Publication detail

Grasping the behavior of magnetorheological fluids in gradient pinch mode via microscopic imaging

KUBÍK, M. ŽÁČEK, J. GOLDASZ, J. NEČAS, D. SEDLAČÍK, M. BLAHUTA, J. BAŃKOSZ, W. SAPINSKI, B.

English title

Grasping the behavior of magnetorheological fluids in gradient pinch mode via microscopic imaging

Type

journal article in Web of Science

Language

en

Original abstract

Magnetorheological (MR) fluids are suspensions of micrometer-sized ferromagnetic particles in a carrier fluid, which react to magnetic fields. The fluids can be operated in several fundamental modes. Contrary to the other modes, the rheology and microstructure formation of the MR fluid in the gradient pinch mode have been studied to a far lesser extent. The magnetic field distribution in the flow channel is intentionally made non-uniform. It is hypothesized that the Venturi-like contraction is achieved via fluid property changes, leading to a unique behavior and the presence of a pseudo-orifice. The main goal is to investigate the presence of the Venturi-like contraction effect in the fluid by means of optical imaging and hydraulic measurements. To accomplish the goal, a unique test rig has been developed including a fluorescence microscope and MR valve prototype. The Venturi-like contraction hypothesis was confirmed. The results indicate that the effective flow channel size decreases by 92% at the maximum magnetic flux applied. This has a direct impact on the flow characteristics of the MR valve. The variation of the pressure–flow rate curve slope with magnetic field was demonstrated. The results provide valuable information for understanding the rheology and microstructure formation mechanism in MR fluids in the pinch mode.

English abstract

Magnetorheological (MR) fluids are suspensions of micrometer-sized ferromagnetic particles in a carrier fluid, which react to magnetic fields. The fluids can be operated in several fundamental modes. Contrary to the other modes, the rheology and microstructure formation of the MR fluid in the gradient pinch mode have been studied to a far lesser extent. The magnetic field distribution in the flow channel is intentionally made non-uniform. It is hypothesized that the Venturi-like contraction is achieved via fluid property changes, leading to a unique behavior and the presence of a pseudo-orifice. The main goal is to investigate the presence of the Venturi-like contraction effect in the fluid by means of optical imaging and hydraulic measurements. To accomplish the goal, a unique test rig has been developed including a fluorescence microscope and MR valve prototype. The Venturi-like contraction hypothesis was confirmed. The results indicate that the effective flow channel size decreases by 92% at the maximum magnetic flux applied. This has a direct impact on the flow characteristics of the MR valve. The variation of the pressure–flow rate curve slope with magnetic field was demonstrated. The results provide valuable information for understanding the rheology and microstructure formation mechanism in MR fluids in the pinch mode.

Keywords in English

magnetorheological fluid

Released

03.04.2024

Publisher

AIP Publishing

ISSN

1070-6631

Volume

36

Number

4

Pages from–to

042004-1–042004-10

Pages count

10

BIBTEX


@article{BUT188368,
  author="Michal {Kubík} and Jiří {Žáček} and Janusz {Goldasz} and David {Nečas} and Michal {Sedlačík} and Jiří {Blahuta} and Wojciech {Bańkosz} and Bogdan {Sapinski},
  title="Grasping the behavior of magnetorheological fluids in gradient pinch mode via microscopic imaging",
  year="2024",
  volume="36",
  number="4",
  month="April",
  pages="042004-1--042004-10",
  publisher="AIP Publishing",
  issn="1070-6631"
}