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Tuesday, August 24, 2021 | History

3 edition of Final report on numerical study of magnetic damping during unidirectional solidification (NASA grant #: NCC3-435), duration: October 1, 1995 - September 30, 1997 found in the catalog.

Final report on numerical study of magnetic damping during unidirectional solidification (NASA grant #: NCC3-435), duration: October 1, 1995 - September 30, 1997

Ben Q. Li

Final report on numerical study of magnetic damping during unidirectional solidification (NASA grant #: NCC3-435), duration: October 1, 1995 - September 30, 1997

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  • 8 Currently reading

Published by National Aeronautics and Space Administration, National Technical Information Service, distributor in [Washington, DC, Springfield, Va .
Written in English

    Subjects:
  • Three dimensional models.,
  • Fluid flow.,
  • Magnetic effects.,
  • Electromagnetic fields.,
  • Finite element method.,
  • Computer programs.,
  • Magnetic fields.,
  • Heat transfer.

  • Edition Notes

    Other titlesNumerical study of magnetic damping during unidirectional solidification (NASA grant #: NCC3-435), duration: October 1, 1995 - September 30, 1997.
    Statementsubmitted by: principal investigator, Ben Q. Li.
    Series[NASA contractor report] -- 206053., NASA contractor report -- NASA CR-206053.
    ContributionsUnited States. National Aeronautics and Space Administration.
    The Physical Object
    FormatMicroform
    Pagination1 v.
    ID Numbers
    Open LibraryOL15491584M

    Magnetic damping definition is - mechanical damping produced by the reaction of a magnetic field with eddy currents due to relative motion of conductor and field. in the magnetic field generates a voltage in the cup. • A current is generated in the cup’s circular path. • A current-carrying conductor in a magnetic field experiences a force proportional to the current. • The result is a force proportional to and opposing the velocity. • The dissipated energy shows up as I2R heating of the cup.


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Final report on numerical study of magnetic damping during unidirectional solidification (NASA grant #: NCC3-435), duration: October 1, 1995 - September 30, 1997 by Ben Q. Li Download PDF EPUB FB2

FINAL REPORT ON _i i t. c WT"--NUMERICAL STUDY OF MAGNETIC DAMPING DURING UNIDIRECTIONAL SOLIDIFICATION (NASA GRANT : NCC) Duration: October 1, - Septem Submitted to: H.

de Groh III Processing Sciences and Technology Branch NASA Lewis Research Center, M. Cleveland, Final report on numerical study of magnetic damping during unidirectional solidification book Submitted by: Principal. NASA contractor report, NASA CR Other Titles: Numerical study of magnetic damping during unidirectional solidification (NASA grant : NCC), duration: October 1, - Septem Responsibility: submitted by principal investigator, Ben Q.

With the model so tested, various numerical simulations are carried out for the Sn Pb melt convection and temperature distribution in a cylindrical cavity with and without the presence of a transverse magnetic field. Numerical results show that magnetic damping can be effectively applied to reduce turbulence and flow levels in the melt undergoing solidification and over a certain threshold value a higher magnetic field resulted in Author: Ben Q.

In this study, we paid attention to the fact that liquid oxygen, which is one of the propellants widely used in rockets, is a paramagnetic substance. We numerically investigated the damping effect of the magnetic eld when liquid oxygen sloshing in a tank occurred.

Numerical Cited by: 4. Nowadays, the use of baffle plates is anticipated to be one of potential devices used to dampen the sloshing of propellant in rocket tanks. However, some of previous studies reported that the use of a baffle plate may cause larger pressure fluctuations in the tank.

In this study, aiming at damping the sloshing without a baffle plate, we paid attention to the characteristic that liquid oxygen Cited by: 4.

Thus g-fitter can cause the formation of compositional fluctuations (striations). The efficiency of its damping by static magnetic fields is, therefore, of practical importance for crystal growth and solidification experiments under microgravity.

Numerical model The numerical model has been presented in detail before [4]. adshelp[at] The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A.

THE MODEL Electromagnetic induction is important in part because it A. Magnetic friction force bridges the areas of electricity and magnetism. 1 Many Magnetic damping of the motion of a conductor as it researchers have discussed students conceptual difficulties enters or exits a region of magnetic field can be explained by in understanding.

Magnetic damping is one of the important parameters to control the response and stability of maglev systems. An experimental study is presented to measure the magnetic damping using a direct method. Then, the magnetic saturation phenomenon of the magnetorheological damper is simulated using the finite element method, and the numerical simulation results are compared with the experimental results.

Notice finally that in the case of the magnetic surface of topological insulators, the magnetic damping is directly proportional to the conductivity tensor. Indeed, since ˆ v p (z × σ ˆ), v ˆ p ˆ v (z × σ ˆ), establishing a direct equivalence between spin dynamics (spinspin correlation) and charge dynamics (current-current correlation).

Magnetic damping is one of the important parameters that control the response and stability of maglev systems. An experimental study to measure magnetic damping directly is presented. A plate attached to a permanent magnet levitated on a rotating drum was tested to investigate the effect of various parameters, such as conductivity, gap, excitation frequency, and oscillation amplitude, on magnetic damping.

Damping: Landau-Lifshitz vs Gilbert 4 Since the second result is in agreement with the fact that a very large damping should produce a very slow motion while the rst is not, one may conclude that the Landau-Lifshitz-Gilbert equation is more appropriate to describe magnetization dynamics.

Landau-Lifshitz vs. performance of designed machines, their applications during the design procedure are limited mostly to the final validation stage. This is because numerical techniques are time-consuming, hardly provide facilities to systematically change the topology of the under study device and.

A preliminary study was conducted to investigate numerical models that can be used to simulate the dynamic behaviour of a damper based on magnetorheological (MR) materials.

Several articles presenting the results of experimental testing and mathematical modelling. The numerical results show that the magnetic damping suppressed the nonlinear evolution of r-modes since the saturation amplitude is reduced to a great extent.

In particular, because of the presence of the generated toroidal magnetic field, the spin-down of the stars is terminated and the viscous heating effects are also weakened. While stirring is studied as an alternative to control melt turbulence, a more popular and well-established technology has been to apply a d.

magnetic field to damp out turbulence and flow irregularities to reduce the solutal striation and other defects in the final crystals. 8, The effect of the magnetic field on the improvement of single-crystal qualities grown from melt was first demonstrated in the s, 55 and magnetic damping.

As discussed in Motional Emf, motional emf is induced when a conductor moves in a magnetic field or when a magnetic field moves relative to a conductor. If motional emf can cause a current loop in the conductor, we refer to that current as an eddy current. Eddy currents can produce significant drag, called magnetic damping, on the motion involved.

Consider the apparatus shown in Figure 1, which swings. Study of Electromagnetic Damper Pranav Teli1, Vinayak Tamhankar2, Suyash Zagade3, Aniket Suvre4 1, 2 System Engineer, Tata Consultancy Services, 3 Maintenance Eng.

Chawgule Dockyard Pvt. Ltd. 4 Graduate Eng. Dexcel Plast Pvt. Ltd. Abstract - This paper discussing all the design for electromagnetic damping systems for passenger vehicle.

Electromag. A description of the theoretical basis of damping is presented from early developments to the latest discussions of damping in ferromagnetic thin-films and multilayers.

An overview of the time and frequency domain methods used to study precessional magnetisation behaviour and damping in thin-films and multilayers is also presented. The distribution of the magnetic flux density B is slightly different for different types of source boundary conditions.

In Fig. 5 is the MVP source description and Fig. 6 is the magnetic field strength H. Fig. 5 Distribution of the magnetic flux density for MVP magnetic field BC Fig. 6 Distribution of the magnetic. The study developed in this paper is concerned with dampers consisting of the following conductors and magnetic fluxes: (a) a rectangular conductor and an eccentric circular flux, (b) a circular conductor and an eccentric circular flux, and (c) polygonal conductors of various shapes and a concentric circular flux.

Summary This chapter contains sections titled: Introduction Eddy Currents Domain Wall Velocity Switching in Thin Films Time Effects Magnetic Damping Magnetic Resonance Problems.

Magnetic damping of the spin, the decay rate from the initial spin state to the final state, can be controlled by the spin transfer torque. Such an active control of damping has given birth to. formed under magnetic field. In this study, it is clearly showed that the clumping effect occur due to the rapid increments of both force and displacement transmission through the carrier fluid.

Therefore, the magneto-rheological fluids become stiffer and have higher damping values. [8] Figure 1 shows the.

This work aims to establish the mathematical model with the high effectiveness in predicting the damping force of an MR damper with nonmagnetized passages in piston. The pressure drops due to viscous loss, MR effect, and the minor losses at the inlet and outlet of passages are considered in the mathematical model.

The widely reported Bingham model is adopted to describe the mechanical property. is a platform for academics to share research papers.

Magnetic damping is a simple and ideal solution. With magnetic damping, drag is proportional to speed and becomes zero at zero velocity. Thus the oscillations are quickly damped, after which the damping force disappears, allowing the balance to be very sensitive. (See. ) In most balances, magnetic damping is accomplished with a conducting disc that rotates in a fixed field.

Testing theoretical models of magnetic damping using an air track Figure 1. (a) Experimental setup: a magnet is xed to a glider sliding on an air track.

(b) Cross section of the air track showing the reference system and the magnetic eld pattern. with the theoretical motion equations solved by applying the theoretical model.

Furthermore. The objective of this study is to develop a method of numerically analyzing rotary Magneto-Rheological (MR) fluid dampers, and using this method to analyze a MR fluid damper with non-linear damping surfaces. Such a damper could then be put in parallel with a compliant element and controlled properly to produce effective variable compliance.

The U. Department of Energy's Office of Scientific and Technical Information. magnetic induction dampers, study their possible integration in buildings, and scale them for use in dampening motion due to earthquakes or strong winds. Simulations will help us assess the applicability and the potential benefits of structural magnetic induction dampers.

Numerical study of magnetic circuit response in magneto-rheological damper Mohammad Sadak Ali Khan (Department of Mechanical Engineering, M.Hyderabad, India) A. Suresh (Sreyas Institute of Engineering and Technology, Hyderabad, INdia).

The dynamics and the damping of magnetization are of paramount importance to understand and predict the properties of magnetic materials used in a variety of applications. For example, spin-transfer torque magnetic random-access memory cells (STT-MRAM) are expected to switch fast, reliably, and with low power consumption, which requires low.

These models are analyzed to study the variation of magnetic field intensity and magnetic flux density with respect to the input current to the coil. Analysis is carried out using ANSYS R 11 software. The variation of 2D flux lines, magnetic flux density and magnetic field intensity for the different models at.

Eddy Currents and Magnetic Damping. As discussed in Motional Emf, motional emf is induced when a conductor moves in a magnetic field or when a magnetic field moves relative to a motional emf can cause a current loop in the conductor, we refer to that current as an eddy currents can produce significant drag, called magnetic damping, on the motion involved.

material during that cycle. This loss is made up in two components: (1) the hysteresis loss and (2) eddy current loss.

The hysteresis loss is the energy loss when the magnetic material is going through a cycling state. The eddy current loss is caused when the lines of. 4. MR dampers due to the apparent viscosity of magnetic fluids can operate in semi-active conditions.

Magneto-rheological Fluid Composition: Oil (having low permeability) with varying percentage of micron-sized (µ) iron particles coated with anti-coagulant material. Magnetic damping is of critical importance for devices that seek to exploit the electronic spin degree of freedom, as damping stronglya˙ects the energy required and speed at which a device can operate.

However, theory has struggled to quantitatively predict the damping, even in common ferro-magnetic materials13. This presents a challenge. In this paper we present an improved analytical and numerical method for calculation of magnetic field in tangential surface-mounted permanent-magnet motor from which cogging torque, electromagnetic torque and back-emf waveforms can be calculated as well.

Fig. 1 Studied tangential surface permanent-magnet motor. 2 Analytical Study Model. 1) A moving charge or current creates a magnetic field in the surrounding space (in addition to E). 2) The magnetic field exerts a force F m on any other moving charge or current present in that field.

- The magnetic field is a vector field vector quantity associated with each point in. Summary This chapter contains sections titled: Introduction Eddy Currents Domain Wall Velocity Switching in Thin Films Time Effects Magnetic Damping Magnetic Resonance Problems.with magnetorheological fluids.

When magnetic field is applied, the MRF varies from liquid to semi-solid state in just few milliseconds, so the outcome is an infinitely variable, controllable damper are capable of large damping forces[1]. The MR fluid is controlled by magnetic field using an electromagnet.