Propeller blade advance modelisation

[Mr. David Gomez Ariza 0]

Hello every body,

 

So I would like to model a propeller with caeses for that I have a couple of questions I would like your help with:

 

1) It is possible to model a propeller as it is explain in the tutorial but with a custom airfoil? (Taking in to account that the custom airfoil is in the form of an a-dimensional data point files as the one I'm attaching)

 

Note: I already try using the Airfoil paramatrization, but i have trouble using the engine curve to generate the blade.

 

2) As you might be familiar to fabricate a propeller is not possible to have a knife edge trailing edge for the airfoil. I wonder if it is a way to set the  T.E gap in function of the airfoil blending position and the blade radius.

 

Thanks in advance

CP_C_6T_2_5_R0_86.zip

[Mr. Claus Abt 14]

HI David,

All the above is standard. We will get in touch with you asap.

Claus

[Ceyhan Erdem 14]

Hi David,

 

Please find attached the .fdb file created with respect to your point data.

Please note that I removed the first line within the point cloud data, leaving only the coordinates.

 

The feature definition within the case basically loops over the data, creates an interpolation curve seperating the suction side and the pressure side of the airfoil.

 

By the way you can set the T.E gap in function of the airfoil blending position and the blade radius, for example you can obtain the camber within CAESES, using the suction and pressure side curves and afterwards trim the airfoil with a line which is normal to camber using a certain parameter which is defined wrt camber or chord length.

 

Cheers

Ceyhan

airfoil_parametrization.fdb

[Mr. David Gomez Ariza 0]

Hi Ceyhan,

 

Thank you for your answer, but unfortunately does not answer my questions exactly . I had manage to do the same as you did using the Airfoil paramatrization feature uploaded by Joerg. What I'm trying to do now is to reproduce the engine curve method used in the generic blade tutorial  to parametrize the radial variation of a custom airfoil in terms of chord , thickness and camber distributions.  Also thank you for your idea for the T.E gap but now that I'm doing it with a classical Naca Airfoil I realized that this method force me to shorten the chord which if necessary is ok but not ideal. I found out that XFLR5 Xfoil direct design method allow to modify the T.E gap and the blending position which seems to be a good solution but the method is in a black box so I wondered if there was a similar method in CAESES.

 

I apologize if missed something in your explanation.

 

thanks in advance

 

David

[Ceyhan Erdem 14]

Hi David,

 

Please find attached the fdb file prepared for the propeller using your blade profile.

 

What it does basically is; importing your blade profile data, creating a curve and separating it into two, providing a pressure side and a suction side curve.

 

By using these two curves it obtains the thickness and the camber curves.

 

Afterwards the written feature definition, which replaces these two lines with parametrically defined ones, willl help you achieve your goal I guess.

 

Please note that on the meta surface and BRep there exist some warnings caused due to the trailing edge cusp, which I left as is intentionally. You can handle them when you decide on a way to blend the trailing edge.

 

Cheers

Ceyhan

airfoil_parametrization.zip

[Mr. Mattia Brenner 6]

Hi David,

 

maybe the generic blade is not necessarily best suited for your applications, since it is intended for marine propellers. A blade modeling approach using our cylinder transformation might be better. See for example this fan model (and the related webinar videos, where I explained different things related to the model): https://www.caeses.com/forum/index.php?/topic/584-fan-model-from-caesessimscale-webinar/

 

Hope this helps!

 

Cheers,
Mattia

[Mr. David Gomez Ariza 0]

Thank you again Ceyhan, As soon i have time I'll look into the new solution you posted and get back to you.