The idea is to design a fairly simple propeller using Fusion software program that has a CONSTANT airfoil throughout (but that twists or changes in scale as it spans). I want a large coefficient of lift (Cl) to coefficient of drag ratio (Cd). The Reynolds number should be about 28k. Calculated at radius=75% where the blade is most efficient at generating lift. Problem is the airfoiltools.com website shows the Cl to Cd graphs in a way that is not so easy to read. There is also no way to search through the output of the visual graphs. And I imagine scraping a visual thing like a Cl to Cd graph would be complicated. Any help? Regards

  • $\begingroup$ This might help $\endgroup$
    – sophit
    Mar 13 at 15:36

1 Answer 1


Regarding tools:

  • Digitizing data from plots is feasible, but it requires human effort.
  • The Airfoiltools website utilizes Xfoil, a free software that enables you to generate the necessary data (CL/CD) with any geometry. It may take some time to become accustomed to it.

Regarding the design-process:

  • Commercial drones are already optimized for a specific mission profile. If you need to increase the performance, be aware that you may hit other bottlenecks (battery, motors, software, controller, propeller clearance, etc).

  • Assuming you're going to 3D-print the propellers, remember that you'll also have structural/mechanical constraints.

  • A basic testing bench might help more than Xfoil and the optimization process you may try, if you have not designed propellers before.

If this is a class-work please share your current work and approach a bit more.

Tip: Comparing best CL/CD ratios is simple with human eye, or taking note of the top-left-most point and writing its CL and CD figures down.


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