This experimental study is conducted to explore the rheological behavior of magnetite-water ferrofluid in the attendance of an external magnetic field (MF). Tetramethylammoniumhydroxide is used as surfactant to increase the stability of prepared ferrofluids. The impacts of MFstrength (0–480 G) and volumeconcentration of nanoparticles (0.3–1.5%) on the outcomes are examined. It was found that as the shear rate increases, the viscosity decreases sharply and then tends to a fixed number and therefore, the magnetite-water has non-Newtonian pseudoplastic behavior. Itwas also found that the application of the MFboth increases the viscosity and enhances the non-Newtonian behavior of the ferrofluid. Moreover, itwas found that the rise of nanoparticle concentration (φ) leads to the increase of ferrofluid viscosity. Then, the artificial neural network is applied to develop a prediction model for the rheological behavior of water- magnetite ferrofluid in both the absence and attendance of an external MF based on the obtained experimental data. The outcomes revealed that the developed models are capable of predicting the outputs in the absence and attendance of an external MF with R2 value of 0.9772 and 0.9692.
