Investigating the Magnetic Characteristics of 12/8 Switched Reluctance Motor for Enhanced Starting Torque

The switched reluctance motor (SRM) is among the special purpose electric machine family. It is simple in construction and avoids use of magnet so it is cheap to manufacture. The magnetic characteristics and simulation of three phase 12/8 switched reluctance motor (SRM) for enhanced starting torque is presented. The motor was analyzed using finite element technique (FET) and it was improved by focusing on the impact of important geometrical parameters on torque and efficiency. From the simulated results, the motor attained maximum efficiency of 91.7% at a speed of 1648.6 rpm and recorded a maximum torque of 321.1 Nm at a speed of 34.4 rpm. The magnetic flux lines and densities were also recorded. The maximum and minimum magnetic flux lines of the motor as observed were 1.2x10-3 Wb/m and -8.5x10-4 Wb/m respectively while the respective values of the maximum and minimum magnetic flux density of the motor were 3.8x10-1 T and 2.11x10-9 T. The results show that most of the field energy is confined within the motor and also concentrated in the air gap region of the motor. Dynamic analysis of the motor was performed for 0.02 s at a damping coefficient of 0.71 μNms/rad. The results showed that the motor has lower torque ripple. The preference to use this type of motor where high speed operation and better starting torque are needed has been highlighted in this study. Keywords: Switched reluctance motor, static characteristics, transient analysis, torque, magnetic flux

State-of-the-Art and Advancement Paths for Inductive Pulsed Plasma Thrusters

An inductive pulsed plasma thruster (IPPT) operates by pulsing high current through an inductor, typically a coil of some type, producing an electromagnetic field that drives current in a plasma, accelerating it to high speed. The IPPT is electrodeless, with no direct electrical connection between the externally applied pulsed high-current circuit and the current conducted in the plasma. Several different configurations were proposed and tested, including those that produce a plasma consisting of an accelerating current sheet and those that use closed magnetic flux lines to help confine the plasma during acceleration. Specific impulses up to 7000 s and thrust efficiencies over 50% have been measured. The present state-of-the-art for IPPTs is reviewed, focusing on the operation, modeling techniques, and major subsystems found in various configurations. Following that review is documentation of IPPT technology advancement paths that were proposed or considered.

Therapy of traumatic injuries of the spinal cord by magnetic nanoparticles: experimental aspects of promising technology

In this analytical review an attempt to sum up the available data in magnetite nanoparticle-marked stem cells utilization is made. Now this question remains on the experimental study level. Available data is diversified and needs an integral look to be taken. It is found that magnetite nanoparticles are non-toxic for the cells and do not interrupt physiological metabolic pathways. They can also be captured by cell using different transporters. Cells containing the magnetite nanoparticles can migrate along the magnetic flux lines. Animals with traumatic spinal cord lesions that got the nanoparticles-containing cell therapy showed the neurological status improvement. There is very little data in usage of this method in clinical practice; the solution of this problem requires more clinical trials.

Effect of Aerosil and Oleic Acid on Sedimentation of Magnetorheological Fluid

Magnetorheological Fluids (MRFs) are considered as smart fluids because they control viscosity using external magnetic field. It contains ferro-magnetic powder which are aligned in magnetic flux lines. The magnetic force between particles are controlled by magnetic field intensity. This controllable viscosity makes them acceptable in many mechanical applications, but due to difference in density between suspended particles and carrier fluid sedimentation is bound to occur. This thus creates the need of some additives. In our study, silica Nano particles (commercially known as Aerosil 200) is used as stabilizer and Oleic Acid is used as surfactant and their effect on sedimentation is studied in this article. Some other synthesis parameters like particle concentration, stirring duration and material loading also cause some change in sedimentation rate.

The Optimal Design and Simulation Analysis of High-Speed Switching Valve Based on Magnetorheological Fluid

This article designed a kind of magnetorheological high-speed on-off valves and made optimized design based on the nature of the magnetorheological fluid(MRF). ANSYS software was used to analyze magnetic field of the two different structures and get the magnetic flux lines distribution and flux density map. The simulation analysis results show that: optimized high speed switching valve, can reduce the loss of the coil and the rise of temperature, improves the life of the valve body, it also can shorten the switching response time and improves the reliability of the valve.