[Ko_Shine]

Hello,

I have been trying to do simulation on 1.5MW wind turbine blade which is 43.2m long in NUMECA FINE/Turbo. I have done some simulations in ANSYS and exported the geometry to be meshed in AutorGrid. Here I have to mention that this is my first time working with NUMECA. I learned the software through the tutorials provided.

At first, the meshing didn’t go well with the exported geometry leaving me loads of negative cells. Then, what I did was that I extracted aerofoils from the existing geometry and created lofted surface using those aerofoils. In that way, I was able to successfully eliminate the negative cells but according to the mesh quality criteria information from this forum, my mesh can be considered not good enough. I tried to change several different parameters but this (attached) mesh is the best one I got.

For your reference, the parameters which gave me the best mesh quality are as follow:

Wind Turbine Layer Control:
Spanwise Grid Point Number – 137
Wall Cell Width – 1e-4 (which I calculated based on my geometry)
Spanwise Expansion Ratio – 1.49

Wind Turbine: Far Filed Control:
Spanwise Grid Point Number – 65
Percentage Constant Cell – 33
Far Field Thickness – 4.5
Far Field Radius – 243.1
Spanwise Expansion Ratio – 1.29

Wind Turbine: B2B Control:
Number of points – 4343622
Minimum Skewness Angle – 5.138
Maximum Expansion Ratio – 4.186


I have attached my blade geometry, hub and shroud curves, mesh quality, B2B view of the mesh at 50% span, and 3D view of the blade at the root and tip. I would appreciate and would be grateful if someone could comment on the quality and suggest for any further improvements. I have been working on this for the past three weeks. Thank you very much in advance.

blade, hub and shroud 1.jpg

mes quality.jpg

B2B view.jpg

3D view - blade root.jpg

3D view - blade tip.jpg

[Hamidzoka]

hi
I am not a wind turbine expert but I think the low mesh quality is related to the shape of the attached airfoil. Airfoil geometry does not seem to be normal. For instance, unusual curvatures is seen near TE on suction side. Airfoil surfaces should be smooth from LE to TE on both sides. Maybe the reason is insufficient number of points used to define the profile. try increasing the concentration of points specially in regions with high curvature levels.

regards

[Ko_Shine]

Hi Hamid,

Thank you very much for that.

Indeed this is something I have in mind. But actually the blade and airfoil geometries are from 1.5 MW wind turbine which I have already done some simulations. I'll try to smooth the airfoils as much as I can. Please let me get back to you again if I still have problems with the software.

Thank you.

Best regards,
Shine

[lchn1]

Hi Ko_Shine,

I'm now meshing a propeller that similar with yours wind turbine,so I wonder if you can solve my problem that trouble me.
The problem is that at each span the B2B mesh are both OK,but when I generate the 3D mesh there will be negtive cells at the tip of the blade because the airfoil there is very curve.

[Ko_Shine]

Hi Tony,

Thanks for your message.

First of all, please let me mention that I'm not an expert. But I hope I can be of a bit help based on the experiences I recently had while working on wind turbine blades and other blades. Would it be possible for you to describe your problem a little bit more, starting from how you started meshing process? It would also be helpful if you could attach some images of the issues you have.

Thanks!