The influence of multi-magnetic-source comb-like cooling structure on the performance of magnetic fluid seal

To address increasingly stringent high-speed sealing requirements in military and aerospace applications, a multi-source magnetic fluid seal with a comb-like cooling structure is proposed. Increasing magnetic sources forms a multi-pole configuration with comb-like grooves, enhancing heat dissipation and optimizing magnetic field distribution. Using ANSYS finite element simulation, the effects of magnetic source arrangement, magnetic induction coercivity, aspect ratio, and groove depth on sealing performance under magneto-thermal coupling were analyzed. Results show an average magnetic flux density gradient difference of 0.57 T per pole tooth and a maximum sealing pressure of 561.6 kPa, 12.1% higher than conventional seals. At 8000 r/min, the maximum operating temperature of the magnetic fluid drops from 64.1°C to 47.3°C compared to that in the conventional structure (a 26.2% reduction), while the sealing pressure increases from 447.4 kPa to 527.1 kPa (a 17.8% increase), indicating significantly improved heat dissipation and sealing performance. Optimal performance is achieved with series arrangement, relatively low magnetic induction coercivity (661 kA/m), aspect ratio of 2, and groove depth of 17 mm. This study provides a theoretical basis and structural reference for magneto-thermal collaborative design of magnetic fluid seals under high-speed and heavy-load conditions in aerospace engines and marine propulsion systems.