Magnetorheological Fluids

1
Magnetorheological Fluids

• Jaime Niño Jr.
• MEEN 3344
• FALL 2005

2
Functions of MR Fluids

• These 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

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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.

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Applications of MR Fluid

• Vehicle 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.

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Cont Applications

• MR 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.

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Advantages Of MR Fluid

• Easy to control
• As magnetic fields can be precisely controlled
  by current driven electromagnets
• Have higher magnitude of yield stress
• Compared to ER fluids the simple construction of
  devices, low power requirements for control, fast
  response

7
References

• http//rclsgi.eng.ohio-state.edu/gnwashin/parts/M
  R_1.html
• http//rclsgi.eng.ohio-state.edu/gnwashin/parts/M
  R.html
• http//rclsgi.eng.ohio-state.edu/gnwashin/parts/M
  R_3.html
• http//www.sciencentral.com/articles/view.php3?art
  icle_id218392121languageenglish