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Validation of APC propeller performance data
Hello all,
I am trying to check the suitability of QBLADE for initial propeller characterization, for modeling and simulation of quadrotors. For this aim, I have tried to compare the results against already published data.
I have created models for 2 different APC propellers, for which the manufacturer has published performance data and geometry (via their PE0 geometry file). I have not been able to reproduce the performance data published by APC with enough similarity. The differences I get on thrust (N) are of the order of 60%.
Has anyone attempted such verification? I suspect these discrepancies could be due to my simulation set-up (airfoil polars and/or blade geometry). Some comments on my workflow:
- I set mode to PROP
- I am selecting APC propellers that do not have variable airfoil. The airfoil profile is the same spanwise and I just load standard .dat normalized airfoil data into QBLADE
- I am computing aerodynamic data at the same Mach number and Reynolds number as the one stated by APC for every performance data provided
- I am computing the polar in the range of AOA=[-20,+20], and extending the polar via Viterna method, without modifying any default parameter
- For blade geometry, I include the hub radius, station position, chord and twist as provided by APC. I am also setting the X offset to match the rake data provided by APC at each station
Interestingly, if I set the number of blades to 1, my simulation results seem to match quite well with the performance figures published by APC (differences of 5% in thrust), so it may indicate something I am not doing correctly.
Has anyone attempted to perform such comparison for APC propellers?
Thank you in advance.
Hello,
while we have not specifically validated QBlade against APC propellers, the propeller modeling capabilities in QBlade have been verified against published reference data, most notably the NACA TR-594 propeller, for which both geometry and experimental performance data are publicly available.
A full project model of the TR-594 propeller is included in the /SampleProjects folder in the QBlade installation directory. This case shows good agreement between simulation results and experimental data when the geometry and operating conditions are modeled correctly. In general, both the BEM and LLFVW methods implemented in QBlade are capable of predicting propeller performance with good accuracy for typical propeller configurations.
Without seeing your model, it is difficult to identify the exact cause of the discrepancy, but based on experience, differences of the magnitude you describe are almost always related to geometry definition or airfoil polar input, rather than the solver itself.
Maybe a good next step would be to compare your model setup side-by-side with the TR-594 sample geometry and project setup?
Best regards,
David
