Assessment of Two Electro-Rheological Fluids for Use in Recoil Abatement Applications
Abstract
The electrical and rheological properties of two state-of-the-art electro-rheological (ER) fluids have been evaluated from 0 to 60 deg C, using a unique constant-stress viscometer. The measurements were performed at the facilities of ER Fluid Developments, Ltd. (ERFD), a small British company located in Sheffield, United Kingdom, that specializes in developing and marketing ER fluid-based technology. In addition to these measurements, the response time of the fluids was determined using another instrument located at the nearby University of Sheffield. The constant-stress viscometer, or dynamic rig, developed and owned by ERFD, permits the yield stress, plastic viscosity, and direct current (DC) current density of an ER fluid to be determined as a function of electric field and temperature. The yield stress, plastic viscosity, current density, and response time of each fluid were found to strongly depend on temperature. The first fluid appears to be stronger (i.e., has a higher yield stress), with lower current densities at lower temperatures up to 40 deg C. In that temperature range, the second fluid is somewhat weaker, susceptible to electrical breakdown at or above 2.0 kV/mm, and generally draws more current At higher temperatures, however, the current density of the first fluid dramatically increases to exceed the desired level of 10 mu-A/sq cm. The corresponding current density increase of the second fluid is significantly smaller. In light of the differences between the measured properties, the results and their implications associated with the intended use of the fluids are discussed. A general description of ER fluid behavior, as well as the theories of operation of the instruments, are also described.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2001
- Accession Number
- ADA390995
Entities
People
- Laszlo J Kecskes
Organizations
- United States Army Research Laboratory