Propellers for all!

This release adds a new propeller component and fixes a pair of unrelated bugs. Though it may seem like a small change, the propeller component constructs its surface differently from other components. It represents a surprisingly large amount of work.

Instead of defining the blade shape (chord, twist) at specified stations, these are instead specified as continuious curves.

The propeller component comes with a bunch of related accessories — the blade activity factor is calculated on-the-fly, there is a one-click option to switch to a counter-rotating prop, propeller folding is built-in — with a user-defined fold axis, there is a blade element export/import capability, and the BEM data is available through the API.

Features:

• New propeller component
• Blade element import/export and API

Bug Fixes:

• Fix DegenGeom crash on Matlab export
• Fix GUI output of mass properties calculation