Damien ENGEMANN asked 2 years ago
Hello André,
I was wondering if you can help me with the following problem.
I am sizing the elevator, and I am trying to perform a stability analysis with a control parameter for the elevator surface.
I’ve followed the instructions in the following link
https://flow5.tech/docs/flow5_doc/Tutorials/Stability.html#top
In step 3, I perform the 4 required steps to identify the control parameter, and then on the analysis 3d window, I chose the min max and delta values for the control parameter, (for example 0,5,0.5), and then I run the analysis. (store operating points activated)
but what I end up having is only the 0 control parameter operation point, I checked the log files, and it doesn’t seem to recognize that I assigned a range for the control parameters
Can you point out what I might be missing?
please let me know if I can provide any more details regarding this situation.
Hello Damien,
Things have changed a bit in the latest versions and the online doc needs an update.
Ranges have been disabled in T7 analyses. Instead the control derivatives are calculated using the specified gains at the nominal position of the control surfaces.
If an operating point has been generated, select it, then in the bottom right properties box, scroll down and check that can you can see the control derivatives paragraph.
I may need to revisit the process because it seems with hindsight that the control derivatives should be more naturally included in the T8 analyses.
I’ll give it some thought.
André
Hello André,
One interesting test that I usually used to perform is a stability analysis at various elevator deflection angles, this gave me the trim AOA and the trim performance at each elevator deflection.
in XFLR5 we can perform this but only in inviscid mode, so it was interesting to do so with viscosity activated in FLOW5.
is it possible to enable this feature in a future release?
Unfortunately it wasn’t possible to maintain this functionality with AVL type controls, and I don’t see a way to restore the feature given the application’s structure. Hope that you can manage without.
André