Control surfaces problem in VSPaero and OpenVSP 3.13.2

[corp...@gmail.com]

Hi all,

I’m currently testing VSPaero with control surfaces modelled, VLM method and I face this problem, that  I hope to explain in a clear manner.

Here the steps:

1. Created flaps and ailerons ( exactly in this order) in Sub- Surface List  in OpenVSP. Control surfaces appear as correctly modelled in the 3D model
   
2. Launch VSP aero
3. In CONTROL SURFACE GROUPING  tab I create one User Group for each control surface appearing in Available Control Surfaces area ( where control surfaces are listed in the same order as modelled)
4. In the OVERVIEW tab, under “Control Group Angles”, all surfaces (flaps+ailerons) are present and activated (yellow dot for all surfaces). I assign the angle of deflection and launch the Solver.

 

Now the problem: only the control surfaces that are grouped first ( that is, modelled first in OpenVSP), are present in the analysis, while the reminder are (for some reason) excluded, although all checks at point 4)

This is evident also in Viewer, where, for each case, only the control surface which was modelled first is shown, although both are checked in the pre-processing.

I tried many combination of grouping and/or ordering but with no results

Has anybody experienced the same problem ?

Thanks in advance for any suggestion.

 

Corrado

[Jasper]

Coming from Corrado's comment in this discussion: https://groups.google.com/forum/#!topic/openvsp/iDoa_PWt8y4

I can reproduce the problem mentioned above. Having a simple wing with both flaps and ailerons, and a vertical tail: only the ailerons, which were modeled before the flaps, and the rudder can be deflected and considered in the analyses. The flaps can still be grouped and selected for analysis/given an angle, but this is ignored in the actual VSPAERO analysis. 

Following is copied from the output in the vspaero gui console:

Could not find control surface: Wing_Surf0_flaps in control surface group: Wing_flaps

Known control surfaces:

vertical_Surf0_rudder

Wing_Surf0_ailerons

Wing_Surf1_ailerons

 

Could not find control surface: Wing_Surf1_flaps in control surface group: Wing_flaps

 

Known control surfaces:

vertical_Surf0_rudder

 Wing_Surf0_ailerons

 Wing_Surf1_ailerons

 

Cheers,

Jasper

[corp...@gmail.com]

Thank you very much Jasper.

Cheers
Corrado

[corp...@gmail.com]

I'm reading right now the presentation of Nick Brake ( VSPAERO GUI Advanced) at the last workshop.

Taken from last page of presentation: " VSPAERO only finds the first control surface definition on a wing".

Therefore, is it correct to say that VSPAERO doesn't handle flaps and ailerons at the same time ?

Corrado

[Rob McDonald]

This is a temporary bug -- we had it fixed, but it got re-introduced.
3.13.3 will fix it again.

Nothing wrong with the fluid mechanics. A problem with how VSPAERO
was parsing the input file written by OpenVSP.

Rob

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[corp...@gmail.com]

Thank you Rob.

Corrado

[Oliver Griffiths]

I am getting a similar problem to this that appears to be persistent up to version 3.23.0. 

I have a wing with 1 control surface group which I have named "Brakes". Ultimately, I wish to include multiple Control_Surf sub-elements in this group but for simplicity, there are only two surfaces in the group "Brakes", named "Brake1" and "Brake2". Like OP, I am able to group the surfaces and can see that the "Brakes" group is active in the Control Group Angles section of the Overview tab. I still get essentially the same error as OP where the second surface in group "Brakes", named "Brake2" cannot be found. Here is the error message...

Could not find control surface: WingGeom_Surf0_Brake2 in control surface group: Brakes

Unless I am missing something this appears to be the same bug. I have tried version 3.13.3, 3.20.0 and 3.23.0. All give the same error. 

Any help would be appreciated.

On Wednesday, September 6, 2017 at 5:12:51 PM UTC+1 corp...@gmail.com wrote:

Thank you Rob.

Corrado

[jvgr...@gmail.com]

Can you post your *.vsp3 file that demonstrates the behavior or provide a step by step method to replicate it? I tried repeating the steps listed in the first comment in this thread and running the model Jasper posted, but everything seems to be working as expected (see attached). 

I have found one bug where if symmetry is turned off after the control surfaces have been added to the group, the symmetric control surface copies still remain in the group. VSPAERO will then indicate that the control surfaces can't be found, but this does not impact the results. 

-Justin 

[Oliver Griffiths]

Thanks for the help. 

I will give further details but am struggling to upload my model at the moment, unfortunately. I have however managed to re-create my problem by editing using Jasper's model. 

The issue arises when I create a Control Group with multiple surfaces and also want to obtain stability derivative data (i.e. in the Advanced tab, Run Mode Section change the Stability Type to Steady). To Jasper's model, I have added a fourth control group called "flapAileron" which simply groups the flaps and ailerons together. I also changed the run mode to Steady Stability Type. 

Running the vspaero solver results in the message...

"Could not find control surface: Wing_Surf0_flaps in control surface group: flapAileron". 

The .stab file produced by this run (which contains information about the aero derivatives and control derivatives) is also empty. 

[ZA Traders]

Hi, Corrado

Did you find the solution to the error?

I am facing exactly the same problem, when I use VLM method for stability analysis, it runs fine and calculate the control derivatives, but when I try to use Panel method it didn't even start the analysis for control derivatives.

Then I have tried to run Panel method using command line,  I get similar error:

Could not find control surface: Wing_Surf0_flaps in control surface group: Wing_flaps

[C P]

ZA Traders,

with referece to my first question above, problem seems solved in release 3.23.

About your problem, control surfaces don't work with Panel method, only VLM.

[Zia Joany]

oh, Okay Thank you a lot.