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Mr. Suraj Pawar

NACA profile with NACA a=0.8 mean line and NACA 66 thickness distibution

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I am trying to generate a profile with NACA a=0.8 meanline and NACA 66 thickness distribution. I created B-spline for camber line and thickness using set of points which are normalized with chord length. After that I created offset curves with thickness distribution and got the blade profile. But I am not getting smooth rounded leading edge. I have attached the snapshot of leading edge. Also, I have information about leading edge radius. But I don't know how I can incorporate that in offset curves.

 

Thank You.

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Dear Mr. Suraj Pawar,

 

This is a case caused by the visualization parameter of the curve being relatively low.

 

If you increase the " Render Resolution " value within the related curve's menu, you will observe that the way the curve looks will be smoother.

By the way this does not affect the geometry when it is exported.

 

For your second question, do you want somehow extrude your profile not along a line but along a curve?

If it is the case, you can simply define your extrusion profile and then under " Surfaces ", create a "Sweep Surface" 

 

Cheers

Ceyhan

post-467-0-46284900-1503068678_thumb.png

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If i have a circle at the leading edge and is there any I can make the offset curves tangential to this circle. I have attached a screenshot. In this screenshot, the blue curve is generated by offset curve of mean camber line and thickness distribution.  And red curve is for leading edge circle. Is there any way I can make blue curve tangential to this circle?

Thank you. 

post-902-0-10308100-1503073837_thumb.png

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I tried using this feature but it does not create the thickness profile the way I want. Currently, I have created a B-spline curve with the help of set of points. I am looking to use a feature like "Fit Profile point data with LE and TE" feature. But for this feature I have to give set of points as an input.

 

For leading edge and trailing edge I have curve in the form of circle. And also for airfoil profile I have curve which is obtained using offset curve with camberline and thickness as input.

 

Is there any way I can get set of offset points with camberline and thickness points as input?

 

Thank You. 

post-902-0-96802000-1503329696_thumb.png

propeller_profile.fdbc

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Hi,

 

i encountered the same issue and tried several "thickness curves" (the feature definition as well).

 

Increasing the "Render Resolution" did not solve it at all. 

 

In the attached picture you can see the angular leading edge. The dotted line in the middle is the camberline and the solid line with applied thickness distribution. 

 

---> The points on the solid line are the points of the control polygon, but even the control polygon is angular. <---

 

 

Kind regards

 

Bastian

post-1110-0-07012200-1554293898_thumb.png

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Hi Bastian,

can you show the thickness distribution?

best regards

Carsten

 

Hi Carsten,

 

in the attached picture you can find two curves i have applied for the thickness distribution within the StreamSection.

 

It is a Naca4DS curve and thicknessdistribution is you proposed.

 

 

Kind regards

 

Bastian

post-1110-0-51155300-1554357583_thumb.png

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Hi Carsten,

 

i hope the following informations are helpful. Furthermore i found a way to circumvent the angular leading edge.

 

In picture "1" you can see three spans. Each span is created with the stream section feature and is related to the same thickness distribution, beta distribution and stream lines. As shown the first profile has an angular leading edge while the others are fine.

 

As soon as the first profile is moved away from the hub surface, the angular leading edge disappears as you can see in picture "2". This is done by adding in an offset for the radius on the stacking shown in picture "3".

 

 

To achieve a suitable blade, i relocated the stream line on the hub by the mentioned offset. I assume this is not the most elegant solution but it works transitionally.

 

 

Kind regards

 

Bastian

 

 

post-1110-0-77022400-1554710304_thumb.jpg

post-1110-0-51777400-1554710311_thumb.jpg

post-1110-0-61485100-1554710451_thumb.jpg

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Hi Bastian,

 

Can you try to extend the hub curve a bit, so that the stacking line does not start at the begin of the hub section?

 

best regards

 

Carsten

 

Hi Carsten,

 

i also found this solution to achieve a round leading edge. Obviously it is not allowed for elements to overtower the "design space" limited by a linear connection between the stream lines. I have tried to visualize in the picture attached if anyone else encounters this issue. 

 

kind regards

 

Bastian

post-1110-0-86641300-1555423029_thumb.jpg

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