Study and optimization on the ferrofluid seal with Sandwich magnetic circuit

This study proposes a novel ferrofluid sealing structure employing a sandwich magnetic circuit (FSMC), distinguished by the integration of an additional permanent magnet within the shaft sleeve cavity to significantly enhance sealing capability. Finite element (FE) simulations were conducted to evaluate the magnetic field distribution and corresponding pressure resistance of the FSMC, with the modeling approach validated against previously published experimental data. Response surface methodology (RSM) was subsequently applied to systematically optimize key geometric parameters and investigate the interactive effects of these parameters on seal pressure resistance. The findings demonstrate that the FSMC configuration significantly improves the sealing performance, achieving increases in pressure resistance ranging from 7.86 % at a seal gap of 0.2 mm to 18.94 % at 1.0 mm, compared with conventional ferrofluid seals (CFS). This study provides a guideline and systematic design approach for ferrofluid sealing applications. • Proposed a novel ferrofluid seal with a sandwich magnetic circuit (FSMC) design. • Combined finite element analysis and experimental validation for pressure resistance. • Optimized key parameters via response surface methodology improving sealing by 21.9 %. • FSMC achieved average enhancement to 11.59 % higher pressure resistance than conventional ferrofluid seals.