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---------------------- Propellers ------------------------------

This is a META-thread, which helps you to keep track of all posts relevant to Propellers.

 

- The first post should contain links to all relevant threads. It is re-edited regularly.

- I try to keep this META up to date. However, I don't always catch everything, so please post links to any threads you think should be here. I will add them to the existing ones in the first post and periodically clean all other post from this thread.

 

Thanks,

Mattia

 

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Hello,

 

I am a senior mechanical engineering major in college working on a solar boat for my senior project. My task on this team is the propeller design. Our plan is to manufacture a cleaving propeller to be used in a surface piercing configuration. Currently, I have a CAD model of the tutorial propeller that came with the free version of CAESES. 

 

My question is, how do I create the "straight" trailing edge characteristic of cleaving propellers? I have played with the variables: rake, skew, pitch, chord, and thickness, but I cannot create the geometry I am looking for. Can anyone in here provide me with some assistance?

 

I apologize if this post is in the wrong place or not specific enough. I will provide any and all information I can if it is needed to answer my question. Thank you.

 

Also, I have attached the .fdbc model of my propeller to this thread. 

TutorialBlade.fdbc

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Hi Kevin,

You can simply replace the skew function in the blade object by a genericCurve which depends on the chord function.

x: chord.getPos(t):x,

y: -0.5 * chord.getPos(t):y

z: 0

 

Then the trailing edge will be a straight line, no matter which chord distribution you have.

You might want to change the profile to one with a sharp leading edge. Please check out the youtube video on replacement of a profile for propellers.

http://www.friendship-systems.com/products/friendship-framework/videos/propeller-profile-design

 

Cheers

Claus

 

straightTrailingEdge.fdbc

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Hi Gianluca,

 

You can e.g. create an imageSurface on top of the blade and then either "swap domains" or change one or both of the domains individually i.e.  [1,0].

You can also split the sides or edges in seperate surfaces by adoping the domains. Be aware that the exported ImageSurface finally will interpolate the triangulation that you select (u-resolution, v-resolution).

 

Cheers

Claus

post-20-0-66898000-1413382466_thumb.jpg

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Hi
As a part of my research work i am preparing ship model and propeller. KCS ship has been taken for the reference study which is readily available in internet.I am facing some problem with the propeller modelling due to lack of iges or offset files.
I have free licensed software caeses with me. And i observed that there is a 3 meter diameter propeller with NACA66 section is available in the software. I tried to scale down it to my propeller diameter which is 0.105 m with NACA66 profile.But the pitch and other datas are seemed to be different.Is there any way in which i can modify the propeller to my requirement.
Following are the requirement.
 
 r/R       P/D      Rake           Skew(¡£)    C/D         fo/C       to/D 
0.180   0.834700   0.0000     -4.720   0.231300   0.028448   0.045850 
0.250   0.891200   0.0000     -6.980   0.261800   0.029641   0.040710 
0.300   0.926900   0.0000     -7.820   0.280900   0.029477   0.037120 
0.400   0.978300   0.0000     -7.740   0.313800   0.026769   0.030470 
0.500   1.007900   0.0000     -5.560   0.340300   0.022010   0.024590 
0.600   1.013000   0.0000     -1.500   0.357300   0.017324   0.019470 
0.700   0.996700   0.0000      4.110   0.359000   0.014039   0.014920 
0.800   0.956600   0.0000     10.480   0.337600   0.011996   0.010730 
0.900   0.900600   0.0000     17.170   0.279700   0.010440   0.006930 
0.950   0.868300   0.0000     20.630   0.222500   0.010067   0.005280 
1.000   0.833100   0.0000     24.180   0.000100   8.700000   0.003690 
 
It will be a great help for my future work if you can help me out from these situation with a reference ,tutorial etc.
 

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Hi,

I am trying to design kvlcc2 propeller in caeses. I followed the tutorial of propeller and tried to design the kvlcc2 propeller  in caeses. I have got few problems while doing design, I was unable to do hub and root fillet and trimesh also. I  attached the file that I did. can someone help me how to do?

kvlcc2 propeller.fdbc

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Hi Surya,

 

It seems that your profile flipped somehow, probably some of your functions are not correct. Leading edge seems to be trailing edge when looking at the blade.

 

You can also check out the axial fan example where some Boolean operations are included plus the filleting. The propeller example that is shipped with CAESES has a tip feature to close this region as well. The blade surface at the hub needs to be extended by using the Brep Surface extension for surfaces (in v-min-direction) to have an intersection of the blade with the hub.

 

As soon as you have the solid hub plus a single blade, you can use the attached feature to create the full propeller. It simply rotates the single blade hub object N times and does a Boolean Operation.

 

 

post-8-0-70700600-1501685760_thumb.png

BRepPeriodicBlades.fdf

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Thank you Joerg for your reply. As u mentioned I noticed that some of my functions were not correct. So I had started modelling from the data available from internet and finally got the blade geometry ready.

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Hi Jai,

 

I have contacted you directly for the Wageningen B-Series propeller.

 

Cheers

Joerg

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Hello,

 

I am studying Naval Architecture and Marine Engineering at NTUA. This period i am doing my diploma thesis on Parametric Modeling of Marine Propellers and i am using the online tool of Caeses for generating Wageningen B -series Propellers. Until now this tool was great guide for me, but i would like aslo to check more details about the geometry of B-series. So it would help me a lot, if you could upload or send me this project to a .fdb file.

 

Best regards.

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Hi,

 

The Wageningen setup is a project file which we do not simply distribute (we have spent a substantial amount of time to set it up). Instead, we sell it as it is or in a customized version to our CAESES customers. 

 

What details do you need to check, i.e. what do you like to investigate further?

 

Cheers

Joerg

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The skew values are defined by the b-series which is the reason why we do not expose the possibility to change it in the "simple" web app. However, our implementation contains a possibility to add delta skew values to the distribution for more flexibility. Maybe your supervisor can get in touch with us through our website to discuss this further. Sorry for not having a quick solution right away. BTW: Do you really need b-series or do you also consider other profile definitions? As you probably know, CAESES comes with a demo propeller model which can be customized. If you start from this, it should not be that complicated to come up with a propeller for your work.

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Hi,

I am a postgraduate student majoring in marine propulsion, and I find some problem when I try to use the Propeller Free Format(PFF) file. I want to establish a blade model by importing a PFF file, however, I have no idea about expressing the skew parameter of the propeller in a PFF file. I have downloaded the demo PFF file fromhttps://www.caeses.com/blog/2017/introduction-to-pff-propeller-free-format/#respond, and the skew is not presented in this file.  So how can I figure out this problem.

Best regards.

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Hi,

 

Skew is given in the PFF file, by interpreting the dist LE value: post-8-0-65549900-1554802622_thumb.png

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Hi Everyone,

 

I used the Wageningen B-Series online tool to generate a 3D model of a 3 Bladed propeller but now I need 2D drawings. Specifically expanded view, pitch distribution, profile view and transverse view. Is this something CAESES can produce? Can someone help me please?

 

Thanks.

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