Thermal–electrohydrodynamic interaction in nano-encapsulated PCM suspensions for hydrogen-energy thermal management under periodic charge injection

This study numerically investigates transient thermal–electrohydrodynamic (EHD) convection of a dielectric nano-encapsulated phase change material (NEPCM) suspension within a thermal management module in hydrogen energy systems. The module consists of a square enclosure containing a centrally heated circular cylinder, while the NEPCM suspension provides convective heat removal and latent-heat buffering. The cylinder is subjected to periodic charge injection together with sinusoidal thermal excitation. The governing equations for fluid flow, heat transfer, electric charge transport, and electric potential were formulated using a single-phase NEPCM model with an apparent heat-capacity approach and were solved by the FEM. The results show that periodic charge injection strongly modulates the flow structure, charge distribution, phase-change region, and heat-transfer rate. Increasing the Coulomb force parameter intensifies EHD convection and amplifies the heat-transfer oscillations. Increasing the NEPCM concentration and introducing an appropriate phase shift simultaneously strengthen the time-averaged heat transfer and reduce the electrical power consumption. • Transient thermal-EHD convection of a dielectric NEPCM is addressed. • The formulation use single-phase NEPCM model with an apparent heat-capacity approach. • Increasing the excitation frequency alters the phase relationship. • A higher NEPCM concentration enhances thermal regulation through latent heat storage.