Modeling of Spinning Disk System for Charging Tendency of Ester-Based TiO₂Nanofluids Along with its Interfacial Zone

This article reports the static electrification of ester nanofluids for its use in transformers adopting the spinning disk model. The results show that the streaming current is higher for the nanofluid involving surfactant compared to its effect without surfactant. The streaming current observed is negative at the fluid-metal interface and positive at the fluid/pressboard interface. The streamline pattern along with surface velocity magnitude is simulated under different disk velocities using COMSOL and the convection current model is formulated for the identification of streaming current. The mass transfer rate with surfactant-based nanofluid shows a shift from transport regime to reaction limited regime at higher Reynolds number. Furthermore, the interfacial zone of nanofluids is discussed for the streaming behavior considering its influence with the addition of benzotriazole (BTA).