Test Stand for the Examination of Magnetic Fluids in Shear and Squeeze Flow Mode

Abstract

The application of magnetic fluids in machine design on an industrial scale has been a fact for over 20 years. In particular, magnetorheological fluids have been used in energy dissipation systems with controlled operating characteristics. The availability of these fluids, connected with the ease of modelling their rheological properties by magnetic fields, contributes to the search for areas of effective use for such substances. Determining the properties and characteristics of magnetic fluid behaviour is one of the key aspects of improving existing and developing new applications for this type of smart material. Some phenomena affecting the behaviour of magnetic fluids have not been fully explained, and a synthetic model to describe their behaviour has not yet been developed, so the research area of this type of substance is still an open chapter for materials science. The paper presents a description of the design of a test stand for examining the behaviour of magnetic fluids working in shear and compression (squeeze) flow modes. Test results are also shown, and attention is given to the problems encountered in developing measurement systems for determining the properties of fluids under magnetic field conditions.

Analysis of the Influence of Magnetic Induction Ramp Profile on Axial Force and Friction Torque Generated by MR Fluid

“…The research experiments were performed on a test stand for the examination of magnetic fluids in shear and squeeze flow modes, described in detail in Horak et al (2017c). The scheme of the device is presented in Figure 1a.…”

“…On the edge of the core there is a local increase in the value. This provides the self-sealing effect [10] and the magnetic fluid is held in the region of the measuring gap. In turn, in the electromagnet core axis region, there are local decreases in the magnetic induction because of the opening present in the upper part of the test cell.…”

“…Therefore, before every measurement, a demagnetising procedure was carried out. Demagnetisation was accomplished by supplying the electromagnet coil with a sinus function decaying in time (see Horak et al, 2017c). This ensured the repeatability conditions under which the research was conducted.…”