Numerical simulation of gas flow over micro-scale airfoils

Flows over micro-scale airfoils are investigated using both particle and continuum approaches. An implementation of the information preservation technique based on the direct simulation Monte Carlo method is used to simulate flows over a flat plate of zero thickness at low Reynolds number (Re<100), and good agreement is obtained comparing with experimental data and theoretical results. Investigation shows that the aerodynamics of a 5% flat plate at Re=4 is quite different from that at Re=4,000 that were measured experimentally. A continuum approach with slip boundary conditions predicts a similar basic flow pattern as the IP method with differences in details, which may indicate that continuum approaches are not suitable for this kind of flow because of rarefied effects.