Magnetically Induced Stress Waves in a Conducting Solid—Theory and Experiment

1974 ◽  
Vol 41 (3) ◽  
pp. 641-646 ◽  
Author(s):  
F. C. Moon ◽  
S. Chattopadhyay
Keyword(s):  
Magnetic Field ◽  
Half Space ◽  
Body Force ◽  
Capacitor Bank ◽  
Thermoelastic Stress ◽  
Compressional Wave ◽  
Stress Waves ◽  
Stress Fields ◽  
Radial Magnetic Field ◽  
Transient Magnetic Fields

The induction of stress waves by transient magnetic fields has been examined analytically for a conducting half space and experimentally for a cylindrical rod. The analytical model predicts both a body force generated compressional wave and a thermoelastic stress wave. The model shows the magnetic, temperature, and stress fields in the half space for various times after a prescribed magnetic field is applied at the boundary. In the experiment a transient, radial, magnetic field (up to 15 kilogauss) was applied to the end of a copper bar. The field was generated by discharging a small capacitor bank through a flat helical coil. The measured compressional stresses obtained in this manner were of the order of the measured magnetic pressure (B2/2μ0), at the end of the bar.

Analysis of Cogging Torque of PM Motor with Radial Magnetic Field and Parallel Magnetic Field

2011 ◽  
Vol 105-107 ◽  
pp. 2289-2294
Author(s):  
Jun Qiang Lian ◽  
Shun Yi Xie ◽  
Jian Wang
Keyword(s):  
Magnetic Field ◽  
Air Gap ◽  
Analytic Method ◽  
Analytic Model ◽  
Parallel Magnetic Field ◽  
Radial Magnetic Field ◽  
Fem Model ◽  
Cogging Torque ◽  
Fem Method

This paper provide two methods to analyze the cogging torque of PM motor with radial magnetic field and parallel magnetic field, FEM method and Analytic method. The FEM model and Analytic model of PM motor with radial magnetic field and parallel magnetic field are founded. We analyze the model in both methods. From the result of analysis. The air-gap magnetic density of PM motor can be analyzed. We can find the cogging torque of radial magnetic field PM motor is much heavily than the cogging torque of parallel magnetic field PM motor. The result of Analytic method is close to the result of FEM method. The Analytic method is useful in analyze the cogging torque of PM motor.

Magnetohydrodynamic lubrication flow between parallel rotating disks

1962 ◽  
Vol 13 (1) ◽  
pp. 21-32 ◽  
Author(s):  
W. F. Hughes ◽  
R. A. Elco
Keyword(s):  
Magnetic Field ◽  
Axial Magnetic Field ◽  
Load Capacity ◽  
Electrical Energy ◽  
Axial Current ◽  
Frictional Torque ◽  
Rotating Disks ◽  
Radial Magnetic Field ◽  
Electrically Conducting ◽  
Parallel Disks

The motion of an electrically conducting, incompressible, viscous fluid in the presence of a magnetic field is analyzed for flow between two parallel disks, one of which rotates at a constant angular velocity. The specific application to liquid metal lubrication in thrust bearings is considered. The two field configurations discussed are: an axial magnetic field with a radial current and a radial magnetic field with an axial current. It is shown that the load capacity of the bearing is dependent on the MHD interactions in the fluid and that the frictional torque on the rotor can be made zero for both field configurations by supplying electrical energy through the electrodes to the fluid.

NUMERICAL SIMULATION OF MARANGONI MAGNETOHYDRODYNAMIC BIO-NANOFLUID CONVECTION FROM A NON-ISOTHERMAL SURFACE WITH MAGNETIC INDUCTION EFFECTS: A BIO-NANOMATERIAL MANUFACTURING TRANSPORT MODEL

2014 ◽  
Vol 14 (03) ◽  
pp. 1450039 ◽  
Author(s):  
O. ANWAR BÉG ◽  
M. FERDOWS ◽  
S. SHAMIMA ◽  
M. NAZRUL ISLAM
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Prandtl Number ◽  
Stream Function ◽  
Magnetic Induction ◽  
Body Force ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Convection Boundary Layer ◽  
Force Parameter

Laminar magnetohydrodynamic Marangoni-forced convection boundary layer flow of a water-based biopolymer nanofluid containing nanoparticles from a non-isothermal plate is studied. Magnetic induction effects are incorporated. A variety of nanoparticles are studied, specifically, silver, copper, aluminium oxide and titanium oxide. The Tiwari–Das model is utilized for simulating nanofluid effects. The normalized ordinary differential boundary layer equations (mass, magnetic field continuity, momentum, induced magnetic field and energy conservation) are solved subject to appropriate boundary conditions using Maple shooting quadrature. The influence of Prandtl number (Pr), magnetohydrodynamic body force parameter (β), reciprocal of magnetic Prandtl number (α) and nanofluid solid volume fraction (φ) on velocity, temperature and magnetic stream function distributions is investigated in the presence of strong Marangoni effects (ξ i.e., Marangoni parameter is set as unity). Magnetic stream function is accentuated with body force parameter. The flow is considerably decelerated as is magnetic stream function gradient, with increasing nanofluid solid volume fraction, whereas temperatures are significantly enhanced. Interesting features in the flow regime are explored. The study finds applications in the fabrication of complex biomedical nanofluids, biopolymers, etc.

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