Numerical Simulation and Optimization Design for Magnetic Fluid Sealing Device
In this paper the principle of magnetic fluid seals is discussed. Based on the finite element software ANSYS, the magnetic field of magnetic fluid sealing device with three slots and four pole teeth is analyzed, and the size parameters of magnetic fluid sealing pole are optimized. The results show that the difference between the maximum and minimum intensity of magnetic field in the area near the shaft determine the sealing capacity of sealing device. The gap of seal should not be larger than 0.3mm. The optimized parameters which are provided for practical design can increase sealing capacity of sealing device as well as decrease the volume of sealing device.
Magnetic‐field analysis of ferrofluidic seals for optimum design
Ferrofluidic devices have found applications in laser systems, high‐vacuum equipment, computers, loudspeakers, inertia dampers, and motors. With the technique of magnetic‐fluid sealing, one is called upon to produce custom solutions for complex and diverse seal problems, many of which may be characterized by very hostile environments, wide temperature ranges, and intense radioactive conditions. In designing a magnetic circuit for a magnetic‐liquid seal, a number of factors, such as the size of the available envelope, pressure differential across the seal, chemical compatibility with various environments, and proper selection of permanent and soft magnetic materials need to be considered for achieving the most cost‐effective solution while meeting the entire range of requirements for any specific application. In order to evaluate flux leakage and fringing while accounting for nonlinear characteristics of magnetic materials, it becomes necessary to resort to numerical techniques to determine the effect caus...
Shape and surface texture of molten droplets deposited on cold surfaces
When a molten droplet impacts on a cold surface, the interaction between solidification and fluid dynamics can lead to different shapes and surface textures of deposited droplets. This article presents an experimental study on deposition of small droplets (39 μm diameter) of molten wax ink on solid surfaces. Our results show that both the final shape and the surface texture of deposited droplets are extremely sensitive to deposition conditions, which include initial temperature of droplets, type of substrate surface and distance between substrate and printhead. Different surface textures are observed and shown to depend on the thermal and flow histories of ink droplets during the process of impact. A test using crystalline wax reveals crystallization as one of the major factors in determining the final texture.