The previous section implemented and charted the ping-pong polar diagrams in a spreadsheet and showed a reasonable similarity, for moderate angles of attack, between these diagrams and the ones modeled using Xflr5, a virtual wind tunnel. This section introduce theĀ concept Reynolds number and it also contains a very brief introduction to Xflr5, the free virtual wind tunnel software. Aerodynamics… Read More... "Aerodynamics Naive #3 – a brief introduction to Xflr5, a virtual wind tunnel"