Effect of surface modification on steady flow past a stationary circular micro-cylinder

The method of moments is used to study flow past a stationary circular micro-cylinder and the impact of modifying the cylinder’s surface properties. In the creeping flow regime, the total drag is only affected slightly by the variation of the surface accommodation coefficient. As the cylinder surface becomes more specular, the stress components, normal and tangential, tend to cancel each other out and the drag effectively becomes a function of pressure. A further observation is that a smoother surface will delay the onset of flow separation and vortex formation and acts to reduce the length of the attached downstream vortices for a fixed Reynolds number and Knudsen number.