Dynamics research on magneto-thermo-mass-fluid–structure multi-physics fields

This work investigates the combined effects of transverse magnetic fields, wall conductivity, inlet flow velocity and wall thickness on magnetohydrodynamic (MHD) flow, heat transfer and mass transport within a vertical duct, as well as the mechanical performance of the conductive duct wall. A multi-region simulation platform based on the finite volume and the finite element methods is developed to model magneto-thermo-mass-fluid–structure coupling. The results indicate that, when the wall conductivity is low, the coupling effect between the magnetic field and the wall conductivity exhibits a magnetic-field-dominated mode. The magnetic field suppresses jets and reverse flow, with the maximum velocity scaling as Urmγc+1∼Ha−1/2 and the vortex center height scaling as Hv∼Ha1/3. Mass permeability and inventory decrease exponentially with increasing magnetic field strength. Thermal stress peaks at the Hartmann wall outlets, with a transition from disordered to regular temporal fluctuations as the magnetic field strength increases. The variation laws differ at high wall conductivities. A higher inlet velocity compresses the reverse vortices toward the outlet. The maximum reverse velocity decays as Urm∼lg(Re−1). It enhances convective heat and mass transfer, resulting in lower mass permeation and retention, as well as a monotonic reduction in solid wall stress. Thicker walls can weaken the right jet and reverse flow, raising the system temperature and local concentration, which enhances fluid-to-solid mass permeability and solid inventory and increases outlet stress. The maximum stress satisfies σMises,max/σy ∼ th/a. This work improves the understanding of MHD duct flow and provides a foundation and support for engineering design and structural analysis.