Boundary Drag Force Acting on an Impenetrable Nano-Particle

Flow over nano spheres is a fundamental problem encountered in many engineering technical problems and the motion of nano-particles is important in many technical areas, for example nano-organizms motion in aqueous media, super hydrophobic spray for coating materials, nano-capsules for detecting cancer, and additive nano-particles in oil and fuel for automotive engines. In this paper computations are performed to determine the steady flow forces acting on the stationary nano-tube for Reynolds numbers in the range of 0.1<Re<40 and 0.01<Kn<0.1 with the slip boundary condition. A single dimensionless parameter, the so-called slip number (Tr), is defined to account for the slip at the nano-particle boundary., Increasing slip causes to delay of flow separation around the nano-tube surface. Numerical results confirm that slip variations can not affect on the drag coefficient values at low Reynolds regime. At higher Reynolds number increasing slip causes to drag reduction of flow around the Nano-Tube.