Analytical and Numerical Approaches to Predict the Flow Characteristics of a Magnetorheological Fluid in Rotational Symmetric Cross Sections

2012 ◽  
Vol 504-506 ◽  
pp. 399-404
Author(s):  
Sebastian Rösel ◽  
Marion Merklein ◽  
Martin Grüner
Keyword(s):  
Numerical Simulation ◽  
Magnetic Flux ◽  
Flux Density ◽  
Cross Sections ◽  
Flow Characteristics ◽  
Magnetic Flux Density ◽  
Flux Lines ◽  
Hydroforming Process ◽  
Fluid Behaviour ◽  
Numerical Approaches

For a better understanding of the hydroforming process using magnetorheological fluids as a medium it is necessary to gain basic information for an analytical and numerical description of the fluid behaviour under process relevant conditions. Therefore an experimental setup is build up, which consists of a pressure chamber and a rotational symmetric outlet. Different parameters like feed rate and magnetic flux density are varied. Afterwards an analytical approach and a numerical model are developed. To get the relevant material input data for the fluid description an additional numerical simulation of the created magnetic flux density with flux lines perpendicular to the symmetry line of the outlet is performed. The leakage rates, which are observed for the experiments, are compared to the analytically calculated ones and to the results of the numerical simulation.

scholarly journals STUDY OF ACOUSTIC SOURCE EXCITED BY PULSED MAGNETIC FIELD

2021 ◽  
pp. 2140008
Author(s):  
YANJU YANG ◽  
CHUNLEI CHENG ◽  
WENYAO YANG ◽  
JIE LI ◽  
ZHENGFU CHENG ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Analytical Solution ◽  
Magnetic Flux ◽  
Flux Density ◽  
Magnetic Induction ◽  
Pulsed Magnetic Field ◽  
Magnetic Flux Density ◽  
Acoustic Source ◽  
Thermoacoustic Imaging

In magnetoacoustic tomography with magnetic induction and magnetically mediated thermoacoustic imaging, tissues are exposed to an alternating field, generating magnetoacoustic and thermoacoustic effects in the tissues. This study aimed to investigate the relationship between magnetoacoustic and thermoacoustic effects in a low-conductivity object put in a Gauss-pulsed alternating magnetic field. First, the derivations of the magnetic flux density and electric field strength induced by a Gauss-pulsed current flowing through the coil based on the theory of electromagnetic field were examined. Second, the analytical solution of the magnetic field was studied by simulation. To validate the accuracy of the analytical solution, the analytical solution and the numerical simulation of the magnetic flux density were compared. It shows that the analytical solution coincides with the numerical simulation well. Then, based on the theoretical analysis of the acoustic source generation, numerical studies were conducted to simulate pressures excited by magnetoacoustic and thermoacoustic effects in low-conductivity objects similar to tissues in the Gauss-pulsed magnetic field. The thermoacoustic effect played a leading role in low-conductivity objects placed in the Gauss-pulsed magnetic field, and the magnetoacoustic effect could be ignored. This study provided the theoretical basis for further research on magnetoacoustic tomography with magnetic induction and magnetically mediated thermoacoustic imaging for pathological tissues.

scholarly journals Analysis and Simulation on the Effect of Rotor Interturn Short Circuit on Magnetic Flux Density of Turbo–Generator

2016 ◽  
Vol 67 (5) ◽  
pp. 323-333 ◽  
Author(s):  
Yu-Ling He ◽  
Meng-Qiang Ke ◽  
Gui-Ji Tang ◽  
Hong-Chun Jiang ◽  
Xing-Hua Yuan
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Short Circuit ◽  
Digital Simulation ◽  
Magnetic Flux Density ◽  
Harmonic Amplitude ◽  
General Magnetic Field ◽  
Flux Lines ◽  
Turbo Generator

Abstract The intent of this paper is to investigate the effect of the interturn short circuit fault (ISCF) in rotor on the magnetic flux density (MFD) of turbo-generator. Different from other studies, this work not only pays attention to the influence of the faulty degrees on the general magnetic field, but also investigates the effect of the short circuit positions on the harmonic components of MFD. The theoretical analysis and the digital simulation through the FEM software Ansoft are performed for a QSFN-600-2YHG turbo-generator. Several significant formulas and conclusions drawn from the analysis and the simulation results are obtained to indicate the relation between the harmonic amplitude of the MFD and the faulty degree (via nm, the number of the short circuit turns), and the relation between the MFD harmonic amplitude and the faulty position (via αr, the angle of the two slots in which the interturn short circuit occurs). Also, the developing tendency of the general magnetic field intensity, the distribution of the magnetic flux lines, and the peak-to-peak value of MFD are presented.

Numerical Simulation of High Frequency Electromagnetic Field in Soft Contact Continuous Casting Mold

2012 ◽  
Vol 482-484 ◽  
pp. 1534-1537
Author(s):  
Peng Tian ◽  
Xing Juan Wang ◽  
Li Guang Zhu ◽  
Yue Kai Xue ◽  
Wei Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Electromagnetic Field ◽  
Magnetic Flux ◽  
Continuous Casting ◽  
Flux Density ◽  
Three Dimensional ◽  
Current Strength ◽  
Magnetic Flux Density ◽  
Continuous Casting Mold ◽  
Power Frequency

Based on electromagnetic theory, a billet model electromagnetic continuous casting of physical and mathematical were established. The three-dimensional mold for billet electromagnetic field was calculated by finite element method of ANSYS three-dimensional numerical simulation. Then the distribution of the electromagnetic field inside the crystal was gotten. At the same time, the influence of the power frequency and current strength on the intensity and distribution of the magnetic field were simulated. The result shows that the maximum of the electromagnetic flux density lies in the center of induction coil (steel surface in the center of the coil), and the magnetic flux density gradually reduces along the casting direction; the magnetic flux density increases while the power frequency is increasing; the magnetic flux density increases with the increasing of the current intensity.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

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