Learning Forum

[jp_jason]

Hello Ansys-Community,

I am trying to generate a midsurface of a blade, in order to create a 2D-mesh of shell elements.

[Kishan Konannavar]

Hello
Could you please clarify two points:
1) What are you looking for when you mean midsurface?
2) What steps are you undertaking in order to create the said midsurface in Spaceclaim?

Thank you
Kishan

[jp_jason]

Hello thanks for your quick response.

1) I am looking to generate the midsurface between pressure and suction side of a blade.
2) In spaceclaim there is a function called Midsurface. Unfortunately, it is not possible to select the pressure and suction surface of the blade. For simpler geometries there is no problem.

.Cheers
Jay

[jp_jason]

Hello thanks for your response.
1) I looking to generate the midsurface between pressure and suction side of a blade.
2) In spaceclaim there is a function called Midsurface. Unfortunately, it is not possible to select the pressure and suction surface of the blade. For simpler geometries there is no problem.

.Cheers
Jay

[Kishan Konannavar]

Hello
Could you try making the trailing edge a bit more round rather than keeping an edge there and then give it a try. This would do two things, 1) It could allow you to use the midsurface 2) improve the overall mesh quality for the simulations.
Regards
Kishan

[peteroznewman]

@JayPR
Does the leading edge come to a sharp edge or does it have a radius? If the leading edge has a radius, and the trailing edge comes to a sharp edge, then there are not two sides. To make two sides you will have to split the leading edge radius at some tangent point, which seems to vary through 3D space.
Extracting a surface halfway between two surfaces is not simple. In SpaceClaim, it would be fairly difficult. A surface modelling tool like Rhino is more likely to have tools to find that center surface.
Say you get the center surface, and you mesh the surface with shell elements, how are you going to assign the thickness to each element? I have used NX CAD/CAE software that can generate a midsurface between two nonuniform surfaces, and mesh that midsurface using nodal thickness, so each corner of each quad element has its own thickness. I don't know how to do that in ANSYS.
If you only have ANSYS, I suggest you use solid elements to capture the stiffness of the wing.

[peteroznewman]

[jp_jason]

Hello Peter, hello Kishan thank you very much for your answers. The blade has a very small radius at the LE and TE. I will try to generate the midsurface using Rhino. This seems to me the most optimal solution without changing the geometry of the blade. If this works I will update you.
As I am creating a blade from fiber composites, I need the midsurface as a cut-off geometry. ACP(Pre) allows just the import of shell elements. Only at the end of the ACP-setup a conversion to solid elements is possible.
Many greetings and thanks again
Jay