A mathematical model of cavitation behaviour in a single-ended magnetorheological damper: experimental validation

Abstract

This paper proposes a mathematical model of the cavitation behaviour to occur in a single-ended magnetorheological damper (MRD), and the effectiveness of the model is validated through the comparison with experimental results. Several causes of the cavitation behaviour of MRD are discussed with different conditions of the initial pressure of the gas chamber and the piston stroke speed. The model to capture the cavitation behaviour is then formulated considering differential equations for gas volume, internal pressure, ideal gas law and bulk modulus of MR fluid. In order to calculate the flow rate, which is difficult to solve from the differential equations, the model is approximated as a nondimensional equation the parameters of the yield stress and pole length. Subsequently, the field-dependent damping force of MRD is computed using gaseous cavitation model and nondimensional equation. To validate the proposed cavitation model, a single-ended MRD is designed, manufactured and tested. It is firstly observed that the damping force characteristics under cavitation are revealed to be much different from those under normal operation without cavitation. More specifically, it is hard to calculate the dissipation energy and hysteretic damping due to highly nonlinear characteristics with respect to the stroke and velocity. However, the proposed model can fairly capture the cavitation behaviour showing an excellent agreement between simulation and experiment. In this work, to confirm the internal influence of MRD by the cavitation, which is difficult to experimentally confirm, the changes of the pressure distribution and the gas-to-liquid volume ratio are analyzed through the simulation of the nondimensional equation. In addition, the bubbles representing the cavitation behaviour are visually observed from the lower chamber of

Theoretical switch model of novel asymmetric magnetorheological damper for shock and vibration application

“…According to the CFC-MRD structure, the gas compensation force can be obtained by establishing the force balance equation for the floating valve as an object and combining it with the ideal gas equation [47,48]…”

Aircraft landing gear system with magnetorheological shock strut: Performance evaluation via drop test

“…Hence, the major loss is considered only acting on the annular orifice and bypass in the extending condition. Under the extension, the relations between flow velocity and pressure loss in the orifice and bypass are as follows (Kang et al, 2022):…”

“…The entry length is long enough so that the magnetic core in Figure 3 is not located in the entrance region (Yang et al, 2002), installed to one side only since the region is negligible during extension. Besides, the effects of fluid compressibility and hydrodynamics are disregarded since there is a minor error between the cavitation model (Kang et al, 2022) and the model to be described later, and it is meaningful to prove and secure the model validity of the pressure loss model.…”

“…MREA capable of resting an impulse of up to 300 NÁs within 30 ms was built based on a nonlinear hydrodynamical model, and the transient impact response has been analyzed experimentally (Mao et al, 2013). Moreover, recently the cavitation behavior was mathematically modeled for the MR damper, and its effectiveness was validated via experiment; It is observed in the MR damper that the hysteresis damping is dependent not only on the effect of the magnetization but also on the cavitation effect (Kang et al, 2022).…”

Study on the influence of composition parameters of magnetorheological fluid on its vibration transmission characteristics

“…It can quickly and reversibly change its material parameters when subjected to a magnetic field [2]. Based on this characteristic, many MR vibration control devices have been developed and widely used [3][4][5]. The vibration transmission characteristics of the MRF refer to the vibration energy loss when external excitation at different frequencies propagates in the MRF [6], representing the vibration attenuation performance of the MRF.…”