3D Propeller Design

[marufuddin0]

Hi, I would like to know how do you design a 3D propeller from 2D geometry,i.e. NACA profiles, blade sections?

 

[Heimfried]

I did it with Excel-VBA coded myself. Input parameters are about 20 additional to a table with the 2D blade section profile. Output was an .STL file. I was using the description of propellers given by the ITTC lexikon. The pic shows a section of a prop blade aligned to an appropriate cylinder barrel surface, divided in triangles (for .stl facet description) and containing incremental differences between the side outlines.
It is very laborious to workout the code.

Adding these sections it gives a blade.

boote-forum.de - Das Forum rund um Boote https://www.boote-forum.de/showthread.php?p=4909397&#post4909397

In the end the product looks like a propeller:

boote-forum.de - Das Forum rund um Boote https://www.boote-forum.de/showthread.php?p=4918090&#post4918090

 

[Will Gilmore]

Are you doing just the blade or the whole propeller? I suppose, once you have the blade worked out, you just attach it at the right points to the shaft.

I worked out a thread program simply by changing the rotation of the cross section as the Z axis increased. That was way back in AC12. Propeller pitch is a little more complicated, but I would think the basic concept would apply.

 

[Olav]

marufuddin0,

you might want to check out PropCAD by HydroComp.

 

[marufuddin0]

I did it with Excel-VBA coded myself. Input parameters are about 20 additional to a table with the 2D blade section profile. Output was an .STL file. I was using the description of propellers given by the ITTC lexikon. The pic shows a section of a prop blade aligned to an appropriate cylinder barrel surface, divided in triangles (for .stl facet description) and containing incremental differences between the side outlines.
It is very laborious to workout the code.
View attachment 163398

Adding these sections it gives a blade.

boote-forum.de - Das Forum rund um Boote https://www.boote-forum.de/showthread.php?p=4909397&#post4909397

In the end the product looks like a propeller:

boote-forum.de - Das Forum rund um Boote https://www.boote-forum.de/showthread.php?p=4918090&#post4918090

Hi,

Your workout way is entirely new to me. I am feeling curious to know how will you approach to design 3d propeller when you already know the 2D blade sectional geometry at different radius, i.e., r/R =0.2,0.3,0.4.....1

 

[marufuddin0]

Are you doing just the blade or the whole propeller? I suppose, once you have the blade worked out, you just attach it at the right points to the shaft.

I worked out a thread program simply by changing the rotation of the cross-section as the Z axis increased. That was way back in AC12. Propeller pitch is a little more complicated, but I would think the basic concept would apply.

I would like to design the whole propeller when I have all the sectional drawings of the blade.

 

[marufuddin0]

marufuddin0,

you might want to check out PropCAD by HydroComp.

Yeah, I know that, but I was thinking about designing in Rhino or AutoCAD.

 

[Heimfried]

[...] I am feeling curious to know how will you approach to design 3d propeller when you already know the 2D blade sectional geometry at different radius, i.e., r/R =0.2,0.3,0.4.....1
[...]

The 2D blade sectional geometry is given in Cartesian coordinates (x, y), first point is to interpolate the wide step between e.g. r/R = 0.2 and 0.3 in a suitable number of equidistant increments like e.g. r/R = 0.2; 0.205; 0.21; 0.215; ... Then define corresponding to the generator line the pivot point (percentage of chord) for rotating the section to the appropriate pitch angle (function of r/R). Transform the coordinates into 3D cylindrical coordinates (r, z, phi). r = constant, z = y, calculate the angle phi from x. Do the same with the next incremental section and transform both into 3D Cartesian coordinates. Connect the defining points in triangles as shown in the pic above to get a blade slice, the slices to get a blade, the blades to get a prop.