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

3. 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.

4. 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.

5. 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.

6. 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/MR_1.html http://rclsgi.eng.ohio- state.edu/~gnwashin/parts/MR_1.html  http://rclsgi.eng.ohio- state.edu/~gnwashin/parts/MR.html http://rclsgi.eng.ohio- state.edu/~gnwashin/parts/MR.html  http://rclsgi.eng.ohio- state.edu/~gnwashin/parts/MR_3.html http://rclsgi.eng.ohio- state.edu/~gnwashin/parts/MR_3.html  http://www.sciencentral.com/articles/view.ph p3?article_id=218392121&language=english http://www.sciencentral.com/articles/view.ph p3?article_id=218392121&language=english