10-04-2017, 09:09 PM
ABSTRACT
The Magneto Hydro Dynamic (MHD) propulsion thruster is designed to use magneto hydrodynamic force generated by sending electric current through a magnetic field created in sea water by superconducting magnets. The principle of MHD propulsion is to apply the Fleming's left hand rule of electromagnetics to sea water directly .In this propulsion system magnetic field is created in sea water by magnets fixed on a hul1. When electric current is sent to sea water at right angles to the magnetic field, and electromagnetic force (Lorentz force) acts on sea water in the direction perpendicular to both the direction of magnetic field and that of electric current. Propu1sion force is gained as a reaction force of this Lorentz force.
INTRODUCTION
MHD
Magneto hydrodynamics involves magnetic fields (magneto) and fluids (hydro) that conduct electricity and interact (dynamics).MHD technology is based on a fundamental law of electromagnetism: When a magnetic field and an electric current intersect in a liquid, their repulsive intersection propels the liquid in a direction perpendicular to both the field and the current. Hannes Alfven was the first to introduce the term MHD.
Thruster
The Magneto Hydro Dynamic (MHD) propulsion thruster is designed to use magneto hydrodynamic force generated by sending electric current through a magnetic field created in sea water by superconducting magnets. The principle of MHD propulsion is to apply the Fleming's left hand rule of electromagnetics to sea water directly .In this propulsion system magnetic field is created in sea water by magnets fixed on a hul1. When electric current is sent to sea water at right angles to the magnetic field, and electromagnetic force (Lorentz force) acts on sea water in the direction perpendicular to both the direction of magnetic field and that of electric current. Propu1sion force is gained as a reaction force of this Lorentz force.
The Lorentz force F (N) which is the source of thrust force T is given by the formula
F = J X B dv (N)
Here J is a current density vector of infinitesiml volume dv and B is a magnetic flux density vector of the same. When J and B are constant over the entirevolume V (m3) of the working part where magnetic fie1d and electric current interact, can be expressed by the fol1owing formula
F = J X B X V (N)
Thruster Systems
The magnetohydrodynamic (MHD) thruster system for ships with superconducting electromagnets has been recognized as its potentially attractive performance. Namely, it does not need any rotating part like conventional propellers or water jet propulsions, and therefore may
be less affected by cavitations, which would be suitable propulsion means for high speed ships and for ships as specially required silent operation. However, it is still considered that the MHD thruster system has various kind of difficult problems to be resolved before it could reach
the level of practical use. The problems may be classified into two categories, which are the technology specifically concerning physical phenomena of superconductors and practical technique which examines possibility for designing and constructing MHD thruster systems. This investigation concerns with the later kind of problems. It is considered that MHD thrusters can be designed
Conclusion
The Magneto Hydro Dynamic (MHD) propulsion thruster is designed to use magneto hydrodynamic force generated by sending electric current through a magnetic field created in sea water by superconducting magnets. When electric current is sent to sea water at right angles to the magnetic field, and electromagnetic force (Lorentz force) acts on sea water in the direction perpendicular to both the direction of magnetic field and that of electric current. Propu1sion force is gained as a reaction force of this Lorentz force.MHD propulsion is very advantageous as
it consists of no moving parts and it is pollution free. In the near future this propulsion device will be used over the conventional propulsion devices.
MHD Propulsion Thruster Ship (Download PPT,Report,Abstract)
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