Simple yet Powerful universal turbine - 2 Parts, for all motors.

thingiverse

This turbine is incredibly robust and versatile, capable of working seamlessly with almost any DC motor. By design, it's an exceptionally straightforward device that requires minimal components. The fact that all the air either exits directly or rebounds off its casing contributes significantly to its exceptional strength. As a result, the airflow emerges in a perfectly linear fashion, making it ideal for use on boats, submarines, and aircraft. Its uncomplicated shape also allows for effortless resizing to accommodate larger or smaller motors, as well as easy modification when necessary.