scholarly journals Magneto-Elastic μ-Vibrator for Smashing Thrombus

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 74
Author(s):  
Wei Li ◽  
Cong Xue ◽  
Xinxin Li
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Flow Rate ◽  
Rate Ratio ◽  
Detection Method ◽  
Resonant Mode ◽  
Flow Rate Ratio ◽  
Element Simulation ◽  
Ratio Detection

A miniaturized thrombus dredger is proposed and developed in this study. The flexural resonance of the µ-resonator dredger is driven by a bulk-extensional magneto-elastic vibrator that is externally excited by alternating magnetic-field. With the fabricated prototype of the resonant dredger, a mice thrombus blocked in a simulated vessel is broken into micro-pieces, and the previously blocked vessel can recover to an unobstructed state within 1 h. A flow-rate ratio detection method is used to evaluate the thrombus-cleaning effectiveness. The comparison between the finite-element simulation and the experimental results validates the flow-rate ratio detection method. By optimally exciting the resonant dredger in its third resonant mode, the flow-rate ratio in the cleaned vessel increases by about 2.7 times compared with that in the partly blocked vessel, and the thrombus is smashed into micro-pieces.

Simulation research on low frequency sound absorption of monostable metamaterials

2021 ◽  
Vol 263 (6) ◽  
pp. 648-652
Author(s):  
Tuo Xing ◽  
Xianhui Li ◽  
Xiaoling Gai ◽  
Zenong Cai ◽  
Xiwen Guan
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Theoretical Model ◽  
Finite Element Simulation ◽  
Sound Absorption ◽  
Magnetic Force ◽  
Low Frequency ◽  
Low Frequencies ◽  
Element Simulation ◽  
Simulation Results

The monostable acoustic metamaterial is realized by placing a flexible panel with a magnetic proof mass in a symmetric magnetic field. The theoretical model of monostable metamaterials has been proposed. The method of finite element simulation is used to verify the theoretical model. The magnetic force of the symmetrical magnetic field is simplified as the relationship between force and displacement, acting on the mass. The simulation results show that as the external magnetic force increases, the peak sound absorption shifts to low frequencies. The theoretical and finite element simulation results are in good agreement.

Finite Element Simulation of Seven-Hole Propellant Extrusion and the Optimization of Die Compression Ratio

2014 ◽  
Vol 941-944 ◽  
pp. 2373-2377 ◽  
Author(s):  
Dan Dan Ji ◽  
Xin Liao
Keyword(s):  
Finite Element ◽  
Velocity Distribution ◽  
Internal Pressure ◽  
Finite Element Simulation ◽  
Flow Rate ◽  
Compression Ratio ◽  
Velocity Fields ◽  
Flow Channel ◽  
Flow Temperature ◽  
Element Simulation

FLUENT was used to simulate the propellant flow law in the flow channel of a seven-hole propellant die, and distributions of internal pressure, velocity fields was obtained. The influence of compression ratio, temperature and flow rate was analyzed. The results show that compression ratio influences the pressure and velocity distribution obviously. In addition, flow temperature and inlet rate have a small effect on pressure and velocity distribution.

Study of the effect of the demagnetizing field in Epstein strips of grain-oriented electrical steels through 3D finite element analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Leysmir Adriana Millan Mirabal ◽  
Oualid Messal ◽  
Abdelkader Benabou ◽  
Yvonnick Le Menach ◽  
Loic Chevallier ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Three Dimensional ◽  
Element Analysis ◽  
Electrical Steels ◽  
3D Finite Element ◽  
Content Type ◽  
Demagnetizing Field ◽  
Element Simulation

Purpose The purpose of this study is to explore the effect of the demagnetizing field in the Epstein characterization of grain-oriented electrical steels through a finite element method (FEM) simulations. Design/methodology/approach A 3D finite element simulation has been realized to represent the parallel and X-stacking configurations in the Epstein frame. The numerical results have been compared with experimental measures. Findings In a parallel configuration, the measured induction is actually the one in the material, whereas the resulting magnetic field differs from the applied one (in magnitude and angle) due to the shape anisotropy (demagnetizing field). In X-stacking configuration, the resulting magnetic field is close to the applied magnetic field (and then the supposed excitation field in the Epstein frame), whereas the magnetic induction has deviated from the axis of the strips. Originality/value Both stacking configurations (parallel and cross) of the Epstein frame are analyzed by three-dimensional finite element simulation.

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