INTRODUCTIONViscosity controlled by the application of a
Magnetic Field.Viscosity directionally proportional to the strength
of Magnetic field.Viscosity change is achieved in a fraction of a
millisecond.Viscosity can be altered several times with fluid
properties unaltered.Variety of applications.Numerous
Advantages
More info - MR FLUIDS?Tiny Iron Particles align with Magnetic
Field.Fluid turns pasty and feels very stiff.Reverts to liquid when
Magnetic Field is removed.The weight and space required by the
coils to produce magnetic field is a setback.
Functions of MR FluidsThese are liquids that change their
properties when we apply a magnetic field to them.When the magnet
is in place the MR Fluid turns into solid. When the magnet is
removed the solid instantly reverts to liquid
What is MR fluid?Soft magnetic material in a carrier oil.Silicon
oil or even corn syrup is mixed with the MRF to prevent
rust.Typical MR fluid contains 20-40% by volume of relatively pure,
soft iron particles.Rheology or to the phenomena of flowing matter
Is type of rheological fluids whose yield stress can be varied by
an applied magnetic field.A typical MR fluid consists of micron
sized magnetizable iron/ferrous particles suspended in a base fluid
like silicone oil or water.
Applications of MR FluidVehicle Suspension Dampers
The MR damper has a built-in MR valve across which the MR fluid
is forced. The piston of the MR damper acts as an electromagnet
with the required number of coils to produce the appropriate
magnetic field. Also the MR damper has a run-through shaft to avoid
an accumulator.
Cont ApplicationsMR Transmission Clutches
They are used in automotive power train to transmit torque from
the engine to the transmission and the vehicle. The MR sponge
clutch may be used to provide launch control of an automobile
thereby achieving smooth vehicle launch. The MRF clutch thus may
replace the existing torque converters and therefore help increase
the fuel economy.
MRF Demonstration Stator and a Rotor Coiled copper wire on the
rotor to make an electromagnetBrushes-Commutator Assembly Shaft to
rotate Wheel to experience resistance.
Home-Made Magnetorheological Fluid
Cross-Sectional View
FINAL ASSEMBLY260 copper wire coilsBrushesWires connecting to
Power SourceWheel
Do It Yourself MRF55 g Multipurpose Oil + 5 g of White Lithium
Grease
+Add 150 g of Iron filings
Advantages Of MR FluidEasy to controlAs magnetic fields can be
precisely controlled by current driven electromagnetsHave higher
magnitude of yield stressCompared to ER fluids the simple
construction of devices, low power requirements for control, fast
response
Referenceshttp://www.liquidsresearch.com/products/magnet.asphttp://www.sciencentral.com/articles/view.php3?article_id=218392121&language=englishSynthesis
and properties of MR FLUIDS by Seval Gen
