The Effect of Ferrofluid on a Dilatant Fluid's Intrusion Resistance
Abstract
When small, macroscopic, solid particles (like glass beads or grains of starch) are immersed in Newtonian fluids (like water or glycerol), the resulting material demonstrates solidification under sudden driving, like from intrusion of an object above a threshold velocity. The physical means for this effect are not fully understood. One mechanism that has been proposed involves hydrodynamic pressure: the fluid must flow through the pore structure between particles as the material deforms. Consistent with this picture, the viscosity of the fluid has been identified as a contributing factor to this resistance. The ability to control the viscosity in real time would allow for maximum resistive pressure when needed and then for low resistance in between periods of high driving. One possibility for accomplishing this is using ferrofluids. Ferrofluids contain molecules of iron coated in a surfactant and suspended in a solvent. This mixture is capable of changing its viscosity when a magnetic field is present. I will explore the mechanical properties, including the impact resistance, where the simple Newtonian fluid is replaced with a ferrofluid. I compare this with existing data in literature and from previous projects in our group. I find that the experimental results match predicted theory to a point and then data suggests that other forces counteract these predictions. I find that ferrofluids are capable of creating a tunable complex fluid mixture and warrant further research.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2020
- Accession Number
- AD1127103
Entities
People
- Joshua M. Strader
Organizations
- Naval Postgraduate School