Hi All,

Normally I don't go around playing "salesman" touting a particular product. This will be an exception, as I'll give credit where it's due (I have no affiliation to the product / person).

Anyone designing model aircraft, or otherwise interested in airfoil selection and performance comparisons, should look at Profili 2.0 (and its price ==> $10 ).

The author, Stefano Duranti, has released a new version (latest is 2.03d as of this writing) that will generate polars for any of the 2200+ airfoils in its database (which can all be modified, e.g. change camber, thickness, etc), or for any custom airfoil per user-entered coordinates.

Now, priced at $10, you're probably thinking "The analysis capability can't be very sophisticated," however consider that the analysis engine built into Profili is the well-known XFoil program by Dr. Mark Drela, professor of Aero / Fluids at MIT, whose research specialty is computational aerodynamics. Basically, Profili delivers the power of XFoil in a user-friendly format, coupled to an extensive airfoil database. In addition, XFoil's processing parameters can be modified via a Windows menu.

Just a few mouseclicks generates not only standard polars, but multi-airfoil comparison plots, or plots of various combinations of Cl, Cd, Cl/Cd, Cm, AOA, Re.

Given the complexity of CFD analyses, even if not highly accurate in terms of actual numbers, the results can be insightful for comparative purposes, or to see effects of modified airfoil geometries, different Re, etc.

No doubt Profili will continue to evolve, but this version 2 marks a huge refinement over the previous version dealing with airfoil geometry alone.

Get Profili here: http://www.profili2.com

Below are a couple Profili outputs (I pasted the legend; it actually appears above the charts).

Here's a standard polar of 5 airfoils at Re = 70000, predicting low-Re breakdown of the E387 & Zagi 12: