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Sim File Giving Different Results When Used in Different Projects
Hello QBlade Community,
I recently started running some simulations with the SIL feature and noticed that some simulations ran in the SIL module gave drastically different results (they were diverging) compared to when I ran them using the GUI in the original project file (which wasn’t diverging).
For example, here I share some simulation data plots for when I ran the simulation in the original project file, and for when I ran the simulation in a new project file (I exported the .sim file from the original project and imported it into a blank new project), showing that one diverges while the other doesn’t.
The specific simulation file I refer to is called v1_35.sim, the original project file is called hdarrieus.qpr, and the new project file is called NewProjectTestFile.qpr. Both these project files contain the same simulation file mentioned but give drastically different results for the same. I have attached all these files for your convenience.
I have tried investigating to see what the difference and cause for such different simulation results are but have not been able to identify the problem.
Any help on this matter would be greatly appreciated.
Daniel Román
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Hello Daniel,
you are simulating a high TSR operational point for a VAWT, which involves significant blade-wake interaction—a challenging scenario to simulate.
The divergence in your previous results was likely due to the high degree of wake and blade vortex interaction causing the wake to destabilize. Recent versions of QBlade have addressed this issue by fine-tuning the associated parameters. It’s possible that you compared simulation results from different versions, and the wake instability has been mitigated in the latest version.
Regarding the SIL interface: When you run simulations in the SIL, you can manipulate the turbine during the course of the simulation and store the project afterward. However, starting the simulation from the GUI does not produce the same results. This is because the GUI version of QBlade evaluates the simulation based only on the settings of the simulation definition, without incorporating the user-defined manipulations from the SIL, which are only contained within the SIL script.
I hope this helps.
BR,
David
Hello David,
Thank you for your help David! For the SIL script, I don’t change anything about the simulation while it is advancing, I only record the data but don’t alter anything about it. For example, here is a bit of the MatLab code I used to advance the simulation and record the data:
% TSR = 3.5
QBLIB.loadSimDefinition(‘v1_35.sim’)
QBLIB.initializeSimulation()
Cp_35 = zeros(nb_timesteps,1);
Ct_35 = zeros(nb_timesteps,1);
% simulation
for i = 1:1:nb_timesteps
% advance the simulation
QBLIB.advanceTurbineSimulation()
% save power and thrust coefficients
Cp_35(i) = QBLIB.getCustomData_at_num(‘Power Coefficient [-]’,0,0);
Ct_35(i) = QBLIB.getCustomData_at_num(‘Thrust Coefficient [-]’,0,0);
end
For both the SIL script and the GUI simulations I am using QBlade CE 2.0.7, so I don’t think the issue comes from using different versions of QBlade. Using the same GUI version of QBlade (CE 2.0.7) I ran the same simulation file and got different results depending on whether I was starting the simulation from the original QBlade project or a brand new project with only that simulation file in it.
Please let me know if there is anything else I could check. Thanks again!
Daniel Roman
Hi Daniel Roman,
could you try with the latest release version of QBlade (2.0.7.7.) and let me know if the issue persists?
Previously, file endings of QBlade executables and libraries did not use the minor versioning number, so even though the filenames are both 2.0.7, the versions could still be different.
BR,
David
