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Matthias Maasch

How to close the propeller blade tip

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Hi all,

 

for viscous flow computations it is necessary to have a  watertight geometry. For this reason I created two features which closes the blade tip of the blades which were created with our blade engine.

 

1. Feature:

 

  • I created a fillet curve above the blade gap

post-45-0-00333900-1375276516_thumb.png

  • with the fillet curve I created a lofted surface which closes the gap

post-45-0-57146100-1375276940_thumb.png

 

2. Feature:

 

  • I created a nurbs curve which depends on the fillet curve from the 1. Feature

post-45-0-40520400-1375277077_thumb.png

  • the two inner points of the nurbs curve are located on the fillet curve
  • you can change both the position of the points onto the fillet curve and the weights of the points

post-45-0-33019700-1375277737_thumb.png

  • with the nurbs curve I created a lofted surface which closes the gap

post-45-0-67429300-1375277830_thumb.png

  • so you have more control over the surface shape but also you do not have a tangential transition between the blade surface and the tip surface

If you are interested in viscous flow computations with our blade/propeller definition please give feedback to these features if it work good or not. I think I will improve the method within the next days (or weeks).

 

Cheers

 

Matthias

closedBladeTip.fdf

closedBladeTipNurbs.fdf

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Hi,

 

please find attached a new try to close the propeller blade tip (a feature and a sample project). This time I created a thin ruled surface (red) based on the fillet curve which I rotate with a small angle. With this ruled surface it is possible to create two fillet surfaces (green and blue). So it is possible to transfer all tangent informations to the blade tip. Within the feature you are able to control the rotation position of the ruled surface based on the fillet curve, the thickness of the ruled surface and the tangents between the fillet surfaces and the ruled surface.

 

post-45-0-88969900-1375536127_thumb.png

 

(The ruled surface (red) should be very thin, Cap thickness= 0.001)

 

post-45-0-93985000-1375536315_thumb.png

 

Problem: Since the two basic image surfaces of the blade are not valid the fillet surfaces have the same problem.

 

Cheers

 

Matthias

closedBladeFilletSurf.fdf

BladeTip.fdb

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Hello,

 

How do you open the .fdf files? I tried opening it using CAESES-FFW but it would not open. I am currently making a cleaving propeller for a senior project and I need to close the tip of the blade in order for the CNC machine at my school to be able to read the file to manufacture the propeller. My skills with CAESES are still very poor and I was not able to close the tip of the blade based on what you wrote in this thread. 

 

Can you provide any additional guidance for me on this topic, possibly a youtube video or a more detailed guide? I would greatly appreciate it. If you have any questions for me I would be more than happy to respond.

 

Thank you. 

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HI Kevin,

Download the .fdf and save it in on of your "feature" directories. You can also create a new directory for your own features and activate it for the menu in the file | settings | features

Cheers

Claus

post-20-0-33918000-1413270530_thumb.jpg post-20-0-44148900-1413270545_thumb.jpg

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Hi folks,

 

please find below another approach how to close the blade tip. In order to provide a fully tangentially transition between all surfaces, I devided the blade into a few parts, namely Leading Edge, Trailing Edge, Suction Side and Pressure Side. As a first step, I connect the Leading Edge and the Trailing Edge with a Fillet Surface. Then, I close the two gaps at the Suction Side and Pressure Side again with Fillet Surfaces. This approach seems to pretty stable in terms of a variable geometry.

 

Please see some pictures from different views:

post-45-0-99392000-1416260480_thumb.png Tip from the top-view

post-45-0-04886900-1416260546_thumb.png Tip from pressure-side-view

post-45-0-59405100-1416260571_thumb.png Tip from suction-side-view

post-45-0-33335100-1416260610_thumb.png Tip from leading-edge-view

post-45-0-41701400-1416260641_thumb.png Tip from trailing-edge-view

 

But have  a look by yourself folks. Attached you can find the project, including a propeller as trimesh (STL) and BRep (IGES).

 

Propeller_Tip.fdb

 

Cheers

 

Matthias

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Check out this blog post which comes with a video. There is a feature included now in CAESES (>4.1.2) which does the job with a single click. Nothing else is needed, it is super easy.

 

Cheers

Jörg

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Quick question:

 

I can create the tip for a single blade but when I use that blade to create a propeller I can not transform the tip together with the blade. So the propeller is still tipless. I did watch the videos and search the documentation but apparently I am missing something. What could be the correct way of using blade tip for the propeller?

 

thanks in advance

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Hi Engin,

 

I'm not really sure about your setup but this should be really simple. For instance, if you put the tip together with the blade surface into a brep, you can then transform the whole thing. Since you are a customer, you can use the helpdesk to submit your example and we can help you very quickly.

 

Joerg

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Hi all,

I have been trying to close the blade and the blade tip of my propeller, but do not know how to do it. I am using the NACA-4DS profile. I need it for vicous simulations in starccm+.

I would really appreciate some help with this issue.

Thank you in advance!

Alejandro

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