Squeezing Force of the Magnetorheological Fluid Isolating Damper for Centrifugal Fan in Nuclear Power Plant

Abstract

Magnetorheological (MR) disk-type isolating dampers are the semi-active control devices that use MR fluids to produce controllable squeezing force. In this paper, the analytical endeavor into the fluid dynamic modeling of an MR isolating damper is reported. The velocity and pressure distribution of an MR fluid operating in an axisymmetric squeeze model are analytically solved using a biviscosity constitutive model. Analytical solutions for the flow behavior of MR fluid flowing through the parallel channel are obtained. The equation for the squeezing force is derived to provide the theoretical foundation for the design of the isolating damper. The result shows that with the increase of the applied magnetic field strength, the squeezing force is increased.

Analysis and Testing of Chain Characteristics and Rheological Properties for Magnetorheological Fluid

“…Altering the strength of the applied magnetic field precisely and proportionally controls the shear yield strength of the fluids [1,2]. Based on the mechanical characteristics, the fluids can be used in the controllable energy-dissipating applications such as dampers [3,4], valves [5,6], and clutches and brakes [7,8].…”

Damping Force Modeling and Suppression of Self-Excited Vibration due to Magnetic Fluids Applied in the Torque Motor of a Hydraulic Servovalve

“…Therefore, the magneto-viscosity characteristics of the magnetic fluid applied in this paper were measured and are shown in Table 1 under the saturated condition. Assuming that the flow of magnetic fluids inside the gaps is steady and uncompressible, for the squeeze working mode of magnetic fluids in Figure 1, a bi-viscosity model in Equation (1) can be used to describe the constitutive characteristics of the magnetic fluid [26]: For the squeeze flow, the radial velocity (u r ) will decrease from the central plane to the upper and lower wall surfaces. Thus, the sign of ∂u r ∂x will always be positive, when x < 0.…”