Meshing trailing edge of aerofoil in Gambit

[cconsul]

Hey,

when using the boundary layer tool in Gambit to mesh the near wall region of an aerofoil I experience problems at the trailing edge.
The x-direction size of the first cell downstream of the trailing edge appears to be equal to the y-direction cell size along the surface. For y+<5, the latter is very small, i.e. 1e-5, which means that the spacing of the cells in the x-direction downstream of the trailing edge is equally small. This, in turn, renders problems at the interface of the boundary layer and the outer region when using an unstructured mesh - the resolution is poor, skew angles etc.

Does anyone know how to change the configuration, so that the x-direction size of the cells downstream of the trailing edge can be increased (and is not equal to the y-direction size of the cells along the aerofoil surface)?

Many thanks for your comments in advance,

CC

 

[Achy47]

Hello CC,

Thank you for sharing your concerns and issues with using the boundary layer tool in Gambit. The problem you are experiencing at the trailing edge is a common issue that many researchers have encountered while using unstructured meshes.

One approach to address this issue is to use a hybrid mesh, which combines the benefits of both structured and unstructured meshes. With a hybrid mesh, you can have control over the cell size in the near-wall region while maintaining the flexibility of an unstructured mesh in the outer region.

Another approach is to refine the mesh in the near-wall region by adding more nodes and increasing the number of layers in the boundary layer. This will allow for better resolution and can help improve the overall mesh quality.

Additionally, you can also try adjusting the growth rate and stretching parameters in the boundary layer tool to see if that helps with the cell size at the trailing edge.

I hope these suggestions help in improving your mesh and resolving the interface issues. Please let me know if you have any further questions or if these solutions work for you.