[CFD_Newby]

Hello all,

can you tell me how I find out the stagger angle of a rotor blade in Numeca dependant on the radial position?

Thanks a lot.
Greetings

Peter

[DarylMusashi]

Dear Peter,

One option can be to use IGG again. Please import the geomTurbo file to get the leading and trailing edges. To compute the stagger angle at a specified radial position you need the two cartesian points of the leading and trailing edge at this radial position.

1. Create a support curve by defining two points. If you want to get the LE/TE cartesian points at r=0.1 the points would be 0.1 0 0 and 0.1 0 1 (assuming z is the rotational axis and it rotates around 0).
2. Geometry -> Create Surface -> Revolution to create a support surface
3. Select this support surface and the pressure side, Geometry -> Create Surface -> Surf-Surf Interaction
4. Select the Leading Edge curve, the Trailing Edge curve and the pressure side curve from (3). Geometry -> Create Point -> Curve-Curve Intersection.

Now you have got two Cartesian Points at a defined radial position for Leading Edge and Trailing Edge to create a support curve from LE to TE.

Does this help you to proceed?

Kind regards
Holger

[CFD_Newby]

The LE/TE cartesian points are given in the geomturbo file right (the 1st row of each section)?. How can I create a curve through cartesian points?
Or maybe you can show your procedure, for example with the tutorial file of the Nasa Rotor.

Greetings

[DarylMusashi]

Yes, you could also use the points from the geomTurbo file, if their radial positions are as desired.

You can create Points with Geometry -> Create Points -> Cartesian Points (and enter the coordinates at the bottom). Then you can draw a polyline with shortcut "p".

Or you can directly press shortcut "p" and enter the coordinates at the bottom. After the second point you see the line. Cancel it now with right-click.

Kind regards
Holger

[CFD_Newby]

But if I already know the cordinates of the points on LE and TE, for example:
18.3475923584498
-2.09971266712883
0.0611248973852931

19.1872759073612
1.57329966833071
4.2232809

why should I do all these steps. I can create a polyline through these points and I get my support curve right?
And if I've created this curve, how can I determine the stagger angle?

Greetings
Peter

[DarylMusashi]

Dear Peter,
the difference is that you can compute with the described method stagger angles at defined radial positions. When you use the geomTurbo file you can only compute the stagger angle at the radial positions of the geomTurbo file. If the provided radial positions in the geomTurbo file are fine for you thats an easier way, you are right.

However you do it, finally you've got a line through leading and trailing edge. Now make use of a second line parallel to the flow direction (z in NUMECA) and compute the angle between both lines.

http://nptel.ac.in/courses/112104117...er_5/4_16.html

Kind regards
Holger

[CFD_Newby]

Ok, so in my example I create a Line through
18.3475923584498
-2.09971266712883
0.0611248973852931

and

18.3475923584498
-2.09971266712883
0

At least, can you tell me how to create an angle between these lines and measure the cord length of the LE/TE-lin cause I have no acces to the online documentation.

Greetings

[DarylMusashi]

Dear Peter,

in the top bar you can use Tools -> Distance to measure the distance between two points.

Secondly, please have a look at the link in my last post. Lambda is the stagger angle you want to calculate. With a second support line you can finally compute the angle between these two lines. You can do this by using Tools -> Angle or calculate it manually.

Secondly, I would recommend to ask your license administrator to create an account for you to have access to the customer area.

Kind regards
Holger

[Hamidzoka]

Hi;
These are too complicated!!!
One easy method is to make a parametric model out of your *.geomturo file using "Autoblade" module. it explicitly reports stagger angle as well as other parameters of blades.

Regards