Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, St. John’s University, Queens NY, USA
Department of Physics, St. John’s College of Liberal Arts & Sciences, St. John’s University, Queens NY, USA
Department of Mechanical Engineering, POLY-NYU, Brooklyn NY, USA
Engineering School, Abu Dhabi-NYU, Abu Dhabi, UAE
Abstract:
Capillary dynamics of nanofluids under external magnetic fields is indispensable in biomedical applications. Nanofluids are stable colloidal suspensions of nano-sized magnetic particles. A uniform nanofluid under a magnetic field is influenced by (i) magnetic forces (ii) viscous drag forces (iii) thermal kinetics (iv) fluid particle interactions, and (v) capillary diameter. We assume a quasi-continuous flow such that, except at the capillary locations of predominant magnetic field, all physical properties (kinetic and thermodynamic) of the nanofluid remain constant. The negligible mean free path of the fluid compared to the average nanoparticle size supports our continuum model. The uniform motion of the nanofuid is verified by both Reynold’s (Re) and Knudsen (Kn) numbers being less than unity. We numerically calculate the retention rate of the magnetic nanoparticles under an external magnetic field for the variations in the physical and geometrical parameters by considering magnetic and fluidic forces. We implement a stochastically variant Monte-Carlo algorithm to simulate the dynamics of the capillary-fluid. We examine the validity of the uniform-continuous fluid model as a function of temperature. Finally, we compare our computational results with an in vitro experiment where oleic acid coated magnetic nano-particles dispersed in 2% methocel solution pass through capillaries at different magnetic field strengths.