Tutorials, training, and best practices for designing and analyzing with Open Vehicle Sketch Pad
This tutorial covers the propeller Rake and Skew parameters. In contrast to Sweep and Axial, the Rake and Skew are always relative to the local chord orientation rather than the propeller plane of rotation where Rake is normal to the chord and Skew is parallel to the chord. For more information about how to manipulate these curves, please refer to the Propeller Blade Control Curve Interface page.
The propeller blade Twist curve is defined by the distribution of twist angles in degrees along the blade and the curve type. For more information about how to manipulate these curves, please refer to the Propeller Blade Control Curve Interface page.
The propeller blade Chord curve is defined by the distribution of chord-to-radius (C/R) values and the curve type. For more information about how to manipulate these curves, please refer to the Propeller Blade Control Curve Interface page.
This tutorial introduces the propeller blade control curve interface including how to change the curve type, add or remove control points, interact with the curves, and changing values manually. Note that a propeller with many control points will tend to update slowly so you should only use as many control points as needed to obtain the desired profile. An imported BEM model will likely have too many points to function effectively. However, you can choose an Approximate Cubic Bezier to significantly reduce the number of points and automatically convert to a Bezier curve.
In this tutorial, we will discuss how to apply pre-cone and how to alter the construction and feather axes to change how the propeller blades are built and rotated. The construction axis, defined by Construct X/C, is how the blade airfoils are placed relative to one another by a chord percentage. For example, a value of 0.0 will align all airfoils at their leading edges while a value of 0.25 will align the airfoils at the quarter-chord location. The feather axis, in contrast, controls where along the blade root chord the feather axis passes through the blade. The entire blade will shift along the root chord direction relative to a fixed feather axis.