aero495 magnetorheological fluids mrf
TRANSCRIPT
Magnetorheological Fluids
Dr. Mohammad Tawfik
MR Fluids
How do they work?• Externally applied magnetic field
in a direction normal to the fluidflow direction form dipoles in theiron particles
• Magnetic poles start attractingeach others to the direction of thefield, hence forming chains
• The chains then form a skeletonwithin the fluid, which gains thefluid controllable yield stress
Why MR technology?
Required Materials to synthesize an MR fluid:
• Lithium grease
General purpose oil
Micron-sized iron particles
MR Fluids
Rabinow and Winslow 1950’s
MR Damper Fabrication
Prototype Damper
Seat Shock Absorbers
Modes of Operation
Damper – Valve Mode
Damper – Valve Mode
Clutch – Sheer Node
Structural Damping
Yield Sheer Stress Variations
Rate of Strain with Filed
Homework #4
• Summarize chapter 4 in no more than 5 pages
• Present a derivation for the equations whenever it seems appropriate.