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Some questions about Aerodynamic Discretization on Turbine Blades
Dear David:
I would like to ask if I can make half-cosinusoidal blade discretization so that there are only more discrete aerodynamic points on the blade tip side, rather than more points on tip and root sides(both sides)? Since during simulation, I have fast convergence on the tip side, and the relevant data is useful; there is oscillation on the root side instead, the data is also not important for future optimization.
I found that AERO Table discretization type maybe a solution for such question. But it seems to be a little cumbersome, since I have to create many blade sections, and the distribution of the number of sections can vary along the blade spanwise direction. Therefore, if there are any better alternative solutions so that I can achieve half-cosinusoidal discretization based on limited blade sections? Thank you very much!
Best Regards,
Chen,
13/02/2025
Hi Chen,
the AERO option is the only method available for achieving a custom blade discretization (e.g., the half-cosine distribution).
If you prefer not to define the blade sections manually in the GUI, you can export the blade in the .bld ASCII format and modify the blade table programmatically using Python, spreadsheet tools, or similar methods. Once the modifications are complete, you can simply reimport the blade into QBlade.
Regarding the convergence issues in the inner blade sections, you may try:
- Reducing the relaxation factor (part of the “Turbine Gamma Iteration Parameters”) to stabilize the computation.
- Increasing the bound vortex core size to further improve convergence.
BR,
David
I will try. Thank you.
Quote from David on 13. February 2025, 09:02Hi Chen,
the AERO option is the only method available for achieving a custom blade discretization (e.g., the half-cosine distribution).
If you prefer not to define the blade sections manually in the GUI, you can export the blade in the .bld ASCII format and modify the blade table programmatically using Python, spreadsheet tools, or similar methods. Once the modifications are complete, you can simply reimport the blade into QBlade.
Regarding the convergence issues in the inner blade sections, you may try:
- Reducing the relaxation factor (part of the “Turbine Gamma Iteration Parameters”) to stabilize the computation.
- Increasing the bound vortex core size to further improve convergence.
BR,
David
Hello David,
Could you please add the blade discretization option of half-cosinusoidal in the next QBlade version, or some different discretization types according to different parts like XFLR5? Since the mesh can be discretized by parts on wing surface in XFLR5 so that there are more meshes only on the tip side. Thank you.
Best Regards,
Chen
18/02/2025
Hi Chen,
as suggested previously, there are several workarounds available for this. The AERO discretization option, combined with direct modifications to the .bld ASCII file table, should be sufficient for most applications.
For this reason, we do not currently plan to add additional auto-discretization features.
BR,
David
