cracks. For the 15 and 12 mm center cracks, a large amount of heat is generated around the crack and causes the temperature to rise above the critical temperature.

Development of Noncontact Active Magnetic Levitation System Without Magnetic Guidance on Guideway

Development of Noncontact Active Magnetic Levitation System Without Magnetic Guidance on Guideway

A Novel Triple-actuator Magnetic Suspension Balance System with Enhanced Load and Stability

A Novel Triple-actuator Magnetic Suspension Balance System with Enhanced Load and Stability

Non-contact Gripping of Thin Steel Plates by Electro Magnetic Suspension

Non-contact Gripping of Thin Steel Plates by Electro Magnetic Suspension